THE GUARDED PROGNOSIS FOR GREATER TROCHANTERIC FRACTURES IN ADOLESCENCE

Abstract

Introduction: Acute traumatic separation of the greater trochanter is a rare childhood injury with associated morbidity. Although the risk for femoral head avascular necrosis and morbidity following femoral neck fractures in childhood is well understood, the risk to femoral head blood supply in the much less common greater trochan-teric fracture is not widely known.

Materials and Methods: Three adolescents with greater trochanteric fracture were evaluated and treated. The first, a complete separation incurred in football, was fixed by open surgery using two large A-O screws plus washers. The patient developed severe avascular necrosis requiring further treatment including bone grafting of the femoral head plus shelf acetabuloplasty. The prognosis is guarded. A second patient had a similar injury following a fall from a ladder. Because of our experience with the prior case, she was treated with a careful, minimal open reduction with greater trochanter reat-tachment using a tension band technique. Follow-up has shown a normal femoral head. A third patient presented with progressive pain in the greater trochanter in sporting activities with early separation documented by radiograph. This picture was similar to slipped capital femoral epiphysis. Treatment was by emergent in-situ screw fixation. The hip has developed normally.

Discussion: The growth centers of the femoral head and greater trochanter are conjoined at birth with a similar blood supply The blood supply to the femoral head and neck as well as to the greater trochanter have been carefully studied but with little attention paid to the effect that greater trochanteric fracture might have on femoral head blood supply. The ascending branches of the medial femoral circumflex, which supply the blood to the femoral head via their course to the posterior femoral neck, can readily be injured with traumatic avulsion of the greater trochanter. Femoral head avascular necrosis can result from the fracture itself and/or to the methods of re-attachment.

Recognizing the risk , patients with this injury should be treated with a gentle open reduction with a minimal added trauma from reduction methods or fixation. K-wires and a tension band technique may be the best choice. The child should then be immobilized in a hip spica cast to allow full healing, rather than relying on large internal fixation devices in an attempt to avoid cast immobilization. Adolescents with this injury must be followed for two years to be certain that avascular necrosis does not develop.