Is There a Difference Between Medial and Lateral Femoral Condyle Allografts? An Outcome and Survivorship Analysis

Background: Focal chondral and osteochondral defects in the knee are often difficult to treat. One solution is the use of osteochondral allograft (OCA) transplantation. The literature deliberates lesions located in the medial femoral condyle (MFC), but little is discussed regarding the lateral femoral condyle (LFC). Purpose: To compare graft survivorship and patient-reported outcomes (PROs) among patients who underwent OCA transplantation of the LFC to the MFC. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 319 patients who underwent primary OCA transplantation of the LFC (n = 111) and MFC (n = 208) were identified. Reoperations were recorded, and OCA failure was defined as allograft removal. PROs included the Knee injury and Osteoarthritis Outcomes Score (KOOS), the International Knee Documentation Committee (IKDC) score, the modified Merle d’Aubigné-Postel score, and satisfaction. Results: Patients with MFC grafts were older than those with LFC grafts (33 and 26 years, respectively; P < .001) and had a slightly higher body mass index (25.6 and 24.4 kg/m 2 , respectively; P = .039). Diagnosis, sex, and allograft size did not differ between groups. Reoperations occurred in 27.9% of MFC grafts and 26.1% of LFC grafts ( P = .737). OCA failure occurred in 12% of MFC grafts and 9% of LFC grafts ( P = .413). The 10-year survivorship was 88% for MFC grafts and 92.9% for LFC grafts ( P = .543). Among in situ allografts, the mean follow-up duration was 9.4 years for MFC grafts and 8.6 years for LFC grafts ( P = .313). At the latest follow-up, the IKDC pain subscale and total scores were similar, but function subscale scores differed significantly between LFC (6.8 ± 2.4) and MFC (7.5 ± 2.1) patients ( P = .019). KOOS and Merle d’Aubigné-Postel scores were similar between patients with MFC and LFC grafts. Patients with MFC grafts reported higher satisfaction than those with LFC grafts (93.7% vs 86.3%, respectively; P = .041). Conclusion: OCA transplantation of the LFC demonstrates high graft survivorship and significant improvement in PROs at mid-term follow-up. Clinical outcomes, reoperation rates, and survivorship were comparable to OCA transplantation of the MFC. These findings suggest that OCA transplantation of the LFC represents a reliable treatment option in appropriately selected patients.