The meniscus is vital to the healthy functioning of the knee joint. Missing or damaged meniscus tissue can lead to the development of osteoarthritis. Our research informs meniscus allograft transplants (MATs) as a repair strategy to help prevent or delay knee replacement.
Total Patients Studied
MAT Procedures
Outcomes Tracked
Allograft Survival
The meniscus is a soft, fibrous cartilage that sits between the femur and tibia. In a healthy knee, it acts as a natural shock absorber, helping distribute force across the joint. When meniscus tissue is damaged or removed, that force is transmitted abnormally, leading to cartilage wear, pain, arthritis, and loss of activities.
Meniscus tears are often treated by trimming or removing the damaged tissue. This can relieve symptoms in the short term, but the loss of meniscus tissue accelerates the process of joint damage and the onset of osteoarthritis (OA), causing pain and making it increasingly difficult for people to remain active over time.
SRF research demonstrates that replacing all or part of a damaged or missing meniscus with allograft (donor) cartilage can help restore its function. Our long-term findings challenge the assumption that age, arthritis, or demanding athletic goals must bring an active life to an end.
Patients once considered outside the traditional limits of transplantation may now have an opportunity to preserve their natural knee and return to high-level activity.
Through our clinical research and leadership of the Meniscus Transplant Study Group, SRF brings together international expertise to advance the science of meniscus transplantation and move discoveries into clinical care.
SRF research demonstrated that meniscus allograft transplantation can be successful in patients over 50 with significant arthritis, expanding treatment options for patients who might otherwise proceed directly to knee replacement.
Meniscus allograft transplantation was traditionally indicated for patients under age 50 with limited arthritis. Older age and arthrosis (degenerative arthritis) were commonly viewed as contraindications, ruling many patients out for the procedure.
In a long-term study, SRF examined patients over 50 with arthritic knees who had previously been advised to undergo arthroplasty (knee replacement surgery). The findings showed that meniscus allografts, used in conjunction with arthroscopic biologic knee repair procedures, can:
Survive in arthritic knees
Improve pain and function
Delay artificial knee replacement
SRF research established that patients with moderate to severe articular cartilage damage can return to sporting activities after meniscus allograft transplantation, challenging the belief that advanced cartilage damage should rule out both the procedure and a return to sports.
Meniscus allograft transplantation had already been shown to reduce pain and improve function in patients with missing or irreparable menisci. However, there was limited evidence about whether active patients with severe articular cartilage damage could achieve similar outcomes and resume sporting activities.
In a longitudinal study of 49 patients, SRF found that meniscus allograft transplantation provided significant improvements in pain and function in the medium to long-term. The majority of patients achieved their goal of participating in sporting activities, and the transplant had an estimated mean survival time of 12.6 years. These findings supported meniscus allograft transplantation as a viable surgical option for active patients with severe cartilage damage and missing or irreparable menisci.
SRF research showed that height, weight, and sex can help predict meniscal dimensions, providing tissue banks and surgeons with a faster, more cost-effective method for matching donor tissue to transplant recipients.
Accurate sizing is important because a transplanted meniscus must closely match the recipient’s anatomy. Traditional sizing methods rely on radiographs or MRI and can be difficult to apply consistently.
SRF found that these simple anthropometric measurements were correlated with meniscal size. The findings established a practical approach that can streamline donor-recipient matching for meniscus allograft transplantation.
The Meniscus Transplant Study Group brings together orthopaedic surgeons, scientists, and veterinary surgeons from around the world to share research, advance surgical techniques, and strengthen the clinical practice of meniscus transplantation. SRF supports and leads this collaboration as part of its broader meniscus research program.
The 2026 MTSG meeting will be held on October 8 at the ICRS Summit in Porto, Portugal, with options to attend in person or virtually.
Click below to learn more.
SRF tracks the outcomes of all patients undergoing meniscus transplantation at The Stone Clinic, using this long-term data to inform the field while continuing to explore new approaches and research collaborations in meniscus regeneration and transplantation.
Meet real patients who benefited from advances developed through SRF meniscus research, preserving their natural joints while regaining function and returning to high-level activity. Watch their stories of recovery and the journey back to active living.
Shweta, an avid runner and triathlete, faced the heartbreaking possibility of never being able to run again after a devastating knee injury. Thanks to the articular cartilage paste graft procedure studied by the Stone Research Foundation, Shweta recovered and reclaimed the sport that fuels her spirit and creativity.
Surgical technique for medial meniscus allograft transplantation.
View Full DetailsStep-by-step lateral meniscus allograft transplantation technique.
View Full DetailsShowing 7 of 7 studies
Kevin R. Stone, Ann W. Walgenbach
Research Question: How can arthroscopic meniscal allografting be refined?
A technical note on the arthroscopic three-tunnel technique
Key Finding: The arthroscopic three tunnel technique for meniscal allografting enables accurate placement and stable fixation of medial and lateral allografts to the tibia at 3 sites.
Kevin R. Stone, Ann W. Walgenbach, Thomas J. Turek, Abhi Freyer, Martin D. Hill
Research Question: Can meniscus allografts survive and provide clinical benefit in knees with moderate to severe unicompartmental arthritis?
2-7 Year Prospective Study of 45 Patients with Moderate to Severe Arthritis Receiving a Meniscus Allograft Transplant
Key Finding: Meniscus allograft transplantation can reliably survive and improve symptoms in knees with advanced unicompartmental arthritis.
Kevin R. Stone, Abhi Freyer, Thomas J. Turek, Ann W. Walgenbach, Sonali Wadhwa, John V. Crues III
Research Question: Can demographic variables (i.e., height, weight, gender) serve as reliable, fast, and cost-effective predictors of meniscal dimensions for transplantation compared to traditional imaging-based sizing methods?
Pearson correlation between MRI-based meniscal sizing of 147 menisci in 111 patients to BMI and gender followed by a paired t test to stratify by BMI.
Key Finding: Height, weight, and gender are practical and easily obtained variables that correlate with tibial plateau width and meniscal size.
Kevin R. Stone, Ann W. Walgenbach, Abhi Freyer
Research Question: What lessons from the first 100 meniscus allograft transplants in arthritic knees can optimize patient outcomes and delay or avoid joint arthroplasty?
Book chapter detailing patient selection, surgical techniques, post-operative rehabilitation, and summary of published outcomes study results.
Key Finding: Meniscus allograft transplants can reliably survive and provide meaningful symptom improvement, even in arthritic joints.
Kevin R. Stone, Johnathan R. Pelsis, Wendy S. Adelson, Ann W. Walgenbach
Research Question: Can collagen meniscus implants be used to reconstruct areas of torn or damaged meniscus?
Monograph detailing use of collagen meniscus implants to help repair meniscal tears and failed meniscectomies.
Key Finding: Collagen meniscus implantation is a means of biologic reconstruction of complex tears in the meniscus, demonstrating a method of functional joint preservation in patients with complex meniscus tears.
Kevin R. Stone, Wendy S. Adelson, Johnathan R. Pelsis, Ann W. Walgenbach, Thomas J. Turek
Research Question: What is the long-term survival and patient-reported outcomes of concomitant meniscal allograft transplantation performed with articular cartilage repair in knees with moderate to severe cartilage damage?
Prospective report of 119 meniscal allograft transplantations in 115 patients undergoing concomitant articular cartilage repair.
Key Finding: 79.9% of procedures were intact at a mean follow-up time of 5.8 years. Kaplan-Meier estimated mean survival time was 9.9 years in patients undergoing meniscal allograft transplantation with concomitant articular cartilage repair.
Kevin R. Stone, Ann W. Walgenbach, Shadera Slatter, Thomas J. Turek, Caroline Ferguson-Dryden, Marie Dicker, Emma Miltenberger, Haley Cowles, Vivian Liu, Stephanie Wu, Mani Vessal
Research Question: Can meniscus allograft transplantation delay or prevent knee replacement in older patients?
Meniscus allograft transplantation in conjunction with biologic knee restoration procedures can effectively delay or prevent the need for total knee replacement in patients older than 50 years.
Key Finding: Meniscus allograft transplantation with biologic knee restoration improved pain and function in patients over 50 years old. Patients who progressed to knee replacement delayed the need for one by a mean time of 8.64 years.
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