Poster 234: Minimum 10-Year Clinical Outcomes and Survivorship of Meniscal Allograft Transplantation with Bone Fixation

OBJECTIVES: Meniscal allograft transplantation (MAT) can reliably reduce pain and improve function in symptomatic patients with meniscal insufficiency without diffuse chondral wear. Ten-year survival rates following MAT have been estimated to be as high as 74%, though previous studies have been limited to small sample sizes or pooled outcomes including patients who have less than 10-year minimum follow- up. The purpose of this study was to report on clinical outcomes and survivorship following primary meniscal allograft transplantation in a large cohort of patients with 10-year minimum follow-up. METHODS: A retrospective review of prospectively collected data was performed to identify patients undergoing primary MAT from 1999-2012. Lysholm, International Knee Documentation Committee (IKDC), and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales were collected preoperatively and at 1-, 2-, 5-, and minimum 10-year follow-up. Cox proportional hazards modelling was utilized to identify variables associated with reoperation and failure. Failure was defined as revision MAT or conversion to unicompartmental or total knee arthroplasty (UKA and TKA, respectively). Reoperation was defined as a subsequent surgical intervention of the transplanted meniscus, including partial or total meniscectomy, meniscal repair, or failure as defined above. RESULTS: A total of 143 patients undergoing primary MAT met inclusion criteria and were followed for a mean of 12.8 ± 2.7 years (range: 10.0 - 21.0). Concomitant procedures were performed in 96 (67%) patients, the most common being osteochondral allograft transplantation (n=50, 35%) (Table 1). Patients demonstrated statistically significant (p ≤ .037) postoperative improvements in all patient- reported outcome measures at all time points, compared to baseline (Figure 1). Fifty-four patients (38%) underwent a meniscal reoperation at a mean time of 6.5 ± 5.4 years (range: 0.3 – 16.7) postoperatively, with the most common reoperation procedure being partial meniscectomy (n=27, 19%). Thirty-five (24%) patients met criteria for failure at a mean time of 7.2 ± 4.9 years following MAT (range: 1.0 - 16.5). Twelve (8%) patients underwent revision MAT, and 23 (16%) underwent conversion to arthroplasty. MAT survival free of meniscal reoperation and failure was 73% and 83% at 10 years and 58% and 69% at 15-years, respectively (Figure 2). At the time of final follow-up, 88% of patients reported being satisfied with their overall postoperative condition. CONCLUSIONS: Primary MAT demonstrates efficacy and durability with high rates of patient satisfaction at minimum 10-year follow-up. Patients should be counseled that while reoperation rates may approach 42% at 15 years, overall revision rates (8%) and conversion to arthroplasty (16%) remain low at long- term follow-up.