Paper 54: Short term outcomes predict long term success following osteochondral allograft transplantation in the knee

Objectives: Osteochondral allograft (OCA) transplantation has demonstrated reliable long-term outcomes in the treatment of chondral and osteochondral lesions of the knee. While several preoperative and intraoperative factors for graft failure have been identified, few studies have described the temporal distribution of failures to forecast long-term graft survival. The aim of this study was to define the timing of OCA failures and use this data to forecast 10-year graft survival. This information will guide patient counseling following osteochondral allograft transplantation in the knee.
Methods: We identified 288 knees (267 patients) that underwent OCA transplantation between 1997 and 2023 for chondral lesions by a single surgeon with a minimum follow-up of 10 years. Graft failure was defined as any reoperation that involved removal of the allograft or conversion to arthroplasty within 10 years. Non-failure reoperations were identified as well. Kaplan-Meier analysis was used to estimate overall and conditional 10-year survivorship, given graft survival through postoperative years 1 to 5.
Results: The median patient age in our cohort was 33.1 years and 58% of patients were male. Concomitant procedures were performed in 107 knees and the median surface area treated at the time of OCA transplantation was 8.4 cm2. Femoral condyle and multifocal grafts comprised 81% of the cohort. Overall graft survivorship was 77% at 10 years postoperatively (Table 1). Graft failure occurred in 62 knees (21.5%) at a median of 2.7 years postoperatively, with roughly half of the failures occurring within the first three years (Figure 1). If the graft was noted to be intact after two years postoperatively, the predicted survival to 10 years postoperatively was 83%. Similarly, predicted 10-year survivorship was 79%, 83%, 88%, 90%, and 92%, given conditional survival through 1, 2, 3, 4, and 5 years postoperatively, respectively. Non-failure reoperations occurred in 65 knees (22.5% of the cohort), with a median time to reoperation of 1.9 years (Figure 2). 46% of non-failure reoperations occurred within the first two years postoperatively, with 73% comprised of arthroscopic debridement or meniscus treatment.
Conclusions: Among patients with minimum 10 years of follow-up, overall graft survivorship following OCA transplantation was 77%. Roughly half of the failures occurred within the first three years postoperatively. The longer the graft was intact without requiring removal, the greater the likelihood to achieve minimum 10-year survival. If the graft was performing well at 4 years postoperatively, there was 90% likelihood that it would survive at least 10 years postoperatively. Similarly, 46% of non-failure reoperations occurred within the first two years. These findings suggest that as patients reach short-term postoperative timepoints, they may be counseled on their progressively increasing likelihood of long-term success.