2025 ISAKOS Congress in Munich, Germany

2025 ISAKOS Biennial Congress Paper


Clinical Outcomes, Graft Failure Rate, and Incidence of Structural and Symptomatic Osteoarthritis in an ACL Revision Cohort: Minimum 10-Year Onsite Follow Up in the Mars Cohort

Rick W. Wright, MD, Nashville, TN UNITED STATES
Vanderbilt University Medical Center, Nashville, TN, UNITED STATES

FDA Status Not Applicable

Summary

This is results of onsite follow-up greater than 10 years in the MARS cohort

Abstract

Background

Revision anterior cruciate ligament (ACL) reconstruction has been demonstrated to have inferior outcomes compared with primary ACL reconstructions in terms of patient-reported outcomes, return to activity and sport, and graft rupture rates. However, the long-term assessment of patients undergoing revision ACL reconstruction remains unknown.

Hypothesis

The purpose was to assess long-term outcomes, including graft failure, and signs and symptoms of knee osteoarthritis (OA) at 10 years post-operatively.

Methods

Patients were brought back for onsite physical evaluation, which included bilateral range of motion, KT-1000, radiographs and a physical exam by independent blinded sports medicine physicians. Validated PROMs including IKDC, KOOS, WOMAC, and Marx activity rating scale were also obtained. Symptomatic OA was defined by the KOOS Pain subscale < 70 points. Structural OA was defined as a Kellgren-Lawrence grade of 3 or 4 on radiographs. Multivariate regression models were used to determine the predictors for structural and symptomatic OA at 10 years follow-up, controlling for patient’s age, sex, BMI, baseline PROMs, ACL graft choice, prior and current meniscal pathology and treatment at the time of revision surgery, chondral pathology at the time of revision surgery, and incidence of any subsequent surgeries.

Results

205 patients (107 [52.4%] females) returned at average 12-year follow-up (range, 10-16 years). The mean (SD) age at the time of onsite evaluation was 40.2 (10.4) years with a BMI of 25.7 (range, 17.0 – 42.0).
Physical exam demonstrated loss of extension in 118 (58%) and extension less than full in 84 (41%). A soft Lachman endpoint was noted in 41 (20%), Lachman >5mm in 20 (10%) and 26 patients (13%) had a grade 2 pivot shift and 4 (2%) had a grade 3 pivot shift. KT-1000 measurements demonstrated 23 (11%) patients with 5mm or greater side-to-side difference. The blinded surgeons in their opinion detected 37 (18%) with a nonfunctional ACL.
Radiographs demonstrated that 115 (56%) exhibited joint space narrowing of the tibiofemoral joint (K-L grades 3-4) in their involved knee compared to 28 (14%) in their uninvolved knee. The significant drivers of a higher KL grade (structural OA) at 10 years were found to be higher age, higher baseline BMI, having a medial meniscus excision performed either prior to or at the time of revision surgery, having a prior lateral meniscal excision, or a subsequent surgery (p<0.05). Sex, baseline activity level, graft choice, and chondral pathology at the time of revision were not significant. There were 40 onsite subjects (20%) that reported KOOS pain scores of < 70 points (defined as symptomatic OA), while 91 subjects (44%) reported KOOS pain scores over 90 points (defined as no pain).

Conclusion

Outcomes in this revision ACL cohort at minimum 10 years follow-up demonstrates worrisome outcomes at a still young age. This study demonstrated a loss of ROM in 41-58% of the cohort, an 18% graft failure rate, 56% who exhibited KL grades of 3-4, and 20% who reported KOOS pain scores of less than 70 points, which collectively, all emphasize the challenge of managing the revision ACL reconstruction patient.