BACKGROUND

Developmental dysplasia of the hip (DDH) is considered to have genetic predisposition and presents many intrafamilial occurrences. However, there is no report that evaluates the effect of DDH family history on the progression after the onset of hip osteoarthritis (OA).

METHODS

Medical interviews about detailed clinical information including family history were conducted on 298 consecutive patients who had undergone surgery for OA due to DDH. Clinical or radiographic items that are associated with the severity of DDH (total hip arthroplasty [THA], involvement of bilateral DDH, onset age of hip pain, and three radiological indices of DDH: center-edge angle, sharp angle, and acetabular roof obliquity) were collected and evaluated in multivariate analyses for their associations with DDH family history in a qualitative or quantitative manner. Survival time analyses for THA as the endpoint was also performed to evaluate the effects of DDH family history on the progression of OA.

RESULTS

The DDH family history showed significant associations with bilateral involvement of DDH (odds ratio = 2.09 [95% confidence interval {CI} 1.05 to 4.16]; P = .037), early onset of hip pain (P = .0065), and radiological severity of DDH (P = .016). The DDH family history showed a significant association with undergoing THA (odds ratio = 2.25 [95% CI 1.09 to 4.66]; P = .029), further supported by the Cox regression analyses (hazards ratio = 1.56 [95% CI 1.15 to 2.11]; P = .0044).

CONCLUSION

A DDH family history is a risk factor for the progression of hip OA. Stronger genetic predisposition to DDH leads to faster onset and progression of hip OA.