The high osteotomy cut of Dega procedure for developmental dysplasia of the hip in children under 6 years of age

Dega osteotomy has gained popularity for the acetabular reconstruction of developmental dysplasia of the hip (DDH). A high-level Dega osteotomy combining the typical Dega procedure with an age limit of under 6 years and the higher pelvic cut height of the Salter osteotomy for walking DDH patients aged 6 or younger was advocated in our department. The purpose of this retrospective study is to introduce this modified Dega procedure and report the preliminary clinical and radiological results in DDH patients under 6. From September 2000 to September 2010, a total of 162 patients with 191 dysplastic hips between 1.5 and 6 years old were managed with this high-level Dega osteotomy. From each patient's record, clinical status was retrospectively assessed using modified McKay criteria; radiological evaluations were assessed according to the modified Severin classification, the mean acetabular index (AI), Sharp angle and center-edge (CE) angle. Any occurrence of complications was recorded postoperatively. The average age at surgery was 3.6 years (range 1.5 to 6.0), mean duration of follow-up 11.3 years (range 5.0 to 16.9). The latest follow-up fineness (favorable and good) rate in clinical and radiological evaluations was 92.7 % and 91.1 % respectively. There was a marked trend toward normalization of radiographic indices during the follow-up period: the mean AI changed from 38.0A degrees to 20.8A degrees, the mean Sharp's angle decreased from 59.9A degrees to 39.2A degrees, and the mean CE angle increased from -10.7A degrees to 29.4A degrees, preoperatively and at the latest follow-up respectively. No major complications were recorded during follow-up. The high osteotomy cut Dega procedure for patients between 1.5 and 6 years of age was found to be sufficient for improving clinical and radiographic outcomes and inducing little morbidity and few complications for late-detected pediatric walking DDH patients.