The Posterior Femoral Condyles: A Potential Donor Site for Mosaic-Like Osteochondral Autograft?

Abstract

The purpose of this study was to assess whether it was possible to harvest plugs from the posterior femoral condyles with a standard mosaicplasty instrumentation through retroligamentous approaches and whether the plugs harvested from the posterior condyles presented the same characteristics as those harvested from the standard donor sites regarding the length, cartilage thickness, and cartilage angle. An anatomic study has been conducted on 15 cadaveric knees. Osteochondral plugs were harvested with a 10-mm tubular chisel from the standard donor sites and from the posterior condyles. The plugs were analyzed regarding the length, cartilage thickness, and angle between the axis of the plug and the cartilage surface (cartilage angle). Two plugs harvested from the posterior condyles were not suitable for implantation. Between the different donor sites, the cartilage thickness of the lateral side of the intercondylar notch was significantly thinner (mean, 1.57 mm; SD, 0.46) than the other standard donor sites (P < .05). The mean cartilage thickness was 2.35 mm (SD, 0.72) for the posteromedial condyle and 1.96 mm (SD, 0.67) for the posterolateral condyle. The mean angle was 19.7° (SD, 15.5) for the posteromedial condyle and 13.8° (SD, 8.6) for the posterolateral condyle. Whereas the cartilage thickness of the posterior condyles is comparable to other donor sites, the technical difficulty in obtaining plugs perpendicular to the articular surface precludes the use of the posterior condyles in anything but the rarest circumstances. Routine use of these 2 donor sites cannot be recommended. The posterior condyles cannot be proposed as a donor site for osteochondral autograft with a mosaicplasty instrumentation because it is difficult to obtain plugs with a perpendicular cartilage surface from this localization.