Treatment of severe late onset Perthes' disease with soft tissue release and articulated hip distraction: early results.

Sixteen children with late onset Perthes' disease were surgically treated at an average age of 12 years 1 month (9 years 4 months to 15 years) by soft tissue release and articulated hip distraction. Two patients had additional diagnosis of Down syndrome and one suffered from geleophysic epiphyseal dysplasia. Fifteen hips were graded Catterall IV and Herring C and one hip was graded Catterall III Herring B. On preoperative arthrograms, 14 patients had a saddle-shape subluxating femoral head with hinge abduction. The distraction discontinued when Shenton line was corrected. The fixation lasted 4-5 months. At a mean follow-up of 2 years 7 months (1-5 years), an improvement of hip range of motion was found in all patients. Hip joint arthrograms upon removal of the fixator showed disappearance of the saddle-shape femoral head in 10 of the 14 patients with this deformation. Shenton line breakage improved from 7.6 mm to 2.1 mm at last follow-up. The epiphyseal index improved by 14%. The average pain score on an analog scale dropped from a preoperative 7.0 to 1.6 at last follow-up (filled in by patients or parents in case of Down syndrome). Separate analysis of data from the group having only Perthes disease (13 children) showed better results. These preliminary data suggest that soft tissue release combined with unloading of the femoral head and restoration of joint space can improve the function and epiphyseal height.