Radiological assessment of the femoral bowing in Japanese population.

Ahmed Hamed Kassem Abdelaal,Akihiko Takeuchi,Donnel A Rubio,Katsuhiro Hayashi,Hiroyuki Tsuchiya,Shinji Miwa,Ahmad Fawaz Morsy,Yoshitomo Kajino,Norio Yamamoto

doi:10.1051/sicotj/2015037

Abstract

Introduction: Differences in the magnitude of bowing between races are well-known characteristics of the femur. Asian races have an increased magnitude of femoral bowing but most of the orthopedic implants designed for the femur do not match this exaggerated bowing. We calculated the sagittal and coronal femoral bowing in the Japanese population at different levels of the femur and addressed its surgical significance. Material and methods: We calculated the sagittal and coronal bowing of 132 Japanese femora using CT scan of the femur. A mathematical calculation of the radius of curvature at proximal, middle, and distal regions of the femur was used to determine the degree of femoral bowing. Results: Mean sagittal bowing of the femur was 581, 188, and 161 mm for the proximal, middle, and distal thirds of the femur and mean lateral bowing was 528, 5092, and 876 mm, respectively. Mean sagittal and coronal bowing for the whole femur was 175 and 2640 mm, respectively. No correlation was found between age, gender, length of femur, and the degree of bowing. Conclusion: Our study reveals that femoral bowing in the Japanese population is 175 mm in the sagittal plane and 2640 mm in the coronal plane; these values are greater than the femoral bowing in other ethnic groups studied in the literature.This may result in varying degrees of mismatch between the western-manufactured femoral intramedullary implants and the Japanese femur. We recommend that orthopedic surgeons to accurately perform preoperative evaluation of the femoral bowing to avoid potential malalignment, rotation, and abnormal stresses between the femur and implant.

Highlights

Racial and ethnic group differences in femoral curvature have been studied by anthropologists and forensic scientists [1, 2]
Tumor surgeons must have adequate knowledge and experience in addressing the potentially abnormal bony anatomy which may be encountered in a major reconstructive procedure of the femur
When reconstruction of the limb by stemmed tumor prosthesis is planned, consideration must be given to the variable planes and magnitude of femoral bowing and the possible mismatch which may be encountered when implanting a standard curved stem with unidirectional sagittal plane bowing and no curve in the coronal plane

Summary

Introduction

Racial and ethnic group differences in femoral curvature have been studied by anthropologists and forensic scientists [1, 2]. Ballard and Trudell measured anterior femoral curvature by placing femurs on a flat surface and measuring the height of the bow [2]. They found that blacks had a greater radius of curvature than whites. The idea that these racial differences may require modification of orthopedic trauma implants is not a new concept [3]. Tumor surgeons must have adequate knowledge and experience in addressing the potentially abnormal bony anatomy which may be encountered in a major reconstructive procedure of the femur

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Results

Discussion

Conclusion