Ideal Donor Site for Osteochondral Autografting of the Distal Femur Using Radius of Curvature: A 3-Dimensional High-Resolution Scanner Comparison

Abstract

Objective To compare radius of curvature (RoC) of distal femur osteochondral autograft transfer (OAT) donor sites from the intercondylar notch and trochlear ridge with recipient sites on the distal and posterior condyles and evaluate differences between recipient sites. Design Nineteen cadaveric femurs were scanned with a 3-dimensional high-resolution sensor. Donor regions included the lateral (LTR) and medial trochlear ridges (MTR), and the lateral (LICN) and medial intercondylar notch (MICN). Recipient regions analyzed were the distal medial (DMFC), posterior medial (PMFC), distal lateral (DLFC), and posterior lateral femur condyle (PLFC). Six-millimeter OAT grafts were simulated, and average RoC of all regions was compared using an analysis of variance. Post hoc testing was performed using Fisher’s least significant difference. Results We found no significant differences in RoC of the LICN compared with all 4 recipient sites ( P = 0.19, 0.97, 0.11, and 0.75 for DLFC, PLFC, DMFC, and PMFC, respectively) or the LTR and MTR to the posterior condyles (LTR vs. PLFC and PMFC; P = 0.72, 0.47, MTR vs. PLFC and PMFC P = 0.39, 0.22, respectively). Significant differences were found for RoC of the MICN compared with each recipient site ( P < 0.001) and between distal and posterior femoral condyles (DLFC vs. PLFC, P = 0.016; DMFC vs. PMFC, P = 0.023). Conclusion The LICN is the ideal donor option for all recipient sites on the femoral condyles with respect to RoC of 6-mm OAT plugs. The MTR and LTR were acceptable donor sources for the posterior condyles, while the MICN was a poor match for all recipient sites. Additionally, the distal femur condyle and posterior femur condyle have different RoCs.

Compressibility of Osteochondral Autograft Transfer Donor Grafts: A Comparison of Different Donor Regions and How Much Shortening Occurs of Plugs After Impaction

“… 19 Ideally, an OAT graft would sit flush in the recipient site with respect to cartilage contour and thickness. 21 Various techniques recommend harvesting a plug 1 to 2 mm longer than the recipient hole to allow for graft impaction. 4 , 10 , 29 A clinical dilemma exists with regard to leaving an osteochondral plug slightly proud versus subjecting the graft to additional force to seat the graft flush with the surrounding articular cartilage.…”