Proximal femoral focal deficiency: natural history and treatment.

The leg-length discrepancy in patients with proximal femoral focal deficiency is difficult to treat and is often unmanageable except by amputation. To identify candidates for ablative and nonablative surgery and to outline a rational treatment program, 91 patients (120 femurs) were retrospectively analyzed to determine the relationship of absolute femoral length, relative femoral length, and pelvofemoral stability to the functional effects at maturity of various operative and nonoperative management. The direct relationship of function to Aitken classification was documented and correlated with percent femoral inhibition (p less than 0.01), and pelvofemoral stability as determined by the acetabular index (p less than 0.05), shelf index (p less than 0.001), and acetabular dysplasia (p less than 0.001). In unilateral cases, two therapeutic subgroups were identified: Class I (patients with less than 17 cm of projected extremity shortening, and evidence of pelvofemoral stability), and Class II (patients with greater than 17 cm of predicted extremity shortening). Class I patients are potential candidates for height equalization by ipsilateral lengthening and/or contralateral shortening. Class II patients should have early ablative procedures and conversion to an above-knee or below-knee amputee. In bilateral PFFD, function at maturity was primarily dependent upon leg-length differential, foot position, and associated anomalies.