summary Proximal Femoral Focal Deficiency is a congenital condition caused by a defect in the primary ossification center of the proximal femur that may present with an absent hip, femoral neck pseudoarthrosis, absent femur, or a shortened femur. Diagnosis is made with radiographs of the hip and femur. Treatment is nonoperative or operative depending on location and size of the femoral defect, as well as presence of bilateral involvement. Epidemiology Anatomic location bilateral (15%) Etiology Pathophysiology defect in the primary ossification center (cartilage anlage) Spectrum spectrum of disease includes absent hip femoral neck pseudoarthrosis absent femur shortened femur Genetics primarily sporadic etiology, but rare autosomal dominant form exists associated with sonic hedge-hog gene (limb bud) Associated conditions orthopaedic manifestations fibular hemimelia (50%) ACL deficiency coxa vara knee contractures nonorthopaedic manifestations dysmorphic facies found in rare autosomal dominant type Classification Aitken classification Class Femoral head Acetabulum A Present Normal B Present Mildly dysplastic C Absent Severely dysplastic D Absent Absent Presentation Physical exam severe shortening of one or both legs percentage of shortening remains constant with growth short bulky thigh that is flexed, abducted, and externally rotated normal feet (most common) Treatment Goals of treatment treatment must be individualized based on ultimate leg length discrepancy presence of foot deformities adequacy of musculature proximal joint stability Nonoperative observation indications often in children with bilateral deficiency extension prosthesis indications less attractive option due to large proximal segment of prosthesis assists patient when attempting to pull self up to stand Operative ambulation without prosthesis limb lengthening with or without contralateral epiphysiodesis indications predicated limb length discrepancy of <20 cm at maturity stable hip and functional foot femoral length >50% of opposite side femoral head present (Aitken classifications A & B) contraindications unaddressed coxa vara, proximal femoral neck pseudoarthrosis, or acetabular dysplasia ambulation with a prosthesis knee arthrodesis with foot ablation indications: ipsilateral foot is proximal to the level of contralateral knee prosthetic knee will not be below the level of the contralateral knee at maturity need for improved prosthetic fit, function, and appearance femoral-pelvic fusion (Brown's procedure) indications femoral head absent (Aiken classifications C & D) Van Ness rotationplasty indications ipsilateral foot at level of contralateral knee ankle with >60% of motion absent femoral head (Aiken classifications C & D) surgical technique 180 degree rotational turn through the femur ankle dorsiflexion becomes knee flexion allows the use of a below-knee prosthesis to improve gait and efficiency amputation indications femoral length <50% of opposite side surgical technique preserve as much length as possible amputate through the joint, if possible, in order to avoid overgrowth which can lead to difficult prosthesis fittingfit for prosthesis for lower extremity after 1 year