Simultaneous Knee and Hip Dislocation During Femoral Lengthening in a Patient with Congenital Short Femur

Congenital short femur (CSF) is a type of bone dysplasia with an incidence of about 1 in 50,000 births. It can range from simple hypoplasia to proximal femur deficiency. Recently hip stability and anatomic variance have also been described in diagnosing and classifying this disease. It is the malformation most commonly associated with fibular hemimelia, present in 50% of such patients. CSF can have multiple associated deformities including acetabular dysplasia, coxa vara, femoral head retroversion, dysplasia of the lateral condyle of the femur, hypoplasia of tibial eminence, flattening of tibial plateau, anteroposterior knee instability, and ball and socket deformation of the ankle joint. We present the case of a patient with CSF who underwent femoral lengthening but during the course of treatment, suffered ipsilateral posterior hip and knee dislocation. Treatment was complicated by concomitant psoriasis, a disease which is known to exacerbate when a patient is under stress.