Twelve to Twenty-year Follow-up of Dega Acetabuloplasty in Patients With Developmental Dysplasia of the Hip: Is it as Effective as Expected?

Background: Although Dega acetabuloplasty is widely used for the treatment of developmental dysplasia of the hip, there is a paucity of data on long-term outcomes. The purpose of the study was to evaluate the rate of residual acetabular dysplasia after Dega acetabuloplasty.Methods: Patients of a previously reported consecutive series of 35 patients (43 hips) operated by a single surgeon were recontacted for long-term follow-up. Of these, 25 patients (32 hips) consented, with a follow-up rate of 71% (74% of hips). The mean age at the time of surgery was 35 (18 to 65) months. The presence of residual dysplasia was noted according to the lateral center-edge angle of Wiberg, femoral head extrusion index, and Tonnis angle. The latest radiographic outcome was evaluated according to the Severin classification and patients were clinically evaluated according to the modified McKay criteria.Results: The mean follow-up duration of 16.5 (12 to 20) years yielded an average age of 19.2 (14 to 23) years at the time of analysis. According to lateral center-edge angle, femoral head extrusion index, and Tonnis angle, 5 (15.6%) hips were dysplastic and 2 (6.3%) hips were reoperated for resubluxation. Thus, a total of 7 hips (21.9%) were considered to have residual dysplasia. With the exception of 2 hips that underwent further osteotomies, no other hips were re-subluxated or redislocated. Overcoverage was noted in 6 (18.7%) hips. There were 26 Severin group I and II (81.3%), 4 Severin group III (12.5%), and 2 Severin group IV (6.2%) hips. According to modified McKay criteria, 20 (62.5%) hips were excellent, 7 (21.9%) hips were good, and 5 (15.6%) were fair. Severin classification and modified McKay criteria were correlated with dysplasia (P < 0.05).Conclusions: Seventy-eight percent of the hips treated by Dega acetabuloplasty for developmental dysplasia of the hip did not have acetabular dysplasia at a mean follow-up of 16 years. Even in well-treated asymptomatic hips, patients should be followed regularly, especially for residual dysplasia.Level of Evidence: Level IV.