The Added Value of Postoperative Axial Imaging in Developmental Dysplasia of the Hip

BACKGROUND: Redislocation is a dreaded complication after reduction of developmental dysplasia of the hip (DDH) in young children. While early detection facilitates urgent reoperation, delayed revisions are more complicated. Despite the weak evidence, an axial postoperative imaging tool is recommended. This study’s goal is to compare the effectiveness of conventional pelvic radiography alone and axial imaging. METHODS: Data were collected retrospectively between 2012 and 2016. One study group comprised consecutive patients who had operative reduction followed by routine low-dose computed tomography (CT). Hips that had anteroposterior pelvic radiographs as the only confirmatory tool were used as a reference group. RESULTS: We identified 241 patients (339 hips). The mean age and follow up were 19.6 months ± 9.3, and 15.5 months ± 11.1, respectively. There were 147 hips in the radiography group and 192 in the CT group. Radiography detected only three out of nine redislocations during the same admission; in contrast, 2/2 redislocations in the routine CT group were addressed before hospital discharge (p<0.01). There was no significant delay in hospital discharge when CT was used (p= 0.28). CONCLUSION: Conventional radiography is not as effective as axial imaging in preventing late detection of redislocation. LEVEL OF EVIDENCE: level III, Diagnostic Study.