Anthropometric Measurements of Distal Femur to Design the Femoral Component of Total Knee Arthroplasty for the Iranian Population

Background: Acquiring knowledge about anatomic and geometric quantities of bones is among the most vital parameters in orthopedic surgery that has a significant effect on the treatment of various disorders and subsequent outcomes. The aim of this study was to obtain anthropometric information for distal femur in order to compare with similar dimensions of prosthesis used in total knee arthroplasty (TKA) surgery and to design more suitable and optimal components. Methods: Morphological data of distal femur were measured in 132 knees (81 males and 51 females) using magnetic resonance imaging (MRI). The data included anterior-posterior (AP) length, medial-lateral (ML) width, medial AP (MAP), lateral AP (LAP), MAP to LAP distance in the anterior distal femur namely anterior medial lateral (AML) width, medial and lateral condyle width, and intercondylar notch. The aspect ratio (ML/AP) was also calculated and the results were compared with similar dimensions of currently used knee implants. Results: Our data showed that men are significantly larger in all dimensions than women. In the distal femur with similar AP lengths in both sexes, women had a smaller ML width than men (P<0.001). Comparison between the distal femur and studied prostheses showed no high correlation and similarity between the femoral component and femoral condyle prostheses in the resected surface of the bone. Conclusion: The results of this study can provide the data needed to design prostheses suitable for the Iranian population.