Comparison of clinical outcomes following osteochondral allograft transplantation for osteochondral versus chondral defects in the knee

Purpose Osteochondral allograft (OCA) transplantation is a restorative technique for addressing articular cartilage defects by transferring mature viable chondrocytes with subchondral bone into size-matched lesions. The purpose of this study was to compare differences in clinical and functional outcomes in patients treated with OCA for osteochondral defects compared with isolated chondral pathology. Methods A retrospective review identified patients who underwent OCA transplantation and grouped them into osteochondral or isolated chondral pathology. Demographic data, surgical history, lesion characteristics, complications, and rate of subsequent surgery were reviewed. The review included 86 patients (24 osteochondral, 62 chondral) with a mean follow-up of 5.4 ± 1.4 years. Outcome measures included the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR.), International Knee Documentation Committee (IKDC), and Short Form Health Survey (SF-12) physical scores. Failure was defined to include revision OCA, graft removal, conversion to ACI, or conversion to arthroplasty. Results The average age at surgery was 32.3 and 37.3 years for the osteochondral and chondral groups, respectively ( P = 0.056). The medial femoral condyle was the most common defect location in both groups. P < 0.05 was considered statistically significant. Patients with osteochondral pathology had significantly greater KOOS JR., IKDC, and SF-12 scores ( P < 0.05), and fewer failures were reported in the osteochondral group (8.3% versus 32.3%, P = 0.045). When controlling for age, sex, laterality, BMI, and presence of a concomitant procedure, patients with osteochondral pathology were found to have better KOOS and IKDC scores, but there was no difference in SF12 scores or rates of failure between groups. Conclusion The findings of this study indicate that patients undergoing OCA for osteochondral defects may have greater functional outcomes and similar failure rates compared with OCA transplantation for isolated chondral pathology.