Anderson Orthopaedic Research Institute

2022

May 2022

Do Total Hip Arthroplasty Polyethylene Liners without Free Radicals Oxidize in Vivo or ex Vivo?
Rowell SL, Reyes CR, Hopper RH Jr, Engh CA Jr, Muratoglu OK

Crosslinking substantially reduces the wear of ultra-high molecular weight polyethylene (UHMWPE) used in total hip arthroplasty (THA) but some reports have indicated that first generation liners manufactured without antioxidants may be vulnerable to in vivo oxidation. This study evaluated maximum oxidation using Fourier transform infrared spectroscopy per ASTM F2102-06ε1 and linear head penetration using a coordinate measuring machine among 66 revision-retrieved THA components with in vivo durations ranging from 0.02 to 24.6 years. These included 30 liners crosslinked with 5 Mrad of gamma radiation and then melted, 13 non-crosslinked, never-irradiated liners sterilized with gas plasma and 23 non-crosslinked, never-irradiated liners sterilized with ethylene oxide. All liners were vacuum-sealed and stored at -20°C prior to analysis with the exception of three retrievals of each material type that were stored in air for 9.9 to 21.5 years. All 57 vacuum-sealed and frozen retrievals demonstrated good oxidative stability with maximum oxidation indices (OIs) less than 1.0 and 75% (43/57) of these liners had maximum OIs less than 0.1. Linear penetration measurements were lower in the crosslinked liners compared to non-crosslinked retrievals. Although instances of oxidation and embrittlement were fou nd after ex vivo storage in air among liners that did not have free radicals at the time of implan tation, in vivo oxidation does not appear to be a clinical concern through the first decade of service for crosslinked liners and at up to 25 years after surgery for non-crosslinked liners.

March 2022

Direct Anterior Approach for Primary Total Hip Arthroplasty Lowers the Risk of Dislocation Compared to the Posterior Approach: A Single Institution Experience
Haynes JA, Hopper RH Jr, Ho H, McDonald JF III, Parks NL, Hamilton WG

Background: One purported benefit of the direct anterior approach (DAA) for total hip arthroplasty (THA) is a lower rate of postoperative dislocation. Methods: An institutional database was used to identify 8840 primary THAs performed from 2003 to 2020 including 5065 (57%) performed using the DAA and 3775 (43%) performed via the posterior approach (PA). Direction and mechanism of dislocation were determined from chart review. Outcomes were compared using Kaplan-Meier survivorship with dislocation as the endpoint and a Cox multivariate regression was used to investigate factors associated with dislocation. The mean follow-up was 1.7 ± 2.0 years for the DAA and 3.1 ± 3.3 years for the PA. Results: The 0.5% (26/5065) incidence of dislocation among DAA hips was significantly less than the 3.3% (126/3775) among PA cases (P < .001). The majority of dislocations were posterior (DAA 57%, PA 79%) and occurred during activities of daily living (DAA 82%, PA 77%). Five-year survivorship was significantly higher for the DAA group compared to the PA group (99.1% vs 95.4%, P < .001). Dislocation risk was 4.9 times higher for the PA compared to the DAA (hazard ratio = 4.9, 95% confidence interval = 3.2-7.5, P < .001). Increasing head diameter reduced the risk (hazard ratio = 0.70, 95% confidence interval = 0.57-0.86, P < .001). The 0.2% incidence (10/5065) of revision for instability among the DAA group was significantly lower than the 1.1% (43/3775) rate for the PA group (P < .001). Conclusion: Compared to primary THAs performed with the PA, DAA cases had a lower risk of dislocation, higher survivorship with dislocation as an endpoint, and a lower risk of revision for instability in this single institution cohort. Keywords: direct anterior approach; dislocation direction; femoral head diameter; instability; posterolateral approach; total hip arthroplasty. Copyright © 2021 Elsevier Inc. All rights reserved.

March 2022

AAHKS Best Podium Presentation Research Award: Femoral Perforation During Direct Anterior Approach Total Hip Arthroplasty: Incidence, Cohort Characteristics, and Management
Kinney MC, Ho H, Hamilton WG

Background Cortical perforation during femoral preparation is a recognized complication of total hip arthroplasty (THA) but the incidence, patient characteristics, management, and outcome have not been described for the direct anterior approach (DAA). Methods A database query of all primary and conversion DAA THAs performed by a single surgeon from 2009 to 2021 was used to identify hips that sustained a recognized intraoperative femoral perforation. Radiographs were used to assess stem subsidence, Dorr femur type, and Canal Flare Index. Results Among 3,973 THAs, 16 patients (0.4%) sustained perforations during broaching including 8 males and 8 females with a mean age at surgery of 65.6 (range 41-81) years and a mean body mass index of 31.0 (range 19.0-44.4). Two hips were converted to longer primary cementless stems to bypass the perforation. For the remaining 14, the broach was redirected and the same primary stem was implanted. Limited weight-bearing (6 patients) or protected weight-bearing as tolerated with a walker/cane (10 patients) was advised postoperatively. At a mean follow-up of 18.7 (range 4-105) months, all stems were stable with no fractures, subsidence, or revisions. Factors associated with perforation included difficulty with exposure (body mass index >40 or a contracture), measurable osteoporosis (Canal Flare Index <3.0), and abnormal proximal femoral anatomy due to prior trauma, retained hardware, or Perthes disease. Conclusion In this case series, isolated perforation of an otherwise intact femur during DAA was successfully managed with redirection of the broach, implantation of a primary stem that achieved axial/rotational stability, and protected weight-bearing. Level of evidence IV, Case Series.

March 2022

Randomised Comparative Effectiveness Trial of Pulmonary Embolism Prevention after Hip and Knee Replacement (PEPPER): the PEPPER Trial Protocol
Pellegrini VD, Eikelboom JW, Evarts CM, Franklin PD, Garvin KL, Goldhaber SZ, Iorio R, Lambourne CA, Magaziner J, Magder L, Fricka KB

Introduction: More than 1 million elective total hip and knee replacements are performed annually in the USA with 2% risk of clinical pulmonary embolism (PE), 0.1%-0.5% fatal PE, and over 1000 deaths. Antithrombotic prophylaxis is standard of care but evidence is limited and conflicting. We will compare effectiveness of three commonly used chemoprophylaxis agents to prevent all-cause mortality (ACM) and clinical venous thromboembolism (VTE) while avoiding bleeding complications. Methods and analysis: Pulmonary Embolism Prevention after HiP and KneE Replacement is a large randomised pragmatic comparative effectiveness trial with non-inferiority design and target enrolment of 20 000 patients comparing aspirin (81 mg two times a day), low-intensity warfarin (INR (International Normalized Ratio) target 1.7-2.2) and rivaroxaban (10 mg/day). The primary effectiveness outcome is aggregate of VTE and ACM, primary safety outcome is clinical bleeding complications, and patient-reported outcomes are determined at 1, 3 and 6 months. Primary data analysis is per protocol, as preferred for non-inferiority trials, with secondary analyses adherent to intention-to-treat principles. All non-fatal outcomes are captured from patient and clinical reports with independent blinded adjudication. Study design and oversight are by a multidisciplinary stakeholder team including a 10-patient advisory board. Ethics and dissemination: The Institutional Review Board of the Medical University of South Carolina provides central regulatory oversight. Patients aged 21 or older undergoing primary or revision hip or knee replacement are block randomised by site and procedure; those on chronic anticoagulation are excluded. Recruitment commenced at 30 North American centres in December 2016. Enrolment currently exceeds 13 500 patients, representing 33% of those eligible at participating sites, and is projected to conclude in July 2024; COVID-19 may force an extension. Results will inform antithrombotic choice by patients and other stakeholders for various risk cohorts, and will be disseminated through academic publications, meeting presentations and communications to advocacy groups and patient participants.

February 2022

Factors Associated with the Incidence and Timing of Total Knee Arthroplasty Infection
Hasenauer MD, Ho H, Engh CA III, Engh CA Jr

Background: Periprosthetic joint infection (PJI) following total knee arthroplasty remains a challenging clinical problem. This study examined variables related to the incidence and timing of PJI. Methods: We retrospectively reviewed 8462 primary total knee arthroplasties performed at our institution between 2006 and 2018 for PJI. The mean follow-up is 3.7 years. Eighty-seven variables including patient-reported diagnoses, demographics, and medications were collected. Time to infection, bacterial organism, success of infection treatment, and variables associated with infection are reported. Results: PJI occurred in 105 (1.24%) cases. The incidence of infection in the first year was 0.72% and represented 58% of all infections. Multivariate Cox regression revealed males (hazard ratio [HR] = 2.85, 95% confidence interval [CI], 1.69-4.79) and patients with major depression or anxiety (HR = 2.11, 95% CI, 1.21-3.67) were more likely to develop an infection in the first year. After the first year, patients with a history of cellulitis (HR = 3.97, 95% CI, 1.91-8.27) and those taking antiepileptic medications (HR = 3.61, 95% CI, 1.73-7.52) were more likely to develop an infection. Culture-negative infections were more common after one year than before (23% vs 8%, P = .04). Debridement, antibiotics, and implant retention was used in 79% (48/61) of infections in the first year and 55% (24/44) after one year with success rates of 51% and 70%, respectively (P = .16). Conclusion: The majority of infections occur during the first year after surgery. Importantly, patient variables associated with infection are different among infections that occur before and after one year. A multicenter study with a much larger number of infections may allow analysis of more time intervals after surgery. Keywords: bacterial organism; debridement, antibiotics, and implant retention treatment outcome; patient-reported diagnoses; periprosthetic joint infection timing; primary total knee arthroplasty.

February 2022

Early Results of a Randomized Controlled Trial of Partial Versus Total Knee Arthroplasty
Sershon RA, Fricka KB, Hamilton WG, Nam D, Parks NL, DeBenedetti A, Della Valle CJ

Background: Debate still exists regarding the benefits of unicompartmental (UKA) versus total knee arthroplasty (TKA) for the treatment of medial compartment osteoarthritis. The purpose of this randomized trial is to compare the early outcomes of UKA versus TKA. Methods: One-hundred and seven candidates for UKA were randomized at two centers; 57 candidates received UKA and 50 received TKA. Six-week and 6-month outcome measures including Knee Injury and Osteoarthritis Outcome Score, Joint Replacement (KOOS, JR), Knee Society Score (KSS), Forgotten Joint Score (FJS), and VR-12 global health scores were obtained. No demographic or baseline patient reported outcome (PRO) differences were present suggesting successful randomization (P > .05). Results: UKA demonstrated shorter operative times (UKA = 65 minutes, TKA = 74 minutes; P < .001) and length of stay (UKA = 0.7 nights, TKA = 1.2 nights; P < .01). At 6 weeks, there were no differences in KOOS, JR (P = .755), KSS (P = .754), FJS (P = .664), or PRO change from preoperative scores (P = .468). There were three surgical complications within 90 days in each group. The duration of opioid consumption (UKA = 33.8 days, TKA = 28.5 days; P = .290) and return to work (UKA = 57.1 days, TKA = 47.3 days; P = .346) did not differ between groups. Conclusion: Data suggest no clinically significant differences between UKA and TKA in the early postoperative period in regards to patient-reported outcome measures, duration of opioid use, or return to work. Patients undergoing UKA can anticipate a shorter length of stay and greater early range of motion. All-cause short-term complications may be more prevalent with TKA. Keywords: knee; osteoarthritis; outcome; partial knee replacement; total knee replacement.

February 2022

Does Approach Influence the Dislocation Rate following Head and Liner Exchange in Revision Hip Arthroplasty?
Robertson RN, Parks NL, Ho H, Hopper RH Jr, Hamilton WG

Background: Revision total hip arthroplasty with modular component exchange can limit morbidity by retaining well-fixed components but dislocation has been a relatively frequent postoperative complication. This study evaluated the effect of surgical approach on dislocation rate in a modern revision cohort. Methods: From 2010 to 2020, 248 aseptic head and liner exchanges were performed at a single institution. The mean patient age at revision was 64.9 ± 10.4 years and 50% (123/248) were performed among males. Indications for revision included 140 (56%) for polyethylene wear, 68 (27%) for failed metal-on-metal components, and 40 (16%) for instability. The mean follow-up after revision was 2.3 years. Results: Thirty (12%) hips dislocated at a mean of 0.6 years (range 0.01-4.6) postoperatively. The dislocation rate by revision approach was 17% (9/54) for the direct anterior, 6% (5/80) for the direct lateral, and 14% (16/114) for the posterolateral approach (P = .13). Hips revised by the direct anterior approach that dislocated were more abducted (51 ± 8 vs 45 ± 8, P = .05) and more anteverted (26 ± 9 vs 20 ± 7, P = .04) than non-dislocators. Among all 248 hips, cups with more than 48° of abduction were 2.6 times more likely to dislocate (P = .01). Head diameter, neck length, patient age, and gender were not associated with dislocation (P ≥ .20). Conclusion: Dislocation remains a common complication after head and liner exchange regardless of approach. Cup position is associated with postoperative instability and must be critically evaluated during preoperative planning. Keywords: acetabular liner; dislocation; femoral head; revision total hip arthroplasty; surgical approach.

February 2022

Uncemented Collared Femoral Stems in Total Hip Arthroplasty
Lemme NG, McDonald CL, Hamilton WG, Crisco JJ, Cohen EM

The procedure of total hip arthroplasty (THA) is rapidly evolving. Patients undergoing THA are younger and more active, and they demand an earlier return to their daily activities. All of these factors increase both the early forces on uncemented femoral stems and the risk for complications. Consequently, surgeons must choose implants that provide immediate primary stability. This has led to renewed interest in the use of uncemented collared stems, which have benefits including increased primary stability, decreased risk of subsidence and periprosthetic fracture, and improved load transfer to the proximal femur. [Orthopedics. 2022;45(3):e122-e126.].

February 2022

Prospective Randomized Study Using Pharmacogenetics to Customize Postoperative Pain Medication following Hip and Knee Arthroplasty
Hamilton WG, Gargiulo JM, Reynolds T, Parks NL

Background: The purpose of this study is to determine whether pharmacogenetic testing could be used to effectively customize postoperative pain medicine following total joint replacement. Methods: Buccal swabs were collected preoperatively from 107 patients. Pharmacogenetic testing was performed for genetic variants on a panel of 16 genes, including CYP2D6, CYP2C9, OPRM1, and CYP1A2, which affect the pharmacodynamics and pharmacokinetics of non-steroidal anti-inflammatory drugs and many opioids. Patients were randomized to a control group or custom group and blinded to their group. The control group was prescribed oxycodone, tramadol, and celecoxib for postoperative pain management. If any of those were not normally metabolized, they were not prescribed to the patients in the custom group, who were given an alternative drug (hydromorphone for narcotics, meloxicam for non-steroidal anti-inflammatory drugs). Patients recorded their pain level (0-10 numeric scale) and all medications taken daily for the first 10 days following surgery. Medication was converted to milligram morphine equivalents (MMEs). Results: Genetic variations to medications in our standard postoperative pain management protocol occurred in 24 of the 107 patients (22.4%). The 10-day MME consumed by patients in the control group with genetic variants was 162.6 mg. Patients with variants who had custom postoperative medication consumed only 86.7 MME in the same timeframe (P = .126). The control group demonstrated a higher 10-day average pain level of 4.2 vs the custom group pain level of only 3.1 (P < .05). Conclusion: With custom postoperative pain prescriptions based on pharmacogenetic testing, patients were able to achieve lower pain levels while reducing the consumption of pain medication. Keywords: opioids; pain management; pharmacogenetics; total hip arthroplasty; total joint replacement; total knee arthroplasty.

February 2022

Prior Anterior Cruciate Ligament Reconstruction Does Not Compromise the Functional Outcomes of Medial Unicompartmental Knee Arthroplasty Although Revision for Progressive Arthritis May Occur Earlier
Haffer A, Ali R, Mehta N, Patel A, Fricka KB, Della Valle CJ, Gerlinger TL, Krueger CA,Lonner JH

Background: Anterior cruciate ligament (ACL) deficiency is commonly considered a contraindication for unicompartmental knee arthroplasty (UKA). The purpose of this study is to compare the outcomes of UKA after prior ACL reconstruction (rACL cohort) to UKA with an intact native ACL (nACL cohort). Methods: Forty-five patients from 3 institutions who underwent medial UKA after prior rACL were matched by age, gender, preoperative function scores, and body mass index to 90 patients who underwent UKA with an intact nACL. Primary outcomes were Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, Oxford Knee Scores, Knee Society Functional Scores, and Kellgren-Lawrence scores in the unresurfaced, lateral tibiofemoral compartment. Secondary outcomes were postoperative complications and the need for revision to TKA. Results: At a mean of 3.6 years, all PROMs improved significantly with no differences identified between groups. The incidence of revision TKA was similar between cohorts (P = 1.00); however, the mean time to revision for progressive osteoarthritis was 4.0 years in the nACL group and 2.2 years in the rACL group. Twenty percent of rACL patients had a postoperative complication compared to 8% in the nACL group. Despite presenting with a similar degree of lateral arthritis, a greater percentage of patients developed Kellgren-Lawrence scores of ≥3 in the rACL cohort (9%) than in the nACL cohort (0%). Conclusion: A previously reconstructed ACL does not appear to compromise the short-term functional outcomes of UKA; however, there is a higher rate of minor complications and progression of lateral compartment arthritis, which should be considered with patients in the shared decision process. Keywords: ACL reconstruction; anterior cruciate ligament; complications; outcomes; progressive osteoarthiritis; unicompartmental knee arthroplasty.

February 2022

A Postmortem Analysis of Polyethylene Damage and Periprosthetic Tissue in Rotating Platform and Fixed Bearing Tibial Inserts
Chen JB, Baral EC, Hopper RH Jr, McDonald JF III, Koff MF, Potter HG, Bauer TW, Engh CA Jr, Wright TM, Padgett DE

Background: Mobile bearing designs are intended to reduce wear, but mixed results were reported from retrieval analyses. Postmortem evaluation (PM) provides the opportunity to assess polyethylene damage in successful implants. We compared damage patterns, MRI presentation, and histology between mobile-bearing and fixed tibial inserts retrieved postmortem and compared these results to our prior findings from implants retrieved at revision. Methods: Eleven postmortem knees with rotating platform (RP) implants and 13 with fixed bearing (FB) implants were examined. All were MRI scanned, and tissue samples were collected from standardized regions for histology. Polyethylene inserts were subjectively scored to assess articular, backside, and PS post surfaces for damage modes and severity. Results: Average duration of implantation was 9.3 years (1.7-19.6 years). Surface burnishing was the most common polyethylene damage mode. Average damage scores were higher for RP (53.4) compared to FB inserts (34.4) due to greater backside damage (13.4 for RP vs 1.4 for FB). A minimal difference in damage was observed on the articular surfaces (37.4 RP vs 30.0 FB). Mild innate macrophage reactions were seen in 8 (72.7%) RP and 5 (45.5%) FB specimens. Polyethylene particles were identified in 7 (63.6%) RP and 3 (27.7%) FB specimens. Conclusions: Postmortem inserts showed low damage levels and mild tissue reactions compared to those reported for implants removed at revision arthroplasty. Nonetheless, trends in comparing RP and FB inserts were consistent with those seen in retrieval analyses, demonstrating the usefulness of retrieval studies in capturing performance differences among TKA designs. Keywords: bearing; fixed bearing; knee; polyethylene; polyethylene damage; postmortem; rotating platform; tibia.

January 2022

Long-Term Results of Delta Ceramic-on-Ceramic Total Hip Arthroplasty
Blumenfeld TJ, Politi J, Coker S, O’Dell T, Hamilton WG

Background: Ceramic-on-ceramic (COC) bearings in total hip arthroplasty (THA) have long been considered the coupling with the lowest overall wear. However, concerns about complications such as ceramic breakage and noise, combined with the improved performance of polyethylene, have limited its use in the United States. This postapproval follow-up reports long-term (10 years) results of Delta COC in THA patients primarily enrolled in an Investigational Device Exemption study. Methods: Patients received Delta COC THA in a prospective multicenter study with either 28-mm (N = 105 hips in 104 patients) or 36-mm (N = 81) articulations. Annual clinical and radiographic evaluations were performed for years 5 to 10, and study patients were asked about hip noises and reproducibility. Results: There have been 4 additional reports of noise in 4 patients (COC 28, n = 3; COC 36, n = 1). The cumulative incidence rate for squeaking or noise at 10 years is 5.9% for COC 28 and 13.5% for COC 36. There have been 2 additional reports of dislocation in 2 patients (COC 28, n = 1; COC 36, n = 1). The cumulative incidence rate for dislocation at 10 years is 3.7% for COC 28 and 3.5% for COC 36. At 10 years, there were greater than 40 hips available for follow-up. At mean 10-year follow-up, there were a total of 3 ceramic liner fractures, but none since the previous report. There were no revisions in the 28-mm cohort, and 2 revisions in the 36-mm cohort (1 for recurrent dislocation and 1 for pain and noise). Overall Kaplan-Meier survivorship was 95.96% at 10.5 years (28 mm: 97.68% at 10.2 years; 36 mm: 94.11% at 10.4 years.). Conclusions: At 10-year follow-up, we report excellent results in regard to survivorship, with one patient revised for pain with associated squeaking. Keywords: Bearing surfaces; Ceramic; Long-term outcomes; Outcomes; Total hip arthroplasty; Total hip replacement.

Year

2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010

2021

December 2021

Alignment in Medial Fixed-Bearing Unicompartmental Knee Arthroplasty: The Limb Has a Leg Up on the Component
Slaven SE, Cody JP, Sershon RA, Ho H, Hopper RH Jr, Fricka KB

Background: To assess how implant alignment affects unicompartmental knee arthroplasty (UKA) outcome, we compared tibial component alignment of well-functioning UKAs against 2 groups of failed UKAs, revised for progression of lateral compartment arthritis ("Progression") and aseptic loosening ("Loosening"). Methods: We identified 37 revisions for Progression and 61 revisions for Loosening from our prospective institutional database of 3351 medial fixed-bearing UKAs performed since 2000. Revision cohorts were matched on age, gender, body mass index, and postoperative range of motion with "Successful" unrevised UKAs with minimum 10-year follow-up and Knee Society Score ≥70. Tibial component coronal (TCA) and sagittal (TSA) plane alignment was measured on postoperative radiographs. Limb alignment was quantified by hip-knee-ankle (HKA) angle on long-leg radiographs. In addition to directly comparing groups, a multivariate logistic regression examined how limb and component alignments were associated with UKA revision. Results: In the Progression group, component alignment was similar to the matched successes (TCA 3.6° ± 3.5° varus vs 5.1° ± 3.5° varus, P = .07; TSA 8.4° ± 4.4° vs 8.8° ± 3.6°, P = .67), whereas HKA angle was significantly more valgus (0.3° ± 3.6° valgus vs 4.4° ± 2.6° varus, P < .001). Loosening group component alignment was also similar to the matched successes (TCA 6.1° ± 3.7° varus vs 5.9° ± 3.1° varus, P = .72; TSA 8.4° ± 4.6° vs 8.1° ± 3.9°, P = .68), and HKA was significantly more varus (6.1° ± 3.1° varus vs 4.0° ± 2.7° varus, P < .001). Using a multivariate logistic regression, HKA angle was the most significant factor associated with revision (P < .001). Conclusion: In this population of revised UKAs and long-term successes, limb alignment was a more important determinant of outcome than tibial component alignment. Level of evidence: Level III case-control study. Keywords: component alignment; hip-knee-ankle angle; mechanical alignment; medial compartment aseptic loosening and subsidence; revision for progression of lateral compartment osteoarthritis; unicondylar knee arthroplasty.

December 2021

Comparison of Existing and New Total Knee Arthroplasty Implant Systems From the Same Manufacturer: A Prospective, Multicenter Study
Hamilton WG, Brenkel IJ, Barnett SL, Allen PW, Dwyer KA, Lesko JP, Kantor SR, Clatworthy MG

Introduction: This study evaluated total knee arthroplasty (TKA) outcomes for an Existing-TKA versus New-TKA from the same manufacturer. Methods: TKA outcomes for 752 with Existing-TKA versus 1129 subjects with New-TKA were followed through 2 years using patient-reported outcome measures (PROMs). Responders were assessed per Outcome Measures in Rheumatology-Osteoarthritis Research Society International criteria. Kaplan-Meier implant survivorship was estimated. Radiographs had an independent radiographic review. Results: Two-year follow-up was 84.6% (636/752) for Existing-TKA and 82.5% (931/1129) for New-TKA. Two-year PROMs mean outcomes for New-TKA versus Existing-TKA at 2 years were: Knee Injury and Osteoarthritis Outcome Score (ADL: 89.0 versus 86.8, P = 0.005; pain: 88.9 versus 87.1, P = 0.019; symptoms: 84.1 versus 82.2, P = 0.017; Sport/Rec: 63.9 versus 58.8, P = 0.001; and QOL: 77.0 versus 73.5, P = 0.003), Patient's Knee Implant Performance (overall: 76.5 versus 73.5, P = 0.003; confidence: 8.4 versus 8.1, P = 0.004; stability: 8.6 versus 8.3, P = 0.006; satisfaction: 8.3 versus 8.1, P = 0.042; and modifying activities: 6.6 versus 6.4, P = 0.334), Oxford Knee Score (41.9 versus 41.1, P = 0.027), and EQ5D-3L (0.88 versus 0.88, P = 0.737). Two-year responder rates using WOMAC were 93.9% versus 90.6% (P = 0.018) for New-TKA versus Existing-TKA. Independent radiographic review showed that tibial and femoral radiolucencies ≥2 mm were similar (P ≥ 0.05) or favored New-TKA. Implant survivorship was similar between groups (log-rank P = 0.9994). Discussion: New-TKA versus Existing-TKA demonstrated slightly better PROMs with similar radiographic and implant survivorship outcomes. Trial registration: ClinicalTrials.gov NCT01497730 NCT01746524.

September 2021

The Effect of Intraoperative Radiographs on Component Position and Leg Length during Routine Posterior Approach Total Hip Arthroplasty
Brown NM, McDonald JF III, Sershon RA, Hopper RH Jr

Purpose: Accurate component placement and restoration of patient anatomy are critical in total hip arthroplasty (THA) surgery. Although intraoperative radiographs are sometimes utilized, it is unclear whether this practice can improve accuracy. Materials and methods: This study evaluated acetabular cup abduction, anteversion, leg length, and offset among 100 posterior approach THAs performed without imaging (No X-ray group) and compared them to a subsequent series of 100 THAs where an intraoperative radiograph was taken with the trial components in place (X-ray group). THAs were performed using a posterior approach by a single, experienced surgeon whose goal was to place the cup at 45° of abduction and 30° of anteversion. Supine anteroposterior pelvic digital radiographs taken at the first (nominal 4-week) postoperative visit were used for measurements. Results: Slight differences in cup abduction (47°±6° vs 44°±6°, respectively, P=0.003) and anteversion angle (35°±6° vs 31°±6°, respectively, P<0.001) were observed between the X-ray and No X-ray groups; however, a similar proportion of cups within 10° of the target angles was observed (76% vs 83%, respectively, P=0.22). No difference in offset measurements (1.1±6.6 mm vs 0.3±6.9 mm, respectively, P=0.42) or leg lengths (0.3±3.8 mm vs 0.3±4.8 mm, respectively, P=0.94) was observed between the X-ray and No X-ray groups; however, the X-ray group showed less leg length variation (P=0.05). Conclusion: In this study, the routine use of intraoperative radiographs was not associated with improved implant positioning for uncomplicated primary THA. Keywords: Arthroplasty; Hip; Replacement; X-rays.

August 2021

Commentary on The Dangers of Opioids: More Than Just Addiction
Hamilton WG

No abstract available

July 2021

Results of the First US FDA-Approved Hip Resurfacing Device at 10-Year Follow-up
Su EP, Ho H, Bhal V, Housman LR, Masonis JL, Noble JW Jr, Hopper RH Jr, Engh CA Jr

Background: The BIRMINGHAM HIP Resurfacing (BHR) system is a metal-on-metal hip implant system approved by the U.S. Food and Drug Administration in 2006. The approval required a multicenter, prospective, post-market-approval study. Our purpose is to report the current results at 10 years of follow-up. Methods: Between October 2006 and December 2009, 280 primary BHR procedures were performed at 5 sites. Outcome measures included Kaplan-Meier survivorship, reasons for revision, radiographic component stability and osteolysis, Harris hip scores, and metal levels including cobalt and chromium. The mean age at the time of the procedure was 51.3 ± 7.1 years, 74% (206) of 280 BHRs were implanted in male patients, the mean body mass index was 27.8 ± 4.4 kg/m2, and 95% (265) of 280 hips had a primary diagnosis of osteoarthritis. The mean follow-up among all 280 hips was 9.0 ± 2.5 years. Prior to 10-year follow-up, 20 hips were revised and 5 patients representing 5 hips had died. Among the remaining 255 hips, 218 (85%) met the minimum follow-up of 10 years. Results: The 10-year survival free from all-cause component revision was 92.9% (95% confidence interval [CI], 89.8% to 96.1%) for all hips and 96.0% (95% CI, 93.1% to 98.9%) among male patients <65 years old at the time of the procedure. Reasons for revision included femoral loosening (n = 5), femoral neck fracture (n = 3), pseudotumor (n = 3), osteolysis (n = 2), and acetabular loosening (n = 1), as well as 6 revisions for a combination of pain, noise, or metal levels. Among unrevised hips, the median Harris hip score improved from preoperatively (59) to 1 year postoperatively (99; p < 0.001) and remained stable through 10 years postoperatively (99; p = 0.08). Radiographically, 5% (10) of 218 unrevised hips had osteolysis with no component migration. Median metal levels had increased at 1 year postoperatively (cobalt: from 0.12 ppb preoperatively to 1.5 ppb at 1 year postoperatively, p < 0.001; chromium: from 0.6 ppb preoperatively to 1.7 ppb at 1 year postoperatively, p < 0.001), then remained stable thro ugh 5 years before slightly decreasing at 10 years postoperatively (cobalt: 1.3 ppb, p < 0.001; chromium: 1.4 ppb, p < 0.001). Conclusions: This prospective, multicenter, post-market-approval study demonstrated that the BHR implant system is safe and effective through 10 years of follow-up, particularly among young male patients. Level of evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

July 2021

Periprosthetic Femur Fracture Risk: Influenced by Stem Choice, Not Surgical Approach
Sershon RA, McDonald JF III, Ho H, Hamilton WG

Periprosthetic femur fracture (PFF) remains a common reason for failure after total hip arthroplasty (THA). For over 10 years, our institution has performed both anterior approach (AA) and posterolateral (PL) approaches for primary THA with multiple stem designs. The aim of this study is to determine the 90-day relative risk of PFF with regard to approach and stem design. A retrospective review of our institutional database was performed on all patients undergoing primary THA from 2007 to 2018 using AA or PL approaches. Five surgeons performing 6309 THAs (AA = 4510; PL = 1799) using single-wedge taper (n = 2417) or fit-and-fill (n = 3892) stems were included. PFF occurring within 90 days of the index procedure were analyzed. Differences in PFF rates, fracture location, stem type, and treatment method were assessed. Comparisons were made using a Cox regression analysis. The 90-day revision rate for fracture was 0.3%. Clinically significant fractures requiring cerclage cabling, stem change, revision, or open reduction internal fixation occurred in 0.9% of patients (intraoperative = 37, 0.6%; postoperative = 17, 0.3%). Cox regression found PFF risk was significant for female patients (P = .008), patients older than age 65 (P < .01), single-wedge taper stems (P = .05), and for cases with collarless stems (P = .04). Among PFF cases that required surgical intervention, risk factors were female sex, age older than 65, and body mass index under 25 (P < .05). Collarless stems were 2.6 times more likely to result in PFF than collared stems (P = .04). Single-wedge taper stems were 2.3 times more likely to result in PFF than fit-and-fill stems (P = .05). Approach was not found to be an independent risk factor for PFF (P = .85). Our single-center experience demonstrates the risk of periprosthetic fracture within 90 days of surgery is significantly lower with collared stems and fit-and-fill stem designs. Female sex, age over 65, and body mass index below 25 nearly double the PFF risk. Surgical approach did not influence fracture rates.

June 2021

A Comparison of Metal-on-Metal and Ceramic-on-Metal Taper-Trunnion Modular Connections in Explanted Total Hip Replacements
Cadel ES, Topoleski T, Vesnovsky O, Anderson CR, Hopper RH Jr, Engh CA Jr, Di Prima MA

Corrosion and wear are commonly found at the taper-trunnion connection of modular total hip arthroplasty (THA) explanted devices. While metal/metal (M/M) modular taper-trunnion connections exhibit more wear/corrosion than ceramic/metal (C/M) modular taper-trunnion connections, damage is present in both, regardless of material. This study used a combination of assessment techniques including clinical data, visual scoring assessment, optical imaging, profilometry, and x-ray photoelectron microscopy (XPS), to investigate wear mechanisms and damage features at the modular taper-trunnion connection of 10 M/M and 8 C/M explanted THAs. No correlation was found between any demographic variable and corrosion wear and assessment scores. All assessment techniques demonstrated that the stem trunnions had more damage than head tapers for both explant groups and agreed that C/M explants had less corrosion and wear compared to M/M explants. However, visual assessment scores differed between assessment techniques when evaluating the tapers and trunnions within the two groups. Profilometry showed an increase (p <.05) in surface roughness for stem trunnions compared to head tapers for both explant groups. X-ray photoelectron spectroscopy performed on deposits from two M/M explants found chromium and molybdenum carbides beneath the surface while chromium sulfate and aged bone mineral were found on the surface suggesting that the debris is a result of corrosion rather than wear. These results indicate that taper-trunnion damage is more prevalent for M/M explants, but C/M explants are still susceptible to damage. More comprehensive analysis of damage is necessary to better understand the origins of taper-trunnion damage.

2020

November 2020

The Optimal Dosing Regimen for Tranexamic Acid in Revision Total Hip Arthroplasty
Sershon RA, Fillingham YA, Abdel MP, Malkani AL, Schwarzkopf R, Padgett DE, Vail TP, Nam D, Nahhas C, Culvern C, Della Valle CJ, The Hip Society

The purpose of this multicenter, randomized trial was to determine the optimal dosing regimen of tranexamic acid (TXA) to minimize perioperative blood loss in revision total hip arthroplasty. Six centers prospectively randomized 175 patients to 1 of 4 regimens: (1) 1-g intravenous (IV) TXA prior to incision (the single-dose IV group), (2) 1-g IV TXA prior to incision followed by 1-g IV TXA after arthrotomy wound closure (the double-dose IV group), (3) a combination of 1-g IV TXA prior to incision and 1-g intraoperative topical TXA (the combined IV and topical group), or (4) 3 doses totaling 1,950-mg oral TXA (the multidose oral group). No significant differences were found between TXA regimens when evaluating reduction in hemoglobin (p = 0.95), calculated blood loss (p = 0.90), or transfusion rates (p = 0.96). Equivalence testing revealed that all possible pairings were statistically equivalent, assuming a >1-g/dL difference in hemoglobin reduction as clinically relevant. There was 1 venous thromboembolism, with no differences found between groups (p = 1.00). All 4 TXA groups tested had equivalent blood-sparing properties in the setting of revision total hip arthroplasty, with a single venous thromboembolism reported in this high-risk population. Based on the equivalence between groups, surgeons should utilize whichever of the 4 investigated regimens is best suited for their practice and hospital setting. Given the transfusion rate in revision total hip arthroplasty despite TXA utilization, further work is required in this area.

September 2020

Effect of a Clean Surgical Airflow Layer on the Incidence of Infection in Total Hip Arthroplasty
Routh LK, Parks NL, Gargiulo JM, Hamilton WG

The Center for Health Design estimates that more than 30% of surgical site infections are caused by airborne pathogens. A device that creates a localized clean air field directly adjacent to and surrounding the incision site is meant to shield a surgical site from particulate in the operating room. The purpose of this study was to determine whether the routine use of this device would reduce the rate of infection following total hip arthroplasty (THA). The authors conducted a retrospective review of primary THA cases performed with and without the airflow device. Since July 2013, a total of 1093 primary THA cases were performed with the device at the authors’ institution. The incidence of wound dehiscence and deep infection was compared with that of 1171 THA cases performed prior to July 2013 without the airflow device. There were no significant differences between the study groups regarding average patient age, sex, body mass index, or diagnosis. In the airflow group, there were 7 (0.64%) deep infections and 5 (0.46%) cases of wound dehiscence that required a return to the operating room for irrigation and wound revision. In the control group, there were 7 (0.60%) cases of deep infection and 4 (0.34%) wound revisions. The groups were not significantly different in the rates of infection (P=1.0) or wound revision (P=.75). Both groups had a very low incidence of infection and wound revision, with rates below 1%. Despite compelling bench data showing a dramatic reduction of particle load in the wound, the use of the airflow device did not reduce the clinical rate of infection over a large number of cases.

July 2020

Have Newer Bearing Surfaces Changed Expectations Regarding the Longevity of Total Hip Arthroplasty?
Engh CA Jr., McAsey CJ, Cororaton AD, Ho H, Hopper RH Jr

The purpose of this study is to examine six types of bearing surfaces implanted at a single institution over three decades to determine whether the reasons for revision vary among the groups and how long it takes to identify differences in survival. We considered six cohorts that included a total of 1,707 primary hips done between 1982 and 2010. These included 223 conventional polyethylene sterilized with γ irradiation in air (CPE-GA), 114 conventional polyethylene sterilized with gas plasma (CPE-GP), 116 crosslinked polyethylene (XLPE), 1,083 metal-on-metal (MOM), 90 ceramic-on-ceramic (COC), and 81 surface arthroplasties (SAs). With the exception of the COC, all other groups used cobalt-chromium (CoCr) femoral heads. The mean follow-up was 10 (0.008 to 35) years. Descriptive statistics with revisions per 100 component years (re/100 yr) and survival analysis with revision for any reason as the endpoint were used to compare bearing surfaces. XLPE liners demonstrated a lower cumulative incidence of revision at 15 years compared to the CPE-GA and CPE-GP groups owing to the absence of wear-related revisions (4% for XLPE vs 18%, p = 0.02, and 15%, p = 0.003, respectively). Revisions for adverse local tissue reactions occurred exclusively among the MOM (0.8 re/100 year) and SA groups (0.1 re/100 year). The revision rate for instability was lower among hips with 36 mm and larger head sizes compared to smaller head sizes (0.2% vs 2%, p < 0.001). The introduction of XLPE has eliminated wear-related revisions through 15-year follow-up compared to CPE-GP and CPE-GA. Dislocation incidence has been reduced with the introduction of larger diameter heads but remains a persistent concern. The potential for adverse local tissue reactions with MOM requires continued follow-up.

June 2020

Bone Attachment on a New Design of Cementless Stem and a Widely Used Cup; Postmortem Retrieval Findings
Gilmartin NF, Hamilton WG, Park SH, Al-Shihabi L, Campbell P

This was a postmortem retrieval study to assess bone fixation in a hydroxyapatite-coated ACTIS stem and a beaded Pinnacle Sector cup retrieved from an 89-year-old man 15-months postoperatively. Previous radiographic examinations showed good implant fixation without any radiolucency. The sectioned cup and stem showed good fixation on visual, microradiographic, and histological examinations. Slight changes in bone density and mineral content were observed. Clinical fixation was achieved in both components with variable degrees of bone ingrowth and ongrowth at 15 months postoperatively in this postmortem retrieval case.

June 2020

Using Pharmacogenetics to Structure Individual Pain Management Protocols in Total Knee Arthroplasty: A Randomized Pilot Study
Hamilton WG, Gargiulo JM, Parks NL

The purpose of this study was to use pharmacogenetics to determine the frequency of genetic variants in our total knee arthroplasty (TKA) patients that could affect postoperative pain medications. Pharmacogenetic testing evaluates patient DNA to determine if a drug is expected to have a normal clinical effect, heightened effect, or no effect at all on the patient. It also predicts whether patients are likely to experience side effects from medicine. We further sought to determine if changing the multimodal programme based on these results would improve pain control or reduce side effects. In this pilot study, buccal samples were collected from 31 primary TKA patients. Pharmacogenetics testing examined genetic variants in genes OPRM1, CYP1A2, CYP2B6, CYP2C19, CYP3A4, CYP2C9, and CYP2D6. These genes affect the pharmacodynamics and pharmacokinetics of non-steroidal anti-inflammatory drugs and opioids. We examined the frequency of genetic variants to any of the medications we prescribed including celecoxib, hydrocodone, and tramadol. Patients were randomized to one of two groups: the control group received the standard postoperative pain regimen, and the study group received a customized regimen based on the pharmacogenetic results. For the first ten postoperative days, patients recorded pain scores, medication, and side effects. Genetic variants involving one or more medications in the multimodal pain protocol occurred in 13 of the 31 patients (42%). In total, eight patients (26%) had variants affecting more than one of the medications. For the 25 patients who recorded pain and medication logs, the mean pain levels and morphine equivalents (MEQs) consumed in the first ten days were higher in the control group than in the custom-guided group (p = 0.019 for pain and p = 0.655 for MEQ). Overall, 42% of patients had a variant involving one of the pain medications prescribed in our perioperative pain program for TKA. Ongoing research will help determine if using these data to modify a patient’s medication will improve outcomes.

May 2020

A Lower Threshold for Revision of Aseptic Unicompartmental vs Total Knee Arthroplasty
Johnson WB Jr, Engh CA Jr, Parks NL, Hamilton WG, Ho H, Fricka KB

It has been hypothesized that a unicompartmental knee arthroplasty (UKA) is more likely to be evised than a total knee arthroplasty (TKA) because conversion surgery to a primary TKA is a less complicated procedure. The purpose of this study was to determine if there is a lower threshold for revising a UKA compared with TKA based on Oxford Knee Scores (OKSs) and range of movement (ROM) at the time of revision. We retrospectively reviewed 619 aseptic revision cases performed between December 1998 and October 2018. This included 138 UKAs that underwent conversion to TKA and 481 initial TKA revisions. Age, body mass index (BMI), time in situ, OKS, and ROM were available for all patients. There were no differences between the two groups based on demographics or time to revision. The top reasons for aseptic TKA revision were loosening in 212 (44%), instability in 88 (18%), and wear in 69 (14%). UKA revision diagnoses were primarily for loosening in 50 (36%), progression of osteoarthritis (OA) in 50 (36%), and wear in 17 (12%). Out of a maximum 48 points, the mean OKS of the UKAs before revision was 23 (SD 9.3), which was significantly higher than the TKAs at 19.2 (SD 9.8; p < 0.001). UKA patients scored statistically better on nine of the 12 individual OKS questions. The UKA cases also had a larger pre-revision mean ROM (114°, SD 14.3°) than TKAs (98°, SD 25°) ; p < 0.001). At revision, the mean UKA OKSs and ROM were significantly better than those of TKA cases. This study suggests that at our institution there is a difference in preoperative OKS between UKA and TKA at the time of revision, demonstrating a revision bias.

May 2020

Nonsteroidal Anti-Inflammatory Drugs in Total Joint Arthroplasty: The Clinical Practice Guidelines of the American Association of Hip and Knee Surgeons, American Society of Regional Anesthesia and Pain Medicine, American Academy of Orthopaedic Surgeons, Hip Society, and Knee Society
Fillingham YA, Hannon CP, Roberts KC, AAHKS Anesthesia & Analgesia Clinical Practice Guideline Workgroup, Hamilton WG, Della Valle CJ

The American Association of Hip and Knee Surgeons (AAHKS), The American Academy of Orthopaedic Surgeons (AAOS), The Hip Society, The Knee Society and The American Society of Regional Anesthesia and Pain Medicine have worked together to develop evidence-based guidelines on the use of nonsteroidal anti-inflammatory drugs (NSAIDs) in primary total joint arthroplasty (TJA). The purpose of these guidelines is to improve the treatment of orthopedic surgical patients and reduce practice variation by promoting a multidisciplinary evidenced-based approach on the use of NSAIDs following primary TJA.

May 2020

The Efficacy and Safety of Acetaminophen in Total Joint Arthroplasty: Systemic Review and Direct Meta-Analysis
Fillingham YA, Hannon CP, Erens GA, Mullen K, Casambre F, Visvabharathy V, Hamilton WG, Della Valle CJ

Oral and intravenous (IV) acetaminophen has become widely used perioperatively as part of a multi-modal pain management protocol for primary total joint arthroplasty (TJA). The purpose of our study is to evaluate the efficacy and safety of acetaminophen in support of the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Management. We searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials for studies published prior to September 2019 on acetaminophen in primary TJA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of acetaminophen. In total, 1287 publications were critically appraised yielding 17 publications representing the best available evidence for analysis. Oral and IV acetaminophen demonstrates the ability to safely reduce postoperative pain and opioid consumption during the inpatient hospital stay. No evidence was available to assess the efficacy and safety of oral acetaminophen after discharge. Moderate evidence supports the use of oral and IV acetaminophen as a non-opioid adjunct for pain management during the inpatient hospitalization. Strong evidence supports the safety of oral and IV acetaminophen when appropriately administered to patients undergoing primary TJA. Although there is lack of robust evidence for use of acetaminophen following discharge, it remains a low-cost and low-risk option as part of a multimodal pain regimen.

May 2020

The Efficacy and Safety of Nonsteroidal Anti-Inflammatory Drugs in Total Joint Arthroplasty: Systemic Review and Direct Meta-Analysis
Fillingham YA, Hannon CP, Roberts KC, Mullen K, Casambre F, Riley C, Hamilton WG, Della Valle CJ

Nonsteroidal anti-inflammatory drugs (NSAIDs) have become widely used to manage perioperative pain following total joint arthroplasty (TJA). The purpose of our study is to evaluate the efficacy and safety of NSAIDs in support of the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and American Society of Regional Anesthesia and Pain Management. Databases including MEDLINE, EMBASE, and the Cochrane Central Registry of Controlled Trials were searched for studies published prior to November 2018 on NSAIDs in TJA. Studies included after a systematic review evaluated through direct comparisons and/or meta-analysis, including qualitative and quantitative heterogeneity testing, to evaluate effectiveness and safety of NSAIDs. After critical appraisal of 2921 publications, 25 articles represented the best available evidence for inclusion in the analysis. Oral selective cyclooxygenase (COX)-2 and non-selective NSAIDs and intravenous ketorolac safely reduce postoperative pain and opioid consumption during the hospitalization for primary TJA. Administration of an oral selective COX-2 NSAID reduced postoperative opioid consumption after discharge from TKA. Strong evidence supports the use of an oral selective COX-2 or non-selective NSAID and intravenous ketorolac as adjunctive medications to manage postoperative pain during the hospitalization for TJA. Although no safety concerns were observed, prescribers need to remain vigilant when prescribing NSAIDs.

May 2020

The Efficacy and Safety of Opioids in Total Joint Arthroplasty: Systemic Review and Direct Meta-Analysis
Hannon CP, Fillingham YA, Nam D, Courtney PM, Curtin BM, Vigdorchik J, Mullen K, Casambre F, Riley C, Hamilton WG, Della Valle CJ

Opioids are frequently used to treat pain after total joint arthroplasty (TJA). The purpose of this study was to evaluate the efficacy and safety of opioids in primary TJA to support the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and the American Society of Regional Anesthesia and Pain Management. The MEDLINE, EMBASE, and Cochrane Central Register of controlled trials were searched for studies published before November 2018 on opioids in TJA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of opioids. Preoperative opioid use leads to increased opioid consumption and complications after TJA along with a higher risk of chronic opioid use and inferior patient-reported outcomes. Scheduled opioids administered preemptively, intraoperatively, or postoperatively reduce the need for additional opioids for breakthrough pain. Prescribing fewer opioid pills after discharge is associated with equivalent functional outcomes and decreased opioid consumption. Tramadol reduces postoperative opioid consumption but increases the risk of postoperative nausea, vomiting, dry mouth, and dizziness. Moderate evidence supports the use of opioids in TJA to reduce postoperative pain and opioid consumption. Opioids should be used cautiously as they may increase the risk of complications, such as respiratory depression and sedation, especially if combined with other central nervous system depressants or used in the elderly.

May 2020

Acetaminophen in Total Joint Arthroplasty: The Clinical Practice Guidelines of the American Association of Hip and Knee Surgeons, American Society of Regional Anesthesia and Pain Medicine, American Academy of Orthopaedic Surgeons, Hip Society, and Knee Society
Fillingham YA, Hannon CP, Erens GA, AAHKS Anesthesia & Analgesia Clinical Practice Guideline Workgroup, Hamilton WG, Della Valle CJ

The American Association of Hip and Knee Surgeons, The American Academy of Orthopaedic Surgeons (AAOS), The Hip Society, The Knee Society, and The American Society of Regional Anesthesia and Pain Medicine have worked together to develop evidence-based guidelines on the use of acetaminophen in primary total joint arthroplasty (TJA). The purpose of these guidelines is to improve the treatment of orthopedic surgical patients and reduce practice variation by promoting a multidisciplinary evidence-based approach on the use of acetaminophen following primary TJA.

May 2020

Opioids in Total Joint Arthroplasty: The Clinical Practice Guidelines of the American Association of Hip and Knee Surgeons, American Society of Regional Anesthesia and Pain Medicine, American Academy of Orthopaedic Surgeons, Hip Society, and Knee Society
Hannon CP, Fillingham YA, Nam D, Courtney PM, Curtin BM, Vigdorchik JM, Buvanendran A, Hamilton WG, Della Valle CJ, AAHKS Anesthesia & Analgesia Clinical Practice Guideline Workgroup

The American Association of Hip and Knee Surgeons, The American Academy of Orthopaedic Surgeons (AAOS), The Hip Society, The Knee Society, and The American Society of Regional Anesthesia and Pain Medicine worked together to develop evidence-based guidelines on the use of opioids in primary total joint arthroplasty (TJA). The purpose of these guidelines is to improve the treatment of orthopedic surgical patients and reduce practice variation by promoting a multidisciplinary evidence-based approach on the use of opioids following primary TJA.

May 2020

The Efficacy and Safety of Gabapentinoids in Total Joint Arthroplasty: Systemic Review and Direct Meta-Analysis
Hannon CP, Fillingham YA, Browne JA, Schemitsch EH, Mullen K, Casambre F, Visvabharathy V, Hamilton WG, Della Valle CJ

Gabapentinoids are commonly used as an adjunct to traditional pain management strategies after total joint arthroplasty (TJA). The purpose of this study is to evaluate the efficacy and safety of gabapentinoids in primary TJA to support the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and the American Society of Regional Anesthesia and Pain Management. The MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were searched for studies published prior to November 2018 on gabapentinoids in TJA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of gabapentinoids. In total, 384 publications were critically appraised to provide 13 high-quality studies regarded as the best available evidence for analysis. In the perioperative period prior to discharge, pregabalin reduces postoperative opioid consumption, but gabapentinoids do not reduce postoperative pain. After discharge, gabapentin does not reduce postoperative pain or opioid consumption, but pregabalin reduces both postoperative pain and opioid consumption. Moderate evidence supports the use of pregabalin in TJA to reduce postoperative pain and opioid consumption. Gabapentinoids should be used with caution, however, as they may lead to an increased risk of sedation and respiratory depression especially when combined with other central nervous system depressants such as opioids.

May 2020

Gabapentinoids in Total Joint Arthroplasty: The Clinical Practice Guidelines of the American Association of Hip and Knee Surgeons, American Society of Regional Anesthesia and Pain Medicine, American Academy of Orthopaedic Surgeons, Hip Society, and Knee Society
Hannon CP, Fillingham YA, Browne JA, Schemitsch EH, AAHKS Anesthesia & Analgesia Clinical Practice Guideline Workgroup, Buvanendran A, Hamilton WG, Della Valle CJ

The American Association of Hip and Knee Surgeons, The American Academy of Orthopaedic Surgeons (AAOS), The Hip Society, The Knee Society, and The American Society of Regional Anesthesia and Pain Medicine have worked together to develop evidence-based guidelines on the use of gabapentinoids in primary total joint arthroplasty (TJA). The purpose of these guidelines is to improve the treatment of orthopedic surgical patients and reduce practice variation by promoting a multidisciplinary evidence-based approach on the use of gabapentinoids following primary TJA.

May 2020

Multimodal Analgesia for Hip and Knee Arthroplasty: Eliminating Opioids as the Cornerstone of Postoperative Pain Management
Fillingham YA, Hannon CP, Buvanendran A, Hamilton WG, Della Valle CJ

In 1996, the campaign to help prevent under assessment and poor management of pain popularized the slogan, “pain as the 5th vital sign.” The basis of the campaign was to make healthcare workers place the same importance on pain assessment as the existing 4 vital signs. The campaign led to widespread adoption within the medical field. As a result, the United States Hospital Consumer Assessment of Healthcare Providers and Systems survey included the question “How often did the hospital or provider do everything in their power to control your pain?” This formally established a connection between the treatment of pain and the United States Hospital Consumer Assessment of Healthcare Providers and Systems survey used to facilitate reimbursement by the Centers for Medicare and Medicaid Services. The unintended consequence of the emphasis on pain assessment and treatment and reimbursement to healthcare systems may have contributed to the opioid epidemic in the United States. As a result, many medical specialties and regulatory bodies have withdrawn their support of the “pain as the 5th vital sign” campaign.

May 2020

Narcotic Consumption in Opioid Naïve Patients Undergoing Total Hip and Knee Arthroplasty
Dattilo JR, Cororaton AD, Gargiulo JM, McDonald JM III, Ho H, Hamilton WG

Total knee arthroplasty (TKA) is associated with increased risk of prolonged narcotic requirement compared to total hip arthroplasty (THA). This study aims to compare acute postoperative narcotic consumption between the 2 procedures and quantify amount of narcotics used by opioid prescribed. From October 2017 to August 2019, patients were surveyed at 4-week follow-up to determine amount and duration of opioids used and whether they continued to require narcotics. Among 1332 patients who self-identified as opioid naïve, 670 underwent THA and 662 underwent TKA. Descriptive analysis was performed based on data type. The total morphine equivalent dose (MED) used in the postoperative period was lower in THA than in TKA (143 ± 160 vs 259 ± 250 MED, P < .001). The duration of use was shorter, total amount of pills consumed was lower, and refill rates were less in THA compared to TKA regardless of which opioid was prescribed. A smaller proportion of patients required narcotics at 4-week follow-up in THA compared to TKA. A postoperative prescription of 45 pills of any one type of narcotic was sufficient for nearly 90% of THA patients, and 60 pills of any one type of narcotic was appropriate for over 75% of TKA patients. THA is associated with less total narcotic consumption, shorter duration of use, less refills, and lower likelihood of requiring narcotics at 4-week follow-up. Percentiles of total narcotics consumed are provided to promote judicious postoperative prescribing patterns, and one could consider further reducing narcotics when utilizing our protocol, particularly for THA patients.

May 2020

Does a “July Effect” Exist for Fellowship Training in Total Hip and Knee Arthroplasty?
Dattilo JR, Parks NL, Ho H, Hopper RH Jr, McAsey CJ, Hamilton WG

The hypothetical association between health-care errors and the transition of the medical academic year has been termed the “July effect.” Data supporting its existence are conflicting, particularly in orthopedic surgery, and prior studies have inappropriately grouped fellows with resident trainees. No studies to date have examined whether a training initiation effect exists among surgical fellows in adult reconstructive orthopedics. This is a level IV retrospective cohort study reviewing 15,650 primary hip and knee arthroplasties performed from 2006 to 2016 at a single institution. Forty arthroplasty fellows were trained during this 10-year period. Primary outcome measures included intraoperative complications, additional procedures, revisions, and nonoperative complications within 90 days of surgery. These complication rates were analyzed by quarter of academic year and by temporal progression through three-month fellowship rotations. There were no differences in intraoperative complication, revision, or nonoperative complication rates between any academic quarter. There was a single statistically lower rate of additional procedures in the third quarter (1.2%) than in the fourth quarter (1.8%, P = .04). The most common complication in this subset was wound dehiscence for patients undergoing hip arthroplasty and stiffness for patients undergoing knee arthroplasty. There was no difference in complication rates during the first, second, or third month as fellows progressed through a single rotation. This study does not support the existence of a training-initiation effect among fellows in adult hip and knee reconstruction. Graduated autonomy can be safely employed in a fellowship program without negatively impacting patient outcomes, ensuring the continued high-caliber training of future surgeons.

March 2020

Narcotic Consumption in Opioid Naïve Patients Undergoing Unicompartmental and Total Knee Arthroplasty
Dattilo JR, Cororaton AD, Gargiulo JM, McDonald JM III, Ho H, Hamilton WG

Total knee arthroplasty (TKA) is associated with increased risk of prolonged narcotic requirement compared to unicompartmental knee arthroplasty (UKA). The purpose of the current study is to compare acute postoperative narcotic consumption between the 2 procedures and quantify narcotic consumption. From October 2017 to August 2019 patients were surveyed for four weeks to determine the amount and duration of opioids consumed and requirement for continued narcotics. Among 976 opioid naïve patients, 314 (32%) underwent UKA and 662 (68%) underwent TKA. Patients were analyzed according to specific narcotic prescribed. Total morphine equivalent dose (MED), number of pills, duration, refill percentage, and usage percentage for 4 weeks were calculated for each procedure. MED used in the postoperative period was lower in patients undergoing UKA than TKA (200 ± 195 vs 259 ± 250 MED, P = .002). Total number of pills consumed and duration of use was less in UKA compared to TKA regardless of which opioid was prescribed. A smaller proportion of patients required narcotics for 4 weeks after UKA (32% vs 43%, P < .001), and fewer UKA patients required narcotic refills (14% vs 27%, P < .001). Sixty pills of any 1 type of narcotic was sufficient for 90% of UKA patients and over 75% of TKA patients. UKA is associated with less narcotic consumption, shorter duration of use, less refills, and lower likelihood of narcotic requirement for 4 weeks. We report narcotic consumption patterns for both procedures to aid surgeons in judicious postoperative prescribing.

February 2020

The Impact of Coronal Alignment on Revision in Medial Fixed-Bearing Unicompartmental Knee Arthroplasty
Slaven SE, Cody JP, Sershon RA, Ho H, Hopper RH Jr, Fricka KB

To better define the optimal alignment target for medial fixed-bearing unicompartmental knee arthroplasty (UKA), this study compares the postoperative mechanical alignment of well- functioning UKAs against 2 groups of failed UKAs, including revisions for progression of lateral compartment osteoarthritis (“Progression”) and revisions for aseptic loosening or subsidence (“Loosening”). From our prospective institutional database of 3351 medial fixed- bearing UKAs performed since 2000, we identified 37 UKAs revised for Progression and 61 UKAs revised for Loosening. Each of these revision cohorts was matched based on age at surgery, gender, body mass index, and postoperative range of motion with unrevised UKAs that had at least 10 years of follow-up and a Knee Society Score of 70 or greater without subtracting points for alignment (“Success” groups). Postoperative alignment was quantified by the hip-knee-ankle (HKA) angle measured on long-leg alignment radiographs. The mean HKA angle at 4-month follow-up for the Progression group was 0.3° ± 3.6° of valgus compared to 4.4° ± 2.6° of varus for the matched Success group (P < 0.001). For the Loosening group, the mean HKA angle was 6.1° ± 3.1° of varus versus 4.0° ± 2.7° of varus for the matched Success group (P < 0.001). Patients with well- functioning UKAs at 10 years exhibited mild varus mechanical alignment of approximately 4°, whereas patients revised for progression of osteoarthritis averaged more valgus and those revised for loosening or subsidence averaged more varus. The optimal mechanical alignment for medial fixed-bearing UKA survival with contemporary polyethylene is likely slight varus.

2019

December 2019

Outpatient Total Hip Arthroplasty Performed at an Ambulatory Surgery Center vs Hospital Outpatient Setting: Complications, Revisions, and Readmissions
Sershon RA, McDonald JF III, Ho H, Goyal N, Hamilton WG

Outpatient total hip arthroplasty (THA) utilization continues to grow. Literature suggests outpatient THA may result in low rates of complications and readmission. There are no studies comparing safety profiles of THA performed at ambulatory surgery centers (ASC) vs hospital outpatient (HOP) settings. Prospectively collected data were reviewed on all patients who underwent THA from 2013 to 2018. ASC and HOP subgroups were compared, investigating difference in demographics, comorbidities, American Society of Anesthesiologists subgroups, all complications, revisions, emergency department (ED) visits, and readmissions within the first 90 days of surgery. An additional subgroup analysis of patients younger than 65 years was performed. Two surgeons performed 3063 THAs during the study period, including 965 outpatient cases (ASC = 335; HOP = 630). Thirty-seven (3.8%) complications occurred within 90 days. No differences were found between groups for 90-day complication rates (ASC = 13, 3.9%; HOP = 24, 3.8%; P = .48), revision rates (ASC = 0, 0%; HOP = 2, .3%; P = .30), all-cause reoperation rates (ASC = 1, 0.3%; HOP = 5, 0.8%; P = .35), ED visits (ASC = 3, 0.9%; HOP = 2, 0.3%; P = .23), or readmission rates (ASC = 2, 0.6%; HOP = 9, 1.4%; P = .25). THA can be safely performed in both ASC and HOP settings with low 90-day postoperative complication, revision, reoperation, ED visit, and readmission rates. Based on the populations studied, we identified no statistically significant differences in rates of complications between ASC and HOP groups.

November 2019

The Effects of Bundled Payment Programs for Hip and Knee Arthroplasty on Patient -Reported Outcomes
Finch DJ, Pellegrini VD Jr, Franklin PD, Magder LS, Pelt CE, Martin BI; Pepper Investigators (Fricka, KB)

Patient-reported outcomes are essential to demonstrate the value of hip and knee arthroplasty, a common target for payment reforms. We compare patient-reported global and condition-specific outcomes after hip and knee arthroplasty based on hospital participation in Medicare’s bundled payment programs. We performed a prospective observational study using the Comparative Effectiveness of Pulmonary Embolism Prevention after Hip and Knee Replacement trial. Differences in patient-reported outcomes through 6 months were compared between bundle and nonbundle hospitals using mixed-effects regression, controlling for baseline patient characteristics. Outcomes were the brief Knee Injury and Osteoarthritis Outcomes Score or the brief Hip Disability and Osteoarthritis Outcomes Score, the Patient-Reported Outcomes Measurement Information System Physical Health Score, and the Numeric Pain Rating Scale, measures of joint function, overall health, and pain, respectively. Relative to nonbundled hospitals, arthroplasty patients at bundled hospitals had slightly lower improvement in Knee Injury and Osteoarthritis Outcomes Score (-1.8 point relative difference at 6 months; 95% confidence interval -3.2 to -0.4; P = .011) and Hip Disability and Osteoarthritis Outcomes Score (-2.3 point relative difference at 6 months; 95% confidence interval -4.0 to -0.5; P = .010). However, these effects were small, and the proportions of patients who achieved a minimum clinically important difference were similar. Preoperative to postoperative change in the Patient-Reported Outcomes Measurement Information System Physical Health Score and Numeric Pain Rating Scale demonstrated a similar pattern of slightly worse outcomes at bundled hospitals with similar rates of achieving a minimum clinically important difference. Patients receiving care at hospitals participating in Medicare’s bundled payment programs do not have meaningfully worse improvements in patient-reported measures of function, health, or pain after hip or knee arthroplasty.

November 2019

The Effects of Bundled Payment Programs for Hip and Knee Arthroplasty on Patient-Reported Outcomes
Finch DJ, Pellegrini VD Jr, Franklin PD, Magder LS, Pelt CE, Martin BI; Pepper Investigators (Fricka, KB)

October 2019

Bundled Payments for Care Improvement: Health System Experience with Lower Extremity Joint Replacement at Higher and Lower Volume Hospitals
McAsey CJ, Johnson EM, Hopper RH Jr, Engh CA Jr

The Bundled Payments for Care Improvement (BPCI) initiative was introduced in 2013 to reduce Medicare healthcare costs while preserving or enhancing quality. We examined data from a metropolitan healthcare system comprised of 1 higher volume hospital and 4 lower volume hospitals that voluntarily elected to participate in the BPCI Major Joint Replacement of the Lower Extremity Model 2, beginning July 1, 2015. Stratifying the data by hospital volume, we determined how costs changed during the 16-month period when all 5 hospitals participated compared to the 1-year period preceding BPCI participation, where savings were achieved, and how the hospitals were rewarded. The Medicare data included the 90-day target for each episode and actual part A and part B spending for the anchor hospitalization plus all post-acute payments including inpatient rehabilitation, skilled nursing, home health, outpatient physical therapy, and hospital readmissions. The mean episode of care cost decreased by 11.1% (from $21,324 to $18,953) at the higher volume hospitals and by 8.3% (from $25,724 to $23,584) at the lower volume hospitals during BPCI participation compared to the preceding year. The savings were achieved by reducing the use of inpatient rehabilitation, shortening the length of stay at skilled nursing facilities, and decreasing readmission rates. Although the higher volume hospital achieved an increased mean savings of $230 per episode compared to the lower volume hospitals ($2371 vs $2141), it was penalized $490 per episode after reconciling the actual Medicare expenditures with the BPCI targets while the lower volume hospitals received a mean reward of $315 per episode. The BPCI initiative decreased costs and readmissions within our healthcare system. Despite substantial savings compared to the preceding year, the higher volume hospital’s low target derived from its 2009-2012 baseline costs was not achieved which resulted in a penalty and led it to withdraw from the BPCI initiative in October 2016.

October 2019

Periprosthetic Fracture Following Partial Knee Arthroplasty
Brown NM, Engh G, Fricka K

Partial knee arthroplasty is a procedure with long-term successful outcomes. However, there are several potential complications including retained cement fragments, bearing dislocation, infection, component loosening, medial collateral ligament injury, and overcorrection, leading to progressive arthritis. Periprosthetic fracture is an uncommon complication, with multiple reports showing an incidence of less than 1%. Hence, there are no established algorithms to guide treatment. A consecutive series of 2,464 patients who underwent partial knee arthroplasty between January 2009 and April 2017 was reviewed. We identified 16 patients with early periprosthetic fracture, with an incidence of 0.6%. All of these were tibial fractures, which occurred at a mean of 35 days postoperatively. There were 5 males and 11 females, with an average age of 70 years at the time of surgery. Average follow-up was 62 months. Two patients had contralateral compartment insufficiency fractures that were successfully treated nonoperatively, five patients immediately underwent total knee arthroplasty (TKA), and nine patients underwent open reduction internal fixation (ORIF). Two of these cases had a failed ORIF and required conversion to TKA. Seven patients were successfully treated with a medial buttress plate in compression. Average Knee Society Score at final follow-up was 81, and average flexion was 115 degrees, with no patients having greater than 5-degree flexion contracture. Periprosthetic fracture following partial knee arthroplasty resulted in a high rate of conversion TKA. However, ORIF in select patients resulted in fracture healing and retention of the partial knee replacement. All patients were successfully treated with low complication rates, excellent range of motion, and acceptable knee scores at final follow-up.

October 2019

Patient-Reported Outcomes Following Total Hip Arthroplasty: A Multicenter Comparison Based on Surgical Approaches
Finch DJ, Pellegrini VD Jr, Franklin PD, Magder LS, Pelt CE, Martin BI; Pepper Investigators (Fricka, KB)

Comparisons of patient-reported outcomes (PROs) based on surgical approach for total hip arthroplasty (THA) in the United States are limited to series from single surgeons or institutions. Using prospective data from a large, multicenter study, we compare preoperative to postoperative changes in PROs between posterior, transgluteal, and anterior surgical approaches to THA. Patient-reported function, global health, and pain were systematically collected preoperatively and at 1, 3, and 6 months postoperatively from patients undergoing primary THA at 26 sites participating in the Comparative Effectiveness of Pulmonary Embolism Prevention After Hip and Knee Replacement (ClinicalTrials.gov: NCT02810704). Outcomes consisted of the brief Hip disability and Osteoarthritis Outcome Score, the Patient-Reported Outcomes Measurement Information System Physical Health score, and the Numeric Pain Rating Scale. Operative approaches were grouped by surgical plane relative to the abductor musculature as being either anterior, transgluteal, or posterior. Between 12/12/2016 and 08/31/2019, outcomes from 3018 eligible participants were examined. At 1 month, the transgluteal cohort had a 2.2-point lower improvement in Hip disability and Osteoarthritis Outcomes Score (95% confidence interval, 0.40-4.06; P = .017) and a 1.3-point lower improvement in Patient-Reported Outcomes Measurement Information System Physical Health score (95% confidence interval, 0.48-2.04; P = .002) compared to posterior approaches. There was no significant difference in improvement between anterior and posterior approaches. At 3 and 6 months, no clinically significant differences in PRO improvement were observed between groups. PROs 6 months following THA dramatically improved regardless of the plane of surgical approach, suggesting that choice of surgical approach can be left to the discretion of surgeons and patients without fear of differential early outcomes.

October 2019

Recurrent Hemarthrosis Following Total Knee Arthroplasty
Held MB, Grosso MJ, Sarpong NO, Hamilton WG, Sista AK, Macauley W

Recurrent hemarthrosis is a treatable complication following total knee arthroplasty that can cause debilitating symptoms that can affect outcomes following a total knee arthroplasty. Making a diagnosis of recurrent hemarthrosis can be difficult, especially if providers are not familiar with this potential complication. The use of lower-extremity magnetic resonance angiography has been shown to be successful in diagnosing this potential complication. Current management strategies range from conservative therapy to targeted genicular artery embolization to arthroscopic and open synovectomy. Prompt identification and treatment of hemarthrosis following total knee arthroplasty are critical to avoid permanent limitations of range of motion that may jeopardize the postoperative outcome.

July 2019

Protocol Development for Outpatient Total Joint Arthroplasty
Hamilton WG

Converting from an inpatient to an outpatient total joint arthroplasty program is achievable, with a concerted effort from all members of the clinical team. This paper highlights key factors that allow for a successful implementation of an outpatient center. First, consistent messaging about patient safety is crucial in helping to assuage the patient’s concerns of getting an outpatient procedure, and to eliminate inpatient mentality. Next, earlier handout of prescriptions for medications, assisted devices, or web-based educational materials during preoperative preparations can also allow for a rapid home discharge. Finally, multimodal pain management before, during and after surgery can also pave the way for a smoother transition to daily living.

July 2019

To Cement or Not? Five-Year Results of a Prospective, Randomized Study Comparing Cemented vs Cementless Total Knee Arthroplasty
Fricka KB, McAsey CJ, Sritulanondha S

The optimal mode of fixation in total knee arthroplasty is a continuing subject of debate. Previously, we reported 2-year results for this prospective, randomized trial. Knee Society Scores, Oxford scores, and pain visual analog scales were collected pre-operatively and post -operatively. Minimum 5-year follow-up has been obtained with radiographic analysis for 85 patients. Mean Knee Society Scores and Oxford scores and patient-reported outcomes were similar in both groups. Each group had 1 additional revision, but neither was related to implant fixation. Survivorship with revision as an endpoint was equivalent (95.9% and 95.3%, P = .98). There was no significant difference in radiolucencies observed between groups (P = .10), all were non-progressive. Cementless and cemented total knee arthroplasty had equivalent patient- reported outcomes and survivorship at midterm follow-up. Updates are planned at 10 and 15-year intervals to observe long-term modes of failure between these 2 methods of fixation.

January 2019

A Prospective, Randomized Study of Surgical Positioning Software Shows Improved Cup Placement in Total Hip Arthroplasty
Hamilton WG, Parks NL, McDonald JF III, Pfefferle KJ

Several technologies are available to assist surgeons with acetabular component positioning in total hip arthroplasty. The purpose of this study was to determine whether surgical positioning software would improve cup position compared with fluoroscopy. This prospective, randomized study compared 200 primary total hip arthroplasty cups placed with and without surgical positioning software. All cases were performed by a single surgeon using the direct anterior approach with fluoroscopy. The target abduction and anteversion angles were set at 40° and 20°, respectively, and measured postoperatively. Cup placement time, total fluoroscopy time, and cup position were compared between groups. Mean abduction was 40.4° (range, 32.7°−49.0°) in the software group compared with 42.3° (range, 33.7°−51.1°) in the control group. The cups placed using software were significantly closer to the target abduction angle (P<.001) with fewer outliers. Mean anteversion was 20.8° (range, 11.2°−31.7°) in the software group compared with 21.8° (range, 11.3°−34.3°) in the control group (P=.063). Eighty-seven percent of cups in the software group fell within 5° of the abduction target, compared with only 68% in the control group (P<.01). Cup placement took longer in the software group (7:04 minutes vs 4:58 minutes, P<.001), and 2 seconds more total fluoroscopy time was used in that group as well (12.9 seconds vs 11.1 seconds, P<.001). The software improved both the accuracy and the precision of cup placement, with only modest increases in surgical time and fluoroscopy time.

January 2019

CORR Insights Commentary: Radiostereometric Analysis Permits In Vivo Measurement of Very Small Levels of Wear in TKA
Hopper RH Jr

Dr. Robert Hopper, the Director of Research at AORI, comments on the topic (and rates) of polyethylene wear in total knee arthroplasty.

2018

October 2018

Do Well-functioning THAs Retrieved at Autopsy Exhibit Evidence of Fretting and Corrosion?
Lange J, Wach A, Koch CN, Hopper RH Jr, Ho H, Engh CA Jr, Wright TM, Padgett DE

Our understanding of fretting and corrosion at head-neck junctions in modular THAs in vivo is based largely on the analysis of retrieved implants removed for various diagnoses. Little is known about the condition of head-neck tapers in well-functioning THAs. Regarding a cohort of well-functioning autopsy-retrieved modular THAs, we asked: (1) Does trunnion geometry or femoral head material affect the pull-off force of the femoral head? (2) Is there a relationship between trunnion damage and length of implantation time, head diameter, and neck length? (3) Does visual damage scoring accurately determine the presence or absence of corrosion on cobalt-chrome trunnions? Sixty-six femoral stems and engaged femoral heads were retrieved at autopsy from 53 patients at Anderson Orthopaedic Research Institute from 1998 to 2014. Ten stems were excluded for low stem design group size or insufficient head-stem clearance for pull-off testing, leaving a cohort of 56 THAs with a median implantation time of 10 years (range, 1-24 years). The femoral stems included three cobalt-chrome (CoCr) designs from a single manufacturer with either a 12/14 or 14/16 trunnion design (N = 36 and 20, respectively) mated with alumina or CoCr heads (N = 13 and 43, respectively). The force required to pull off the femoral heads was measured using a uniaxial load frame according to ASTM F2009-00. Mating surfaces were visually examined to assess the presence and severity of fretting and corrosion using a modified Goldberg scoring system. Three 12/14 trunnions of similar implantation lengths and varied damage scores were selected for imaging with a scanning electron microscope (SEM) and energy dispersive x-ray analysis (EDAX) to confirm the absence or presence of corrosion damage. No difference was seen in pull-off force between groups based on trunnion geometry and head material (median [range], alumina-12/14: 3127 [2320-6992] N, alumina-14/16: 2670 [1095-7919] N, CoCr-12/14: 2255 [1332-5939] N, CoCr-14/16: 2812 [1655-4246] N; P = 0.132). A positive correlation was found between damage score and length of implantation (P = 0.543, p < 0.001). However, no correlation between damage score and either head diameter or neck length was found (P = -0.012, P = 0.930 and P < 0.001, P = 0.995, respectively). In all, 39 of 56 specimens demonstrated no fretting or corrosion, and 16 specimens had mild damage scores. One specimen demonstrated severe corrosion without visual evidence of fretting. The presence of intergranular corrosion on this trunnion was determined by SEM imaging and EDAX. The absence of corrosion products on two trunnions with no observed damage was confirmed. This study found little evidence of fretting and corrosion in a cohort of well-functioning CoCr-CoCr and alumina-CoCr head-neck couples. Further studies are necessary to characterize fretting and corrosion at head-neck junctions of well-functioning implants of other designs and manufacturers. The results from this study suggest that patients with well-functioning THAs using polyethylene bearing surfaces with alumina or CoCr heads appear to be at low risk for trunnion corrosion for the specific CoCr alloy stems and trunnion geometries analyzed here.

September 2018

Periprosthetic Femur Fractures
Kinney MC, Engh CA Jr

As total hip arthroplasty rates continue to increase worldwide, so too does the prevalence of periprosthetic femur fractures. To properly manage these often-complex fractures, orthopaedic surgeons must have a systematic method for evaluating the patient as well as the fracture pattern. This review examines the demographic- and implant-specific factors that predispose patients to periprosthetic fractures with the goal of mitigating the risk of occurrence and improving patient counseling. Furthermore, with the development of new techniques and modern implants for the management of periprosthetic femur fractures, more tools are now available to address these complications and optimize patient outcomes.

September 2018

Simultaneous Bilateral Anterior Hips: Double Trouble-Opposes
Tauchen AJ, Hushmendy S, Parks NL, Pfefferle KJ, Hamilton WG

The purpose of this study was to compare a matched series of simultaneous bilateral anterior THA and unilateral anterior THA. 109 patients undergoing bilateral surgery were matched to a group of 218 patients undergoing unilateral surgery. In-hospital and 30-day complications were recorded. Bilateral patients did not experience an increased complication rate. Bilateral patients sustained greater blood loss with a higher likelihood of transfusion, but with attention to blood loss and hemoglobin, there was no higher incidence of complications in the bilateral group, and bilateral total hip arthroplasty was performed safely.

July 2018

The Lawrence D. Dorr Surgical Techniques & Technologies Award: “Running Two Rooms” Does Not Compromise Outcomes or Patient Safety in Joint Arthroplasty
Hamilton WG, Ho H, Parks NL, Strait AV, Hopper RH Jr, McDonald JF, Goyal N, Fricka KB, Engh CA Jr

Scrutiny from the federal government and the media regarding the safety of 1 surgeon doing cases in 2 operating rooms (ORs) on the same day, prompted us to examine our own institutional data. Over the past 11 years, surgeons at our facility have operated consecutively in 1 OR on a given day or used 2 alternating ORs. This study compares these cases with a focus on revisions and complications in both groups. Six surgeons performed a total of 16,916 primary hip and knee arthroplasties from 2006-2016. 7002 cases (41%) were consecutive cases (CCs) and 9914 cases (59%) were overlapping cases (OCs). Intraoperative complications, component revisions, and postoperative complications within 90 days of surgery were compared between the CC and OC groups. There was no difference in intraoperative complication rates between the two groups (CC 1.6% vs. OC 1.7%, relative risk 1.082, 95% confidence interval 0.852 to 1.375, P = .52). There was no difference in 90-day component revision rates among the CC and OC groups (0.66% vs. 0.85% respectively, relative risk = 1.290, 95% confidence interval 0.901 to 1.845, P = .19). There was also no difference in 90-day complication rates among the CC and OC groups (1.33% vs. 1.45% respectively, relative risk = 1.094, 95% confidence interval 0.844 to 1.417, P = .54). This large study of a single institution with multiple surgeons over an 11-year period shows no compromise in patient safety or outcomes when comparing cases done in either consecutive or overlapping rooms.

June 2018

Operating Room Traffic in Total Joint Arthroplasty: Identifying Patterns and Training the Team to Keep the Door Shut
Hamilton WG, Balkam CB, Purcell RL, Parks NL, Holdsworth JE

Surgical site infections after joint arthroplasty are devastating complications and are influenced by patient, surgical, and operating room environmental factors. In an effort to reduce the incidence of door openings (DOs) during total joint arthroplasty cases, this prospective observational study consisted of 3 phases. Phase 1 determined the baseline incidence of DOs, followed by installation of a mechanical door counter (phase 2). Finally, an educational seminar was presented to all personnel (phase 3) regarding the implications frequent DOs have on patient and surgical outcomes. The average openings per case (OPC) for each of the 3 phases were 33.5, 34.2, and 27.7, respectively. There was a 17% reduction in OPC between phases 1 and 3 ( P = .02). There were no significant differences between knee and hip arthroplasty cases during the 3 phases ( P = .21, P = .46, and P = .81, respectively). There was a strong correlation between length of surgery and OPC, with a Pearson coefficient of r = 0.87 during phase 3. To account for differences in average operative time between phases, data were normalized for the length of surgery with the ratio of door openings per minute determined (0.36, 0.34, and 0.32 for each phase, respectively). We were able to show that simply monitoring door openings during joint arthroplasty was not effective in reducing the occurrences. However, after a novel educational seminar given to all personnel, we were able to significantly reduce the incidence of operating room door openings, reducing a potential risk factor for surgical site infections.

April 2018

Elimination of Preoperative Flexion Contracture as a Contraindication for Unicompartmental Knee Arthroplasty
Purcell RL, Cody JP, Ammeen DJ, Goyal N, Engh GA

Unicompartmental knee arthroplasty (UKA) is an effective alternative to total knee arthroplasty (TKA) for the management of unicondylar osteoarthritis. Historical contraindications limit patients’ eligibility for UKA. However, recent reports have suggested that some contraindications may not be absolute. This study evaluates preoperative flexion contracture with regard to UKA. This study was a retrospective review of 53 patients with preoperative flexion contracture between 11° and 20° who underwent fixed-bearing UKA and a matched cohort of 53 patients who underwent cruciate-retaining TKA. Preoperatively, the average flexion contracture was 13.8° in the UKA group and 14.1° in the TKA group (P = 0.42). Mean preoperative motion was greater in the patients treated with UKA (106°) than in those treated with TKA (97°; P < 0.001). Postoperatively, patients who underwent UKA had greater motion than patients who underwent TKA had (121° versus 113°; P < 0.01). Residual flexion contracture was greater in the UKA group (4.1°) than in the TKA group (2.1°; P = 0.02). The two groups demonstrated similar improvements in Knee Society clinical scores (P = 0.32). However, patients treated with UKA demonstrated higher Knee Society functional scores, compared with patients treated with TKA (86 versus 75; P = 0.03). Although residual flexion contracture was worse after UKA, this group had similar clinical improvement, greater postoperative motion, and greater function scores, compared with the matched TKA group. Preoperative flexion contracture >5° may not be an absolute contraindication to UKA. The contraindications to UKA regarding flexion contracture may not be as absolute as previously thought. Larger, prospective studies are needed to generalize these findings to a wider population.

March 2018

Is Outpatient Unicompartmental Knee Arthroplasty Safe to Perform at an Ambulatory Surgery Center? A Comparative Study of Early Post-Operative Complications
Cody JP, Pfefferle KJ, Ammeen DJ, Fricka KB

Unicompartmental knee arthroplasty (UKA) lends itself to the outpatient surgical setting. Prior literature has established a low rate of readmission and post-operative complications when performed in a hospital outpatient setting (HOP). To our knowledge, there have been no studies comparing complications of UKA performed at an ambulatory surgery center (ASC) and those in a HOP. We retrospectively reviewed all patients who underwent outpatient UKA by a single surgeon from 2012 to 2016. In all 569 outpatient UKAs were performed: 288 in the ASC group and 281 in the HOP group. We compared the groups with regard to all complications within the first 90 days after surgery. Thirty minor and major complications occurred within 90 days (5.3%). There was no difference in the overall complication rate between groups (ASC 12, 4.2% HOP 18, 6.4%) ( P = .26). Day of surgery admission occurred once in the HOP group (0.4%) and did not occur in the ASC group ( P = .49). There was 1 visit to the emergency department (ED) <24 hours from surgery in each group (ASC 0.3%, HOP 0.4%) ( P = 1.0). ED visits occurred within 7 days in 3 ASC cases (1.0%) and 4 HOP cases (1.4%) ( P = .72). Re-admissions in the first 90 days occurred in 5 ASC cases (1.7%) and 8 HOP cases (2.8%) ( P = .41). UKA at an ASC has a low early postoperative complication rate without increased risk of re-admission or ED evaluation when compared to UKAs performed at a HOP.

February 2018

Otto Aufranc Award-Crosslinking Reduces THA Wear, Osteolysis, and Revision Rates at 15-year Followup Compared with Noncrosslinked Polyethylene
Hopper RH Jr, Ho H, Sritulanondha S, Williams AC, Engh CA Jr

Do patients who underwent THA with XLPE liners demonstrate (1) a lower rate of revision for wear-related complications; (2) a reduced wear rate; and (3) a lower frequency of osteolysis compared with those with CPE liners? Crosslinked polyethylene (XLPE) liners used for primary THA have demonstrated lower wear rates than noncrosslinked, conventional polyethylene (CPE) liners through the first decade of clinical service. However, little high-quality evidence is currently available regarding the second decade performance of these implants and it remains uncertain whether the onset of osteolysis has simply been delayed or if the wear associated with XLPE liners will remain low enough that osteolysis will not occur. It is also unknown how the potential reductions in wear and osteolysis will influence long-term revision rates. This randomized study with followup into the second decade demonstrated reductions in revision, wear, and osteolysis associated with the use of XLPE. The low wear rates and absence of any mechanical failures among the XLPE liners at long-term followup affirm the durability of these components that did not incorporate antioxidants. Although osteolysis has not been eliminated, it occurs infrequently and has not caused any clinical problems to date.

February 2018

Long-term Bone Remodelling Around “Legendary” Cementless Femoral Stems
Riviere C, Grappiolo G, Engh CA Jr, Vidalain JP, Chen AF, Boehler N, Matta J, Vendittoli PA

Bone remodelling around a stem is an unavoidable long-term physiological process highly related to implant design. For some predisposed patients, it can lead to periprosthetic bone loss secondary to severe stress-shielding, which is thought to be detrimental by contributing to late loosening, late periprosthetic fracture, and thus rendering revision surgery more complicated. However, these concerns remain theoretical, since late loosening has yet to be documented among bone ingrowth cementless stems demonstrating periprosthetic bone loss associated with stress-shielding. Because none of the stems replicate the physiological load pattern on the proximal femur, each stem design is associated with a specific load pattern leading to specific adaptiv periprosthetic bone remodelling. In their daily practice, orthopaedic surgeons need to differentiate physiological long-term bone remodelling patterns from pathological conditions such as loosening, sepsis or osteolysis. To aid in that process, we decided to clarify the behaviour of the five most used femoral stems. In order to provide translational knowledge, we decided to gather the designers’ and experts’ knowledge and experience related to the design rationale and the long-term bone remodelling of the following femoral stems we deemed ‘legendary’ and still commonly used: Corail (Depuy); Taperloc (Biomet); AML (Depuy); Alloclassic (Zimmer); and CLS-Spotorno (Zimmer).

January 2018

Comparison of Wound Complications and Deep Infections With Direct Anterior and Posterior Approaches in Obese Hip Arthroplasty Patients
Purcell RL, Parks NL, Cody JP, Hamilton WG

The purpose of this study was to compare the posterior approach (PA) with the direct anterior approach (DAA) among obese and nonobese total hip arthroplasty patients to determine if obese DAA patients have a higher risk of infection or wound complications compared with obese PA patients. We retrospectively evaluated 4651 primary total hip cases performed via anterior approach or PA between 2009 and 2015. Patients were divided into 4 study groups based on approach and body mass index (BMI): (1) DAA <35 kg/m 2, (2) DAA ≥35 kg/m 2, (3) PA <35 kg/m 2, and (4) PA ≥35 kg/m 2. Infection rates and wound complications were compared. The rate of deep infection in groups 1 and 3 (nonobese anterior vs posterior) was 0.28% and 0.36%, respectively (P = .783); and in groups 2 and 4 (obese anterior vs posterior) was 2.35% and 2.7%, respectively (P = .80). The rate of wound complications between groups 1 and 3 (nonobese) was 1.0% and 0.3%, respectively (P = .005). Between groups 2 and 4 (obese), the rates of complications were 1.7% and 1.4%, respectively (P = 1.0). There was no difference in reoperation rates for wounds between groups 1 and 3 or between groups 2 and 4 (P = .217, P = .449). In the largest available series, there was no difference in deep infection rates between the 2 approaches. In the subset of obese patients with BMI ≥35 kg/m 2, there was no increased risk of deep infection or wound complications in DAA patients compared with PA patients. However, anterior hip cases experienced higher rates of superficial wound complications compared with posterior cases across all BMIs.

2017

September 2017

Introduction
Hamilton WG

The introduction statement for Seminars in Arthroplasty

Read more: Seminars in Arthroplasty, Dec 2017;28(4);193.

November 2017

Intraoperative Fluoroscopy with a Direct Anterior Approach Reduces Variation in Acetabular Cup Abduction Angle
Goodman GP, Goyal N, Parks NL, Hopper RH Jr, Hamilton WG

The purpose of this study was to compare acetabular cup position for 2 cohorts of total hip arthroplasty (THA) patients who had a direct anterior approach. 100 THA cases were performed with an anterior approach using intraoperative fluoroscopy (IF) to aid in cup positioning. Another group of 100 cases underwent THA with an anterior approach without the use of any fluoroscopy. Postoperative abduction and anteversion angles were measured using Martell’s hip analysis software. Mean abduction angle was 43.2° (standard deviation (SD) = 4.5°) for the IF group versus 37.5°(SD = 7.4°) for cases without IF (p<0.001). 18% more cases with IF fell within the Lewinnek safe zone (p<0.001); however, a similar number of cases had over 50° of abduction. The mean anteversion angles of the two groups were also significantly different (IF 21.8° vs. 24.9°) (p<0.01). There was significantly less variation in cup position among the cases using IF with regards to abduction.

October 2017

Perioperative Pain Management and Anesthesia: A Critical Component to Rapid Recovery Total Joint Arthroplasty
Russo MW, Parks NL, Hamilton WG

Multimodal pain management has become the standard of care following total hip and knee replacement. The advantages include decreasing opioid consumption and its associated side effects, facilitating earlier mobilization, and faster return to function. An effective rapid recovery protocol includes the use of multiple different types of medications targeting each area of the pain pathway, preemptive analgesia, regional nerve blockade, and local infiltration analgesia.

September 2017

Comparative Incidence of Patellofemoral Complications Between Two Total Knee Systems in a Multi-Center, Prospective Clinical Study
Toomey SD, Daccach J, Shah J, Himden S. Lesko J, Hamilton WG

Cumulative incidence rates (CIRs) of patellofemoral complications (PCCs) and patellofemoral symptomatic crepitus (SC) using a new knee system-total knee arthroplasty (NEW-TKA) were compared with those of a currently available product-total knee arthroplasty (CA-TKA). Twenty-two investigators prospectively enrolled 704 patients into a study using CA-TKA; 364 received a posterior-stabilized configuration. Twenty-three investigators (19 from the CA-TKA study) enrolled 1138 patients with NEW-TKA; 584 received a posterior-stabilized configuration. CIRs were estimated with Kaplan-Meier methods. CA-TKA had 32 PCCs (6.15% CIR at 1 year and 8.26% at 2 years). NEW-TKA had 19 PCCs (3.15% CIR at 1 year and 4.11% at 2 years). CA-TKA had 15 SCs, 12 before 2 years (CIR = 3.67%); NEW-TKA had 5 SCs before 2 years (CIR = 1.21%). NEW-TKA had a statistically lower CIR of overall PCC and SC (log-rank P values = .018 for PCC and .017 for SC). Interim 1- and 2-year CIRs of PCC and SC in NEW-TKA were less than half of those for CA-TKA, which is a promising trend for this new implant.

July 2017

Lumbar Chance Fracture after Anterior Total Hip Arthroplasty
Pitta M, Wallach C, Bauk C, Hamilton WG

This report describes a patient with ankylosing spondylitis (AS) who underwent total hip arthroplasty (THA) by the direct anterior approach and sustained a L4-5 extension fracture dislocation with neural deficits. A magnetic resonance imaging revealed an epidural hematoma at the site of the fracture causing critical stenosis. The patient was taken to the operating room for a L3-S1 posterior decompression with L2-pelvis posterior spinal fusion. AS and diffuse idiopathic skeletal hyperostosis create a stiff spine that predisposes to fractures because of the larger moment arms experienced than normal spines. The arthroplasty surgeon performing THA should be aware and take precautions to reduce stress on the spine.

June 2017

Patellar Cut and Composite Thickness: The Influence on Postoperative Motion and Complications in Total Knee Arthroplasty
Hamilton WG, Ammeen DJ, Parks NL, Goyal N, Engh GA, Engh CA Jr

Little data exist on the influence of patellar thickness on postoperative motion or complications after total knee arthroplasty (TKA). This study addresses the following questions: Is postoperative motion influenced by change in composite patellar thickness? Is change in patellar thickness associated with more complications? And do more complications occur in the knees with a patellar bone remnant (<12 mm) and a native patellar thickness <18 mm?

June 2017

Problems and Solutions of the Extensor Mechanism
Russo MW, Parks NL, Hamilton WG, Engh CA Jr

Disruption of the extensor mechanism in a total knee patient is a devastating complication. This article focuses on prevalence, diagnosis, and treatment of a quadriceps tendon tear, patellar fracture, and patellar tendon rupture. Non-surgical management remains the standard of care in patients with a limited extensor lag. Reconstruction with an augment in more severe cases requires rigid fixation, coverage with host tissue, tensioning the augment material, and prolonged postoperative bracing in full extension. Patients continue to exhibit a high rate of complications following this uncommon and dire problem, so understanding the surgical risks and options is crucial.

March 2017

Outpatient Lower Extremity Total Joint Arthroplasty: Where Are We Heading
Banerjee S, Hamilton WG, Khanuja HS, Roberts JT

Surgeons have used a variety of approaches—strict patient selection, preoperative counseling, preemptive analgesia with anti-emetics, multimodal perioperative analgesic protocols that include adductor canal peripheral nerve blocks, wound infiltration with local anesthetics, less invasive surgical techniques, blood management with tranexamic acid, and completion of surgery by mid-morning or early afternoon—to enhance postoperative recovery, permit adjustment of medications, and allow timely discharge. Despite the appeal of outpatient arthroplasty, outcomes must be analyzed prior to its universal implementation in this era of cost reduction and savings and delivery of quality health care. The authors studied the outpatient total joint landscape, and reported their findings.

February 2017

Commentary-No Smoking Allowed: Is the Operating Room the Next Place that Smoking Patients Undergoing Total Joint Arthroplasty Will Be Banned?
Hamilton WG

Smoking has previously been identified to be a substantial health risk outside of the frame of total joint arthroplasty. Dr. Hamilton comments on a recently published article, “Smoking Increases the Rate of Reoperation for Infection within 90 Days After Primary Total Joint Arthroplasty”, which attempts to answer the question: how does smoking influence the outcomes of total joint arthroplasty?

2016

“As a surgeon-scientist, I enjoy the study of hip and knee replacements. I enjoy research because it allows me to study what I produce and makes me critically think about ways I can improve hip and knee replacements, it allows me to learn what works and what may not work as well.”

Dr. Kevin B Fricka, MD, Clinical Investigator

December 2016

The Anterior Approach: Better, Faster, and Cheaper
Tauchen AJ, Hamilton WG

Total hip arthroplasty is among the most common procedures performed by orthopaedic surgeons and there are many different surgical approaches that can be used. The direct anterior approach offers numerous benefits when compared to other surgical approaches. Some of these include an inter-muscular plane that avoids violating the abductors, minimal soft-tissue disruption, easy use of fluoroscopy with resultant improved component positioning, earlier functional recovery, and potential cost savings. While the procedure does have a learning curve and takes time to master, it is a safe approach for total hip arthroplasty that yields excellent clinical outcomes.

October 2016

Is The Anterior Approach Safe? Early Complication Rate Associated with 5090 Consecutive Primary Total Hip Arthroplasty Procedures Performed Using the Anterior Approach
Barnett SL, Peters DJ, Hamilton WG, Ziran NM, Gorab RS, Matt JM

Few publications have raised concern with the safety of the anterior approach (AA) to total hip arthroplasty (THA). The purpose of this study is to report the early complications with AA THA in a combined, multicenter patient population from three different institutions. This large multicenter study of consecutive AA THAs demonstrates an acceptable risk profile within the first 90 days after surgery.

October 2016

CORR Insights Commentary on Dual-Mobility or Constrained Liners Are More Effective Than Preoperative Bariatric Surgery in Prevention of THA Dislocation
Hamilton WG

Dr. Hamilton reviews a recently published paper, “Dual-mobility or Constrained Liners Are More Effective Than Preoperative Bariatric Surgery in Prevention of THA Dislocation”, and comments on the obesity epidemic and implications for total hip arthroplasty. In the commentary Dr. Hamilton identifies where we are in handling the crisis, where we need to go to tackle the challenges, and how we get there by laying out the steps that the orthopaedic community can use to reach our goals.

2016 Otto Aufranc Award

A Multi-Center, Prospective, Randomized Study of Outpatient versus Inpatient Total Hip Arthroplasty
Goyal N, Padgett SE, Chen AF, Tan TL, Kheir MM, Hopper, RH Jr, Hamilton WG, Hozack WJ.

This award winning study found hip replacement surgery just as satisfying for outpatients as for those patients staying a minimum of one night in the hospital. Dr. Nitin Goyal, and Dr. William Hamilton of AORI and colleagues from The Rothman Institute in Philadelphia, compared patient’s overall satisfaction with their hip replacement and their next day pain levels. Over two hundred randomly chosen patients were assigned to the either go home the same day or stay at least one night. The study also compared the number of follow up calls, doctor visits and post-surgical problems. Patients who went home the same day experienced slightly higher pain levels on the day after surgery compared to those who had at least one-night hospital stay. But the outpatients had a higher overall satisfaction with their surgery. Neither group exceeded the other in calls to the doctor or follow-up issues. The results of this study suggest outpatient total hip replacements work well for some patients.

March 28, 2016

Clinical Faceoff: Where Are We Going With Femoral Stem Fixation in THA?
Moskal JT, Capps SG, Engh CA Jr, Troelsen A.

Dr. Andy Engh of AORI, Alexandria, VA, and Dr. Anders Troelsen of Dept. of Orthopaedic Surgery, Copenhagen University Hospital alternately discuss the different trends in femoral stem fixation comparing the various methods of fixation in the US and Europe. Dr. Andy Engh states research shows cementless femoral implants are more durable for younger total hip replacement patients while cemented implants seem to work better with less fractures in older patients. Dr. Andy also remarks about the fact that North American doctors are generally not teaching how to cement so the practice is being used less. Dr. Anders suggested that the use of cement is still more common in Europe and that the practice of doing so needs to continue to be taught to the new generations of clinicians.

March 26, 2016

Severely Obese Patients Have a Higher Risk of Infection After Direct Anterior Approach Total Hip Arthroplasty.
Purcell RL, Parks NL, Gargiulo JM and Hamilton WG

Anderson Orthopaedic Research Institute’s clinical and scientific investigators: Dr. Rick Purcell, Nancy Parks, Jeanine Gargiulo and Dr. Bill Hamilton, reported that obese patients with a Body Mass Index of greater than 35, (≥35kg/m2), are at a substantially increased risk for a postoperative infection warranting revision surgery when the anterior surgical approach is used. This is likely due to the deep abdominal folds overlaying the incision. The investigators suggest comparative studies should be done using other surgical approaches with obese individuals to determine if the infections were primarily due to the approach or if significant increase in body mass increases overall risk of infections in hip patients.

February 2016

No Difference in Reoperations at 2 Years Between Ceramic-on-metal and Metal-on-metal THA: A Randomized Trial
Ench CA Jr, Sritulanondha S, Korczak A, Whalen TD, Naudie DDR, McCalden, RW, MacDonald SJ.

Anderson Orthopaedic Research Institute investigators and fellow collaborators from Division of Orthopaedic Surgery, Joint Replacement Institute, London Health Sciences Centre, London, Ontario, Canada, participated together in a prospective randomized trial comparing Ceramic-on-metal, (CoM), with Metal-on-metal, (MoM), bearings, the adjoined surfaces between the ball replacement on the top of the femur, and the cup insertion into the socket joint, or the acetabulum. Three hundred and ninety patients were enrolled in the trial at 11 different centers. Of the 390, 194 received ceramic-on-metal bearing surfaces while 196 received metal-on-metal bearings in their hip replacements. The short term follow-up for both groups showed successful performance of the hip implants. However, while the MoM group had a higher level of metal ions, the researchers decided that the CoM would need longer studies to see if it continued to perform well over time.

February 1, 2016

CORR Insights ® : Is There a Benefit to Modularity in ‘Simpler” Femoral Revisions?
Engh, CA

Dr. Andy Engh of AORI comments on the article with the same name by Huddleston and colleagues. In his commentary, Dr. Andy shares the importance of using the best method for each individual patient so the patient returns to maximal functional ability and best quality of life.

2015

“AORI has a database tracking hip and knee patients since the late 70's. Our surgeons operate on thousands of hip and knee joints a year. The high volume allows a much sooner observation of their outcomes.”

Henry Ho, Senior Project Director

August 2015

Short-term Results of Birmingham Hip Resurfacing in the United States.
Nam D, Nunley RM, Ruh EL, Engh CA Jr, Rogerson JS, Brooks PJ, Raterman SJ, Su EP, Barrack RL.

This group of collaborative investigators from 5 US centers including AORI were seeking information on success rates of Birmingham Hip Resurfacings done on 1271 patients between 2006-2008 in a 2 to 4 year follow up. Of the 1144 contacted either by phone or follow up appointments, only 16 patients needed revisions to total hip replacements. It appears the Birmingham Hip Resurfacing patients, 75% of whom were male were fairing as well as patients who had regular total hip replacements.

May 2015

Greater Trochanteric Fragmentation After Failed Metal-on-Metal Hip Arthroplasty.
Panichkul P, Fricka KB, Hopper RH Jr, Engh CA Jr.

The AORI investigators take a clinical and scientific look at bone loss of the greater trochanter in two patients after hip revision surgeries for failed metal-on-metal (MoM) hips. Both patients had revision surgeries replacing the failed metal-on-metal with polyethylene bearings. Yet 1-2 years later, both of these patients developed greater trochanteric fragmentation. This study warns that necrotic tissues may include bone as well as soft tissue. Orthopaedic doctors may wish to become mindful of this and pay attention for symptoms in potential hip revision patients.

2014

“Research is the eyesight for better patient care and the future of medicine.”

Neone Smith, Scientific Investigator

April 29, 2014

The functional assessment test: a method of evaluating improvement in function after knee arthroplasty.
Engh GA, Sheridan MJ, Ammeen DJ.

Dr. Jerry Engh and research colleagues developed an easily administered timed test called the Functional Assessment test to determine if knee replacement patients improved their daily activity skills. The test included standing, walking and climbing stairs. The researchers concluded the FA test would be practical in a clinical environment.

March 19, 2014

Metal ion levels after metal-on-metal total hip arthroplasty: a five-year, prospective randomized trial.
Engh CA Jr, MacDonald SJ, Sritulanondha S, Korczak A, Naudie D, Engh C.

Fellow investigators from Anderson Orthopaedic Research Institute in Alexandria, VA and London Health Sciences Centre-University Hospital Orthopaedics, Ontario Canada studied a randomized group of patients undergoing total hip arthroplasty. The 105 patients did not know which of three categories of implant they would receive. The three types of implants used were as follows: 28-mm metal-on-polyethylene, 28-mm metal-on-metal or 36-mm metal-on-metal. The U.S. Food and Drug Administration desired follow-up data for these after-market devices. Metal levels were tested in all patients. The outcome of the tests showed the metal-on-metal hip patients and particularly the 36-mm patients had higher levels of metal ions in their blood at the five-year follow up. The metal-on-polyethylene group had appreciably lower metal ions in their blood. The investigators indicate watching the metal-on-metal group closely.

2013

2013 OREF/CCJR Clinical Practice Award

Patient Specific Instruments do not Shorten Surgical Time: A Prospective, Randomized Trial
Hamilton WG, Parks NL, Saxena A.

AORI’s Dr. Bill Hamilton won the 2013 OREF/CCJR Clinical Practice Award for his research comparing the amount of time it took to perform total knee replacements using patient-specific instrumentation (PSI) compared to using traditional instrumentation (TI). The PSI group’s surgeries actually took an average of 4 minutes longer compared to the TI group. However, the TI surgeries required more instrument trays. In conclusion, surgery with patient specific instruments did not shorten the operation time.

2013 AAHKS Dorr Award

Do you have to remove a corroded femoral stem?
Goyal N, Ho H, Fricka KB, Engh CA Jr.

Drs Fricka, Goyal and Anderson, of AORI discuss leaving securely placed femoral stems in the bone even if some corrosion exists. This retrospective study looked at 86 retrieved femoral heads from metal-on-polyethylene total hip replacements. The heads were evaluated after they were replaced with new components in living, healthy patients. Out of the 86 patients only 7 needed hip re-revisions. None of the re-revisions were due to corrosion of the stem. Since corrosion of the stems did not create a need for additional surgery, the AORI researchers recommend leaving well-attached stems in place.

September 28, 2013

Radiographically measured total knee wear is constant and predicts failure.
Engh CA Jr, Collier MB, Hopper RH Jr, Hatten KM, Engh GA

Drs. Jerry and Andy Engh, high volume orthopaedic joint replacement surgeons, look at the wear of knee implants over 10 years of follow-up visits with their patients. Working together with the scientists at AORI, they found that wear of the prosthetic knees is constant over time in most cases. Compared to knees with lower rates, knees with higher wear rates are more likely to need revision at some point in the future.

2012

2012 Chitranjan Ranawat Award

Efficacy of Postoperative Intra-articular Analgesia Following Total Knee Arthroplasty: A Randomized, Double Blinded, Placebo-Controlled, Prospective Study.
Goyal N, McKenzie, J, Sharkey PF, Parvizi J, Hozack WJ, Austin MS.

Dr. Goyal, clinical investigator at AORI and colleagues from Thomas Jefferson University Hospital & The Rothman Institute in Philadelphia were awarded the Ranawat Award for this study on the effect of using pain pumps with bupivacaine, a local anesthesia, for post-operative patients having total knee replacements. They found that using a pain pump near the surgery area significantly decreased patients’ pain as well as their use of narcotics.

2011

2011 AAHKS Dorr Award

A Prospective, Randomized Study of Crosslinked and Non-Cross-linked Polyethylene for Total Hip Arthroplasty at 10-Year Follow-Up.
Engh CA Jr, Hopper RH Jr, Huynh C, Ho H, Sritulanondha S, Engh CA Sr.

Drs. Charles and Andy Engh and a team of AORI scientific investigators won the AAHKS Dorr award for this randomized study following up on patients with either cross-linked or non-cross-linked polyethylene liners in their total hip arthroplasties after ten years. The results show that the cross-linked liners had longer wear and fewer bone loss related problems.

2010

February 2010

Survivorship of a low-stiffness extensively porous-coated femoral stem at 10 years.
Hartzband MA, Glassman AH, Goldberg VM, Jordan LR, Crowninshield RD, Fricka KB.

Over one hundred patients were studied in follow up visits who had been a part of an original prospective study using a new femoral implant with greater flexibility and extra porous coating to determine how well the implants were serving the patients. In the 86 living patients who were followed this particular femoral implant was still yielding an excellent Harris Hip Score of 98 at the ten-year mark. The researchers suggest that this particular type of component has very good long term function and wear.

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