AORI's Role in Modern Total Joint Replacement
A Timeline of Change
Over the last century total joint replacements have gone from a vision to a well-established operation that dramatically improves millions of lives throughout the world each year. Below is a brief timeline of advances, with some of AORI's contribution in bold.
1890 Gluck performs first total hip replacement by putting an ivory ball on femoral neck.
1923 Forward leap: Smith-Petersen reconstructs femoral head with a molded glass cup. Cups shatter, but mold concept grows.
1930s Forward leap: Discovery that cobalt chrome is inert in human tissue.
1940 Dr. Otto Anderson & Mrs. Sara Watkins Engh start first Washington D.C.-area hospital for children crippled by polio.
1943 Moore and Bohlman use a 12-inch stem to replace the upper femur.
1943- Implant fixation remains a major hurdle for successful joint replacements.
(timeline continues below)
Since its inception in 1972, Anderson Orthopaedic Research Institute's (AORIís) studies have led to new insights concerning orthopaedic surgical practices, patient outcomes, and orthopaedic implants. (See the adjacent timeline.)
The benefits of such research was seen early in AORI's history by the development of the first FDA-approved, porous-coated, cementless hip implant. Anderson Clinic physician Dr. Charles Engh pioneered this implant in the United States to address the problem of durable implant fixation that caused early failures of hip implants in the 1970s (see About THR). Durable fixation was achieved with the new cementless implant by biological fixation, meaning that the patient's bone grew into the implant. Since then, AORI has thoroughly evaluated the outcomes of cementless total hip replacements in numerous studies.
Today, AORI's studies continue to shed light on the effectiveness of both hip and knee replacements. We share our findings in peer-review journals, orthopaedic text books, popular publications, videos, and through presentations.
AORI's research topics include the following subjects:
- Effectiveness of cementless hip implants
- Improving the longevity of hip and knee replacements
- Patient outcomes from new implant designs
- Treatment of challenging patient populations
- The effectiveness of different surgical techniques
- Recovery procedures after hip and knee arthroplasties.
This web site includes summaries and abstracts of recent publications. Papers on these topics can be requested through this web site by writing Research@aori.org.
1950s New Austin-Moore stem shows possibility of biologic fixation through bone ingrowth.
1955 Anderson Hospital becomes National Orthopaedic Hospital, one of the first U.S. orthopaedic hospitals. Serves workers with orthopaedic injuries.
1958 Forward leap: Sir John Charnley (UK) develops a cement that firmly fixes stems.
1961 J. Charnley finds a high-density plastic for low-friction for total hip arthroplasty (THA). His procedures set the stage for modern THA.
1960s THA emerges as successful procedure.
1970s Implant loosening remains number one problem. International research continues on biologic and cement fixation.
1972 Anderson Orthopaedic Research Institute (AORI) established to improve total joint arthroplasty.
1970s. AORI starts databases on hip and knee patient; first uses keypunch cards.
- Because of AORI's relationship with the Anderson Orthopaedic Clinic, we have developed unique resources that are invaluable to long-term research.
AORI resources include:
A computerized database of over 12,000 patients with hip and knee replacements. This database, the most extensive of its kind in the world, provides long-term clinical and functional data from which researchers can determine the effectiveness of treatments and implant designs.
Radiographic archives that make it possible to monitor the long-term progress of patients. X-rays of each of the Anderson Clinic's patients over the last 30 years are stored in our archives, making this one on the most comprehensive and valuable research resources for hip and knee replacements in the world.
A collection of postmortem-retrieved hip and knee implants. Again, this is one of the largest and most valuable collections of hip and knee implants in the world, AORI's retrieval collection provides invaluable insight to the actual performance of implants in patients. This collection is a living testimony to past patients who believed in the importance of orthopaedice research and who were dedicated to sharing the gift of pain-free movement they had received.
1977 Forward Leap: C.Engh Sr. (AORI) pioneers porous-coated implants in U.S.
1983 Knee revisions become easier with new modular knee implants. Metal platform for plastic insert gives greater support.
1992 C. Engh Sr. (AORI) wins John Charnley Award for study confirming that porous-coated implants are stable.
1996 AORI researchers win Otto Aufranc Award for findings on bone loss surrounding hip implants.
1997 AORI's long-term results of porous-coated stems show that 97% survive at 12 years.
1997 G.Engh wins Ranawat Award for study showing efficacy of bone grafts, using AORI's retrieval bank.
The Anderson Orthopaedic Research Institute (AORI) began in the late 1930s as one manís mission to improve the health of patients with musculoskeletal disorders.
AORI founder, the late Dr. Otto Anderson Engh, dedicated his career to addressing the great need for orthopaedic services in the Washington DC area. He began by starting a community clinic for crippled children. He later began the first area hospital for orthopaedics -- the National Hospital for Orthopaedics and Rehabilitation in Arlington -- and opened the Anderson Clinic in Arlington, Virginia.
Believing in the necessity of research to improve the art of orthopaedics, Dr. Otto started AORI in 1972. Today, his vision continues to grow, as Anderson Clinic physicians Ė his sons, Drs. Charles and Gerard Engh, his grandson, Dr. Charles Engh, Jr., and their colleague, Dr. James McAuley Ė and a Board of Directors guide the efforts of this not-for-profit institute.
1998 Coventry Award goes to AORI researchers for linking micromotion and implant wear in modular knee implants. Changes types of implants used at Anderson Clinic.
Late 1990s- orthopaedists around the United States working to develop minimally invasive procedures for total hip arthroplasty.
2000 About 560,000 hip and knee arthroplasties are performed each year in the U.S.
2000- AORI physicians G. Engh and J. McAuley begin using a new minimally invasive unicondylar knee implant developed with an international team.
2001 - AORI develops a template physicians can easily use in their offices to accurately diagnose hip implant wear.
2000-3- AORI focuses on ways to defeat the implant wear and osteolysis. Collaborates with another institution to develop a new CT program that improves diagnosis of pelvic osteolysis.
2003- AORI continues to search for ways to lengthen the longevity of hip and knee implants.
AORI appreciates the generosity of Anderson Clinic patients who have supported our research and, thus, the welfare of future patients. Their efforts include bequests to our implant retrieval program, volunteer work, and financial donations.
AORI's Implant Retrieval ProgramWith the understanding that their lives can impact AORI's research after their deaths, many Anderson Clinic patients have bequeathed their prosthetic devices to our institute. Because of these patients and families, AORI has an extensive collection of cementless hip and knee implants retrieved postmortem. AORI also collects implants that have been removed during revision surgeries because of infection or failure. These specimens are invaluable. They enable our researchers to determine the changes that take place to implants and to surrounding tissue while the implants are in place and to understand how various implants perform in various patients (young, old, those with rheumatoid arthritis, etc.)
The need for retrieved implants will continue as long as their is a need to improve joint replacements. We welcome all requests about how patients can support this program. Patients who wish to learn how they can participate in AORI's implant retrieval program are encouraged to call 703-619-4411. We are committed to making this program as unintrusive to grieving family members as possible.
All financial donations AORI are tax deductible.
For more information on the various ways to contribute to AORI, contact 703-619-4411 or Research@aori.org.