Knee Subluxation During Femoral Lengthening in a Six Year Old Boy with Congenital Coxa Vara and Congenital Short Femur

A 6 year old boy with congenital short femur and coxa vara underwent staged correction of his deformities. First he had hip reconstruction with a proximal femoral valgus osteotomy and Dega pelvic osteotomy that was followed 6 months later by femoral lengthening. During the course of his lengthening, he developed a flexion contracture of his knee of 45° and subluxation of his knee. The distraction was stopped after obtaining 3.5 cm lengthening. He was admitted to the hospital, and after 2 weeks in traction and intense physiotherapy that failed to reduce the subluxation, he was taken to the operating room and had release of his Tensor Fascia Lata (TFL),” following which the subluxation was reduced. He was then put in a special type of Knee Ankle Foot Orthosis (KAFO) with hinges at the knee and a turnbuckle to maintain the knee in full extension.