New Study from Hospital for Special Surgery Reveals Young, Active Patients Who Have Total Knee Replacements are Unlikely to Need Revision Surgery in their Lifetime

SAN DIEGO--(BUSINESS WIRE)--A 40-year study by Hospital for Special Surgery (HSS) researchers has found that active young adults who underwent total knee replacement were unlikely to require knee replacement revision in their lifetime, according to a new study shared today in a podium presentation at the American Academy of Orthopaedic Surgeons 2025 Annual Meeting.¹

“As an increasing number of younger adults in their 40s and 50s consider total knee replacement, many wonder how long knee implants last before requiring a revision procedure,” says William J. Long, MD, FRCSC, an HSS hip and knee surgeon and the senior author of the study. “The findings from our study—the largest and longest follow-up of patients under 55 undergoing total knee replacement—confirm that young patients can be confident their initial knee implants will allow them to pursue a high level of activity and more than likely last the rest of their lives.”

HSS orthopedic surgeons designed the longitudinal study to track outcomes for patients 55 years of age and younger who had total knee replacements between 1977 and 1992. During that period, they used knee prostheses known as the Insall-Burstein I and Insall-Burstein II—predecessors of implants used today that provide posterior stability. Both designs were conceived and developed at HSS. Previously, the investigators conducted patient follow-ups at 10, 25, and 30 years following surgery.

For this final report, Dr. Long and colleagues analyzed outcomes after 40 years for 81 patients aged 33 to 55 years. The analysis included 107 knees in total. Overall, 70% of patients in the study had no revision procedures in their lifetime. Patients were three to four times more likely to have passed away after 40 years than to have required a revision. Remarkably, among the 49 patients who received the original Insall-Burstein I prostheses, 80% did not have any revision surgeries.

“Considering that today's knee replacements have addressed the pitfalls leading to the majority of revisions for mechanical issues in Insall-Burstein I and Insall-Burstein II implants, these are very reassuring findings," says Dr. Long.

Dr. Long also examined six patients (eight knees) in person, and lead and presenting author Aaron Weinblatt, BA, contacted many more patients by phone. There were no signs of loosening nor were there any changes in symmetry or alignment of the original components. Additionally, patients reported an ongoing improved level of activity after surgery.

This was supported by patient-reported activity data collected for eight patients (10 knees) and measured using the Tegner Activity Scale (TAS). Before undergoing total knee replacement, the average TAS score was only 1.5, indicating they could work in a sedentary job and walk on uneven ground but not hike or backpack. At 40 years, their average TAS score was 2.7, indicating the ability to work in light labor occupations and participate in recreational activities such as swimming and walking in forests.

“Patients requiring a total knee replacement should not delay having surgery,” Dr. Long says. “Our study results highlight that those who undergo knee replacement sooner are more likely to maintain a high level of activity that contributes to a healthy, longer-term lifespan.”

Dr. Long adds that a previous HSS study published in 2014 at the 30-year follow-up showed that for the small percentage of patients who required revisions, the vast majority were doing well, with an average TAS score of 3.0, a good range of motion and no signs of loosening. ²

Authors: Aaron I. Weinblatt, BA, Victoria E. Bergstein, BA, Walter L. Taylor, MPhil, BS, Stephen Lyman, PhD, Felix C. Oettl, MD, W. Norman Scott, MD, FAAOS, William J. Long, MD, FRCSC.

Reference:

¹ Weinblatt AI, Bergstein VE, Taylor WL, Lyman S, Oettl FC, Scott WN, Long WJ. Total knee replacement in young, active patients: long-term follow-up and functional outcome: A final follow-up of previous report. Accessed February 10, 2025, at https://submissions.mirasmart.com/AAOS2025/Itinerary/PresentationDetail.aspx?evdid=2532

² Long WJ, Bryce CD, Hollenbeak CS, Benner RW, Scott WN. Total knee replacement in young, active patients: long-term follow-up and functional outcome: a concise follow-up of a previous report. J Bone Joint Surg Am. 2014 Sep 17;96(18):e159. Accessed February 19, 2025, at https://pubmed.ncbi.nlm.nih.gov/25232089/

About HSS

HSS is the world’s leading academic medical center focused on musculoskeletal health. At its core is Hospital for Special Surgery, nationally ranked No. 1 in orthopedics (for the 15th consecutive year), No. 3 in rheumatology by U.S. News & World Report (2024-2025), and the best pediatric orthopedic hospital in NY, NJ and CT by U.S. News & World Report “Best Children’s Hospitals” list (2024-2025). In a survey of medical professionals in more than 20 countries by Newsweek, HSS is ranked world #1 in orthopedics for a fifth consecutive year (2025). Founded in 1863, the Hospital has the lowest readmission rates in the nation for orthopedics, and among the lowest infection and complication rates. HSS was the first in New York State to receive Magnet Recognition for Excellence in Nursing Service from the American Nurses Credentialing Center five consecutive times. An affiliate of Weill Cornell Medical College, HSS has a main campus in New York City and facilities in New Jersey, Connecticut and in the Long Island and Westchester County regions of New York State, as well as in Florida. In addition to patient care, HSS leads the field in research, innovation and education. The HSS Research Institute comprises 20 laboratories and 300 staff members focused on leading the advancement of musculoskeletal health through prevention of degeneration, tissue repair and tissue regeneration. In addition, more than 200 HSS clinical investigators are working to improve patient outcomes through better ways to prevent, diagnose, and treat orthopedic, rheumatic and musculoskeletal diseases. The HSS Innovation Institute works to realize the potential of new drugs, therapeutics and devices. The HSS Education Institute is a trusted leader in advancing musculoskeletal knowledge and research for physicians, nurses, allied health professionals, academic trainees, and consumers in more than 165 countries. The institution is collaborating with medical centers and other organizations to advance the quality and value of musculoskeletal care and to make world-class HSS care more widely accessible nationally and internationally. www.hss.edu.