A two- stage surgery for severe femoral neck deformity due to fibrous dysplasia: a case report.

Various kinds of surgical treatments have been reported for varus deformity of the proximal femur due to fibrous dysplasia. We report a case of two-stage corrective osteotomy for severe varus-retroversion deformity of the femoral neck due to monostotic fibrous dysplasia. The patient was an 18 year-old man. On initial examination, the spina malleollar distance was 88 cm on the right side and 83 cm on the left. Plain radiography showed prominent varus deformity of his left proximal femur. The morphology was 130 degrees on the right side and 85 degrees on the left. Computed tomography revealed 60 degree retroversion of the femoral neck. A two-stage surgery was performed, consisting of curettage and bone grafting followed by corrective osteotomy 16 months later. A 55 degree valgus osteotomy was performed in the subtrochanteric region. After osteotomy and 40 degree internal rotation of the shaft, a 130 degree angle plate was used for osteosynthesis. Postoperative radiological examination showed a morphology of 140 degrees and computed tomography revealed a 20 degree retroversion of the femoral neck. No recurrence or varus deformity was seen at four years after surgery. Although the leg length discrepancy was 2.5 cm, the patient had no difficulty in one foot standing and no restriction of ADL (activity of daily living). The well-known progressive varus Shepherd's crook deformity in the polyostotic form of fibrous dysphasia is associated with limb shortening, limping, and occasionally chronic fatigue fractures with disabling pain. Various kinds of surgical treatments have been reported for this type of varus deformity. Curettage and bone grafting is one of the most common and simple treatments. However, this method often gives bad results as the grafted bones are absorbed and that the progress of varus deformity van not to be prevented. We report a case of two-stage corrective osteomy forsevere varus-retroversion deformity of the femoral neck due to monostotic fibrous dysplasia.