Magnetic Resonance Imaging for Examination of Proximal Femoral Fractures: Its Constribution to Clinical Medicine

Abstract

Purpose of the Study: The aim of the study was to find out, by magnetic resonance (MR) imaging, the degree of blood supply impairment in the femoral head in proximal femur fractures. Material: Twenty-eight patients, 22 women and six men, aged between 49 and 96 years (average, 75.2 years) were evaluated. Twenty-six patients were examined within 2-48 hours of injury, one patient at 72 hours (3 days) and one at 144 hours (6 days). Two groups were made: A, including 18 patients with an intra-articular fracture of the femoral neck, and B, consisting of 10 patients with an extra-articular fracture (per- to subtrochanteric fractures) for comparison. Methods: Native and contrast-enhanced (intravenous injection of Magnevist) MR images were obtained. An MR pulse sequence permitting fat signal suppression (T1, TSE, FS) was used in coronal and transversal planes. Results: In all B group patients, enhancement in the femoral head following contrast medium application was seen as even; enhancement was also shown in two group A patients with locked fractures. These results indicated that blood supply to the femoral head remained intact. Five group A patients showed enhancement in some areas of the femoral head only, and this finding corresponded to partial damage to the femoral vasculature. In the remaining 11 patients of group A, no post-contrast enhancement could be distinguished. This finding suggested extensive damage to the femoral vasculature associated with a high risk of post-traumatic avascular necrosis (AVN). In the contralateral femurs of the patients from both groups, contrast enhancement in the femoral head was fully visualized, with the exception of one patient whose contralateral femoral head showed signal alteration typical of advanced AVN (non-traumatic in origin). Discussion: The authors recommend the use of this method in patients with intra-articular fractures of the femoral neck that are between 40 and 65 years of age. For this patient category, MR results have a crucial role in the choice of an appropriate therapy including the surgical procedure to be used (osteosynthesis vs total hip arthroplasty/ THA/). To perform osteosynthesis of the femoral neck is less demanding in terms of surgical skills and treatment costs than THA. Since the former method preserves the femoral head, it is preferred if blood supply is not disturbed. THA is the method of choice in hips with impaired blood supply to the femoral head and with a high risk of post-traumatic AVN.