Association between periacetabular osteotomy and hip dysplasia among relatives: a cross-sectional study.

Introduction: Previous studies indicate a familial predisposition for developmental dysplasia of the hip (DDH), especially among first-degree relatives. This study investigated the association between unilateral or bilateral periacetabular osteotomy (PAO), family history of DDH and the degree of relationship with relatives with DDH.

Material And Methods: This cross-sectional study consisted of 815 consecutive patients undergoing PAO from 1998 to 2016. Information regarding unilateral or bilateral PAO, gender and age at the time of surgery was obtained from the clinical PAO database at Aarhus University Hospital, Denmark. A questionnaire was used to collect information about the family history of DDH. The association was assessed by logistic regression analysis, and divided into 615 unilateral and 200 bilateral PAO patients.

Results: PAO patients with a first-degree relative with DDH had a 72% (odds ratio [OR] = 1.72, 95% confidence interval [CI] 1.17; 2.50) higher occurrence of bilateral PAO than patients without family relatives with DDH. This association was statistically significant ( = 0.005), even when adjusting for gender and age at the time of surgery. A similar association was not demonstrated among any other degrees of relationship.

Conclusion: Danish patients with DDH and a first-degree relative with DDH have an increased risk of being surgically treated with bilateral PAO compared to patients without a family history of DDH. Patients undergoing bilateral PAO may therefore have a strong genetic predisposition for DDH. This study reveals a potential group of patients with DDH where genetic analysis may identify relatives with a higher risk of the disease.