A Case of Fibrous Dysplasia with Bilateral Shepherd Crook Deformity Treated with Dynamic Hip Screw Fixation.

Introduction: Fibrous dysplasia is a rare benign disorder of the skeletal system characterized by fibro-osseous proliferation with intervening areas of normal or immature bone in the intramedullary region. It can either be a monostotic (involves one bone) or a polyostotic (involves more than one bone) presentation and usually occurs equally in males and females. Deformities such as scoliosis and shepherd's crook deformity are frequently encountered in the polyostotic form. We report the management of a rare managed case of bilateral shepherd's crook deformity of the proximal femur with impending neck of femur fracture.

Case Report: A 22-year-old male known case of polyostotic fibrous dysplasia presented with bilateral shepherd's crook deformity of the proximal femur. Preoperatively, neck-shaft angle was 15° on the right side and 55° on the left side. The patient had severe pain on the right side due to an impending neck of femur fracture. On the right side, we first did a valgus osteotomy in the subtrochanteric region and fixed with dynamic hip screw, and after 3 months, the left proximal femur valgus osteotomy with dynamic hip screw fixation was done. Postoperatively, we achieved a neck-shaft angle of 140° on the right side and 135° on the left side. 1-year follow-up imaging showed union at both the osteotomy sites. At present, at 12-month post-operative, the patient is walking full weight-bearing without support, no apparent shortening.

Conclusion: Valgus osteotomy is an easy and effective method to correct the shepherd's crook deformity and achieve correct mechanical alignment. Valgization of the shepherd crook deformity will prevent the development of a pathological neck of femur fracture.