Closing lateral wedge valgus osteotomy with dynamic hip screw for the treatment of varus nonunion of pertrochanteric fracture: can restoration of biomechanics and stabilization alone heal?

INTRODUCTION

Nonunion of pertrochanteric fracture is rare and its occurrence especially without prior surgical intervention has been hardly ever reported. Hence there is not much literature describing the best way to treat them. Nonunion of pertrochanteric fracture collapses in to varus by virtue of deforming action of muscles and thus deranging the biomechanics of the hip and indirectly preventing fracture union further. Hence it is very important to re-orient the abductor lever arm to biomechanically advantageous normal configuration favoring fracture healing. In general, principles of treatment of nonunion like open reduction of the fracture with freshening of fracture fragments, stabilization and bone grafting are very difficult to the surgeon and the patient.

METHOD: We herewith describe for the first time in literature a prospective nonrandomized study of closing lateral wedge valgus intertrochanteric osteotomy in addition to dynamic hip screw osteosynthesis in the successful management of seven patients with varus trochanteric nonunion. Average operating time was 63 +/- 13 min (range 39-93 min) and blood loss was 212 +/- 32 ml (range 156-320 ml). Average pre-operative coxa vara of 94 degrees +/- 7 degrees (range 85 degrees -104 degrees ) had improved to a femoral neck shaft angle of 139 degrees +/- 4 degrees (range 134 degrees -145 degrees ) on postoperative radiographs.

RESULTS

All fractures and osteotomies had healed uneventfully at the last follow-up with good functional outcome. Harris Hip score had improved from 34 +/- 6 (range 22-47) to 89 +/- 4 (range 83-95) at an average of 11 months (range 7-13 months) follow-up. Valgus osteotomy converts shear forces across the fracture site into compressive forces thus achieving union.