Distance Between Femoral Bump and Retinacular Vessels in Cam-Type Femoroacetabular Impingement (SS-43)

Abstract

Introduction The complete resection of the femoral bump is essential in the treatment of cam-type femoroacetabular impingement (FAI). The lesion of the retinacular vessels is possible during the resection of the most lateral portion of the femoral bump. The purpose of this study is the measurement of the distance between the femoral bump resection and the entry point of the retinacular vessels into the femoral head. Methods During a one-year period (October 2007-2008) we performed a CTscan with 3-D reconstruction in 60 patients with Cam-type FAI (34 males, 26 females, mean age 36, 5 years) before and after arthroscopic resection of the femoral bump. We identified the foraminas, corresponding to the entry point of the retinacular vessels into the femoral head. During the arthroscopy the retinacular vessels were identified prior to the bump resection. One year after hip-arthroscopy a clinical evaluation was realized to exclude avascular necrosis (AVN) of the femoral head. Results The mean distance between the most anterior foramina to the lateral limit of the femoral bump was 6.1 mm (1.1mm-17 mm). In the clinical evaluation 1 year after arthroscopy no patient presented with clinical signs suggesting AVN of the femoral head. Conclusion A CTscan with 3-D reconstruction helps to identify the lateral limit of the femoral bump and the entry point of the retinacular vessels into the femoral head. Because the lateral limit of the femoral bump extends close to the retinacular vessels, we recommend arthroscopic visualization of these vessels prior to the resection of the lateral portion of the femoral bump.