Surgical Technique and Clinical Outcomes of Osteochondral Autograft Transplantation for Large Osteonecrotic Lesions of the Femoral Condyle With Residual Normal Cartilage: The Eyeglass Technique

Abstract

Background: Osteochondral autograft transplantation (OAT) is usually performed for a defect that is <400 mm2 because of the limitations of autografts. Purpose: To present the surgical technique and clinical outcomes of OAT using the eyeglass technique for large osteonecrotic lesions of the femoral condyle (LOFs) (>400 mm2) with residual normal cartilage. Study Design: Cohort study; Level of evidence, 3. Methods: Cases (group 1) included 15 patients (18 knees) who underwent OAT using the eyeglass technique for LOFs with residual normal cartilage, while controls (group 2) included 11 patients (11 knees) who underwent OAT using the standard technique for small osteonecrotic lesions of the femoral condyle (≤400 mm2). Clinical outcomes were evaluated preoperatively and at the final follow-up (group 1, 56 months; group 2, 48 months) according to the International Knee Documentation Committee (IKDC) objective grade, the IKDC subjective score, and the Japanese Orthopaedic Association (JOA) score. Results: The mean lesion size was 685 mm2 in group 1 and 230 mm2 in group 2. Patients in group 1 had postoperative scores equivalent to those in group 2. The postoperative IKDC subjective scores in group 1 (mean, 86.9) and group 2 (mean, 87.0) showed no significant difference at the final follow-up ( P = .653). For postoperative IKDC objective grades, 83.3% of group 1 and 81.8% of group 2 were graded as “nearly normal” or better, and no significant intergroup difference was found for the IKDC objective grade ( P = .989). Also, no significant intergroup difference was found for the postoperative JOA score (group 1, 93.9; group 2, 81.4; P = .480). Nine second-look arthroscopic procedures were performed in group 1 compared with 4 in group 2, and all patients had plugs that were graded as “nearly normal” or better by the International Cartilage Repair Society classification system. Conclusion: The postoperative results of patients who underwent OAT using the eyeglass technique for large osteonecrotic lesions (>400 mm2) were equivalent to the results of patients who underwent OAT using the standard technique for small osteonecrotic lesions (≤400 mm2).