Treatment of subtrochanteric femur fractures using a submuscular fixed low-angle plate

The purpose of this study was to evaluate the results of using fixed low-angle plates, inserted submuscularly, for the treatment of subtrochanteric femur fractures with regard to femoral neck-shaft angle and union. Twenty patients were identified through our orthopedic trauma registry who had subtrochanteric femur fractures in which the lesser trochanter was detached or without an intact piriformis fossa and who had undergone a repair of their fracture with a submuscular fixed low-angle plate device. We studied a radiographic measurement of the neck-shaft angle, incidence of varus malunion (5 degrees or more), operative time and blood loss, time to radiographic union, and time to clinical union. Our results demonstrated that the time to radiographic union averaged 91 days and time to clinical union averaged 107 days. The average operative time was 108 minutes (range, 43-170 minutes), and estimated blood loss was 418 mL (range, 150-800 mL). The average femoral neck-shaft angle on the plated femur was 133 degrees (range, 125 degrees-145 degrees), as compared with an average of 134 degrees (range, 124 degrees-145 degrees) on the uninjured femur. There were no plate or screw failures or nonunions. Submuscular application of fixed low-angle plate devices resulted in anatomic alignment of the femoral neck-shaft angle while maintaining low rates of implant failure and high rates of union.