A Radiographic Sizing Algorithm for Tibial Plateau Osteochondral Allografts

Objective Tibial plateau osteochondral allograft transplantation is a promising treatment for symptomatic chondral damage of the proximal tibia due to a variety of etiologies. The purpose of this investigation is to develop an accurate and reproducible algorithm for sizing tibial plateau allografts based on recipient radiographs. Design A cadaveric study was performed in which radiographs of 10 fresh frozen cadaveric knees were compared to measured digital photographs of the disarticulated specimens. By comparing the average distance between standard anatomical landmarks on the radiographs to the gross specimens, a correlation factor was calculated that could be applied to recipient radiograph measurements for more accurate sizing of tibial plateau allografts. Results In the coronal plane there were no differences between the mean radiographic and mean morphologic measurements of either the medial or lateral tibial plateau. However, in the sagittal plane the anatomic specimens of the medial and lateral plateau were 90% and 80%, respectively, of the measurements made from the lateral radiograph. Conclusions This cadaveric investigation is the first to propose a sizing algorithm for tibial plateau osteochondral allografts. Based on the results, an anteroposterior radiograph can reliably measure the width of both the medial and lateral tibial plateau without any correction needed. The average morphological lengths of the medial and lateral tibial plateau, on the other hand, were found to be 90% and 80%, respectively, of the radiographically measured lengths. Without correction, this would lead to the implantation of oversized grafts that may contribute to early failure.