Outcome of Trochanteric Femoral Fracture Treatment with Gamma Nail Procedure is Independent of Bone Density

Trochanteric femoral fractures are frequently associated with severe osteoporosis in elderly patients. The failure of devices intended to repair trochanteric fractures, such as the gamma locking nail (GLN), might be related to reduced bone desity. Osteoporosis may also influence pain and walking ability because of low stability in the fracture area. In 74 patients (mean age 76 - 16.5 years), the stability and clinical outcome following treatment with GLN were prospectively evaluated and recorded after 9 (n = 43) and 24 months (n = 34). Vertebral bone mineral density (BMD) was measured via quantitative computed tomography (QCT) at time of operation. Mechanical failure of GLN was recorded by radiographs of the hip. Assessment of outcome included the Harris Hip Score. Regression analysis was done to show the influence of age and BMD on clinical outcome. 9 months after treatment, complete fracture healing without dislocation of the lag screw of the GLN was observed even in patients with low BMD (< 55 mg/cm³ trabecular BMD). Clinical outcome assessed by the Harris Hip Score was independent of BMD at both follow-ups. At the first follow-up, outcome depended on the patient's age, with younger patients (< 70 years) showing better results than elderly patients. The stability of fracture also seemed to influence the outcome. Our results indicate that stabilization of unstable osteoporotic fractures with GLN is associated with few complications and can be accomplished with identical clinical and radiologic results seen in patients with high BMD. The critical factor influencing outcome is patient's age, stability of fracture and not BMD.