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ABSTRACT: Developmental coxa vara is an infrequent deformity found in children. A review of records at a busy teaching institution over a 36 year period revealed the diagnosis of only 18 cases. Thirteen hips underwent surgical correction. In this series a subtrochanteric femoral osteotomy was the treatment of choice. Followup of the surgically treated patients through skeletal maturity ranged from four to 15 years; a gain in leg length, and increase in hip motion, with elimination of a positive Trendelenburg gait, frequently was noted. This limp, though reduced, persisted in all instances. Premature closure of the proximal capital femoral epiphysis was noted postoperatively in five cases. While the specific cause of this early epiphyseal closure remains unknown, several possibilities are discussed.
Introduction
Coxa vara is a relatively uncommon hip problem, and is defined as any decrease in the angle formed by the femoral neck with the femoral shaft from the normal of 120° to 135°. '"4 It was described by Fiorani in 1881, several years before the discovery of roentgenograms.5 The name coxa vara was coined by Hofmeister in 1894, and congenital coxa vara was described by Kredel in 1896.2'5* Nilsonne in 1924 suggested that failure of ossification of the cartilaginous neck of the femur may be due to an embryonic vascular disorder.5 Barr in 1929 classified coxa vara.7 This classification was enlarged upon by Amstutz and Wilson in 1962.8 Amstutz in 1970 delineated the differences seen in congenital, developmental and acquired coxa vara.9 Roentgenographic examination offers the most readily available means of diagnosing developmental coxa vara. Frequently the overall picture suggests a fracture of the femoral neck with resultant nonunion. There is a depression of the neck of the femur, and the epiphyseal plate is vertical instead of horizontal, usually with a branching at the inferior portion much like an inverted Y enclosing bone between its arms (Fig. 1).
Treatment of developmental coxa vara can only be accomplished surgically. Corrective valgus subtrochanteric or intertrochanteric femoral osteotomy is the treatment of choice and has almost universally proved successful by converting a vertical defect across which sheering forces play into a horizontal defect with compression forces exerted.4"7'9"13 If untreated, the condition proceeds to an established nonunion, usually with resultant incongruity of the hip joint,...