Do the Functional Results of Surgical Treatment of Patients with Neglected Developmentally Dislocated Hips Remain the Same with Longer Follow-Up?

Abstract

Background: The results of treatment for neglected developmental dysplasia of the hips (DDH) in children remains controversial. We sought to determine the clinical and radiographic result of patients with neglected DDH with special emphasis on the functional outcome as determined by the Pediatric Outcomes Data Collection Instrument (PODCI) and determine which preoperative variables were related to the result. We also sought to determine if the functional results remain the same over time and if there is there a preoperative variable that can predict a poor outcome.

Methods: This was a retrospective review of 15 patients (19 hips, 11 unilateral and 4 bilateral) treated after the age of 6 years (mean: 7.6 years) with one stage open reduction, femoral shortening, and innominate osteotomy with a minimum follow-up of 15 years. Clinical and radiographic evaluations were performed at 10 years and 15 years after the index procedure. Functional outcome was determined using the PODCI scale and the Iowa Hip Score; the radiographic result was evaluated with the Severin classification, the center-edge angle, and the Tönnis grade of osteoarthritis. Linear regression analysis was used to determine the influence of preoperative variables on the result.

Results: The patients were evaluated at two points in time: the first evaluation was performed at a mean 10.7 years after surgery (range: 10.0 to 12.2 years); at that time, the patients mean age was 17.8 years; 11 had pain and 14 had a limp, the mean Iowa hip score was 73.5 and the mean PODCI score was 88.05. The mean CE angle was 26.9°, one hip was considered a Severin type I, six as type II, eight as type III, and four as type IV; eight hips were considered Tönnis grade I, seven grade II, and four grade III. The second evaluation was performed at a mean 15.8 years after surgery (range: 15.1 to 17.3 years); at that time, the patients mean age was 22.9 years; 14 had pain and 14 had a limp, the mean Iowa hip score was 67.8, and the mean PODCI score was 85.73. The mean CE angle was 29.7°, one hip was considered a Severin type I, four as type II, 10 as type III, and four as type IV; two hips were considered Tönnis grade I, five grade II, nine grade III, and three grade IV. The results were significantly worse than those seen at the first evaluation. Linear regression analysis showed a tendency toward worse functional and radiographic results with increasing age at the time of treatment as well as with time of follow-up.

Conclusions: The results demonstrate a directly inverse relationship between age at the time of treatment and functional and radiographic results for patients with neglected DDH. A progressive deterioration of the results with further follow-up was also found.