Leg length discrepancy in Legg-Calve-Perthes disease.

The purpose of this study was to determine the incidence of the leg length discrepancy (LLD) in Legg-Calve-Perthes disease and whether there is any correlation between LLD and age at onset, gender, type of treatment, and severity of disease. The study population consisted of 261 patients with unilateral involvement who had reached skeletal maturity at last follow-up. All hips were treated by containment methods (bed rest and traction in abduction, Petri cast, brace, varus osteotomy, Salter osteotomy, and shelf acetabuloplasty). The late results were classified according to the Stulberg classification. LLD was found in 33 patients and ranged from 1 to 5.2 cm (average 2.51 cm). The limb shortening was observed in Herring group B (average 2.18 cm) and C (average 2.82 cm) and was statistically significant more common in group C. The statistical analysis revealed no statistical difference between the age at onset, sex, and type of treatment with regard to LLD; nevertheless, patients in Herring group C with LLD were younger than patients in group B, and LLD was seen more often after varus osteotomy. The amount of residual shortening of the affected limb in Legg-Calve-Perthes disease at the end of skeletal growth seems to depend on the extent of involvement and the presence of a growth arrest. A varus osteotomy produces more significant shortening than other methods of treatments. The age at the onset of symptoms and sex do not influence the amount of LLD, but early onset of the disease can result in more severe limb shortening.