The results and morbidity of varus osteotomy for Perthes' disease

The results of varus proximal femoral osteotomy in 55 hips in 52 patients were analyzed by Harrison's radiologic autoassessment method. Excluding operations upon Catterall Grade 1 hips, 75.6% were either therapeutic successes or unchanged; 24.4% were therapeutic failures. These results are compared with and shown to be similar to those of patients treated conservatively by the Birmingham splint. In ten children with Catterall Grade 1 disease, seven were unchanged but three were therapeutic failures. Improved end results occurred in hips with greater surgical varus than those in which the end result worsened, but the statistical significance was questionable. The bone remodelling in response to surgical varus was unpredictable, but the greater the surgical varus the less the correction of the neck shaft angle at follow-up evaluation. Chronologic age cannot be used to predict such bone remodelling as may be impaired by the disease process. An analysis of the incidence and significance of leg shortening, limping, and abductor lurch is presented and some observations made on trochanteric overgrowth and the effect of surgery on the rate of femoral head reconstitution. New attempts to achieve containment of the hip by high-femoral osteotomy may determine the effects of a combination of varus and selective rotation osteotomy using ultrasound scans to measure femoral torsion before operation.