Is varus osteotomy necessary in one-stage treatment of developmental dislocation of the hip in older children?

Innominate osteotomy, varisation–derotation osteotomy, and shortening osteotomy are the most common surgical procedures used to achieve pelvifemoral realignment in the treatment of children over three years of age with developmental hip dislocation. It is well known that varus osteotomy can improve the acetabular index but it does have some disadvantages. The aim of this study was to discuss the results obtained with patients treated only with Salter osteotomy, derotation osteotomy, and shortening, without varus osteotomy, and to evaluate the need for varisation on the basis of these results.

Between 1996 and 2001, twenty-four hips, sixteen unilateral and four bilateral, of a total of twenty patients treated with this method and available for final controls were evaluated. The study included sixteen female and four male patients with a mean age of 4 years 2 months (ranging between 2 years 10 months and 8 years). The mean follow-up period was determined as 6.57 years (range 5–10 years). McKay’s clinical criteria, Sever’s radiological criteria, and the evaluation system modified by Trevor et al. were used for evaluation of the results.

Based on McKay’s clinical criteria, eighteen hips (75%) were classified as type I, four hips (16%) as type II, and two hips (9%) as type III. According to Sever’s radiological criteria, thirteen hips (54%) were graded as grade I, nine hips (37.5%) as grade II, and two (8.5%) as grade III. According to the modified evaluation system of Trevor et al. the results were categorized as excellent in thirteen hips, good in nine hips, and moderate in two hips. Pre-operative mean acetabular index was measured as 37.3° (28°–50°) and early post-operative mean acetabular index as 26° (18°–38°). In the final radiological examination the mean acetabular index was measured as 18.3° and the mean CE angle as 30.1° (15°–38°). Avascular necrosis affecting the results developed in five hips.

It is concluded that in older children with developmental dislocation of the hip (DDH) treated with one-stage combined surgical intervention, adequately stable concentric reduction can be achieved without varisation and that varus osteotomy is not always necessary.