UC San Diego

BACKGROUND: Accurate donor-recipient matching of the femoral condyle radius of curvature (ROC) in osteochondral allograft (OCA) transplantation may aid in minimizing articular surface incongruities. Matching linear femorotibial dimensions, such as the femoral condyle anterior-posterior length (APL), femoral condyle width (lateral-medial length, LML), femoral hemicondyle width (HCW), and tibial plateau width (TPW), can provide similar results if they correlate well with ROC. This study investigates the relationship between femorotibial dimensions and ROC at the cartilage surface using magnetic resonance imaging (MRI). METHODS: Deidentified MRI images of 63 patients (35 men, 33 ± 10 years old, and 28 women, 27 ± 8 years old) were analyzed. Axial images were used for APL, LML, and TPW (TPW-Ax) measurements, while coronal images were used for HCW and TPW (TPW-Cor) measurements. Cartilage was segmented in true sagittal images at the medial femoral condyle (MFC) and lateral femoral condyle (LFC) to calculate their specific cartilage surface ROCs. Linear regression models were used to determine the relationship between the femorotibial dimensions and ROC. RESULTS: Cartilage ROC was significantly correlated with all the linear femorotibial dimensions at the MFC (P < 0.01, R2 = 0.78, 0.69, 0.67, 0.59, and 0.37 for ROC correlations with APL, LML, TPW-Ax, TPW-Cor, and HCW, respectively), and the LFC (P < 0.01, R2 = 0.81, 0.61, 0.56, 0.54, and 0.41 for ROC correlations with APL, LML, TPW-Ax, TPW-Cor, and HCW, respectively). CONCLUSIONS: The APL was the most predictive femorotibial dimension of the cartilage surface ROC. Donor-recipient APL matching in OCA transplantation may provide a similar level of matching to that achievable by direct ROC measurements. The APL matching may help reduce cartilage incongruities, particularly for patients with large osteochondral lesions, in which the ROC measurement cannot be accurately determined.