Abstract
In a radiological study, we evaluated the outcome of the Chiari osteotomy as a primary method of femoral head containment in a distinct group of patients with Perthes’ disease. Even when Salter’s prerequisites are met, the results of a Salter osteotomy are known to be poor in this particular group of patients.
At the time of operation, the mean age of the 13 patients who underwent Chiari osteotomy was 9 years 4 months. The osteotomy was performed early in the disease process, before femoral head deformity had occurred. The hip was considered to be at risk because of the relatively late onset of the disease. Measurements were made on the preoperative and latest follow-up X-rays, and on the preoperative arthrogram. Patients were followed up for a mean of 3 years 4 months. On the preoperative arthrogram there was no femoral head deformity or hinging on abduction. At the time of surgery, it was too early to assign a hip reliably to a particular lateral or Herring lateral pillar group. However, during the follow-up period, 12 of the hips manifested as Catterall group IV and one as Catterall group II. Further, 11 hips advanced to become lateral pillar type B, and two to become lateral pillar type C. At follow-up, nine hips could be reliably graded according to the Stulberg classification: five were Stulberg type II and four Stulberg type III. It was clear that none of the remaining hips would be Stulberg type IV or V.
The Chiari osteotomy achieves a congruent hip in a specific group of patients where a poor outcome would otherwise be anticipated.
The abstracts were edited by Prof. M.B.E. Sweet. Correspondence should be addressed to him at the Department of Orthopaedic Surgery, Medical School, University of the Witwatersrand, 7 York Road, Parktown, 2193 South Africa
