Closed Reduction for Developmental Dysplasia of the Hip: Early-term Results From a Prospective, Multicenter Cohort

Abstract

Background: Closed reduction (CR) is a common treatment for infantile developmental dysplasia of the hip. The purpose of this observational, prospective, multicenter study was to determine the early outcomes following CR.

Methods: Prospectively collected data from an international multicenter study group was analyzed for patients treated from 2010 to 2014. Baseline demographics, clinical exam, radiographic/ultrasonographic data, and history of previous orthotic treatment were assessed. At minimum 1-year follow-up, failure was defined as an IHDI grade 3 or 4 hip and/or need for open reduction. The incidence of avascular necrosis (AVN), residual dysplasia, and need for further surgery was assessed.

Results: A total of 78 patients undergoing CR for 87 hips were evaluated with a median age at initial reduction of 8 months (range, 1 to 20 mo). Of these, 8 hips (9%) were unable to be closed reduced initially. At most recent follow-up (median 22 mo; range, 12 to 36 mo), 72/79 initially successful CRs (91%) remained stable. The likelihood of failure was unaffected by initial clinical reducibility of the hip (P=0.434), age at initial CR (P=0.897), or previous treatment in brace (P=0.222). Excluding those hips that failed initial CR, 18/72 hips (25%) developed AVN, and the risk of osteonecrosis was unaffected by prereduction reducibility of the hip (P=0.586), age at CR (P=0.745), presence of an ossific nucleus (P=0.496), or previous treatment in brace (P=0.662). Mean acetabular index on most recent radiographs was 25 degrees (±6 degrees), and was also unaffected by any of the above variables. During the follow-up period, 8/72 successfully closed reduced hips (11%) underwent acetabular and/or femoral osteotomy for residual dysplasia.

Conclusions: Following an initially successful CR, 9% of hips failed reduction and 25% developed radiographic AVN at early-term follow-up. History of femoral head reducibility, previous orthotic bracing, and age at CR did not correlate with success or chances of developing AVN. Further follow-up of this prospective, multicenter cohort will be necessary to establish definitive success and complication rates following CR for infantile developmental dysplasia of the hip.

Level of evidence: Level II-prospective observational cohort.

FIGURE 1

CONSORT (Consolidated Standards of Reporting Trials) diagram showing patients evaluated, excluded, and enrolled by stage, along with primary and secondary outcomes at latest radiographic follow-up.

FIGURE 2

A, AP view of the right hip demonstrating a normal-appearing hip 36 months following closed reduction. B, AP view of the right hip demonstrating epiphyseal fragmentation 23 months following closed reduction, which was classified as AVN. C, AP view of the left hip 18 months following closed reduction demonstrating absence of the ossific nucleus and broadening of the femoral neck, which was also classified as AVN. AP indicates anteroposterior; AVN, avascular necrosis.