Surgical treatment of adolescent acetabular dysplasia with a periacetabular osteotomy: Does obesity increase the risk of complications?

Background: The Bernese periacetabular osteotomy (PAO) is frequently used to treat symptomatic acetabular dysplasia in the adolescent age group. Despite encouraging results, factors predictive of the development of postoperative complications remain poorly understood. The purpose of this study was to investigate whether obesity is a risk factor for complications following PAO in adolescents. Methods: A retrospective cohort study design was used to collect data from 3 different institutions. Children and adolescents (below 19 y of age) who underwent PAO and were followed for minimum of 12 months were included. Obesity was defined as a body mass index ≥95 percentile. The modified Clavien-Dindo classification was used to grade complications. A logistic regression analysis was used to identify factors related to the development of a complication that required treatment outside of routine postoperative care (complication grades II to V). Changes in radiographic parameters including Tönnis acetabular roof angle, anterior center-edge angle, and lateral centeredge angle among obese versus nonobese subjects were also evaluated. Results: The mean age at surgery among the 84 adolescents included in the study was 16.5 years (range, 12 to 19 y). A total of 11% of the population was considered obese. Obesity (P=0.0047) was the only variable significantly associated with the development of a complication. After controlling for study site, the odds of an obese subject developing a complication were 10 [95% confidence interval (CI), 1.89-59.8] times the odds of a nonobese subject developing a complication. There was no difference in the magnitude of change in anterior center-edge angle (P=0.1251), lateral center-edge angle (P=0.9774), or Tönnis (P=0.5770) angular correction that was achieved among the obese versus nonobese subjects following surgery. Conclusions: The Bernese PAO allows for adequate radiographic correction of acetabular dysplasia among obese and nonobese adolescents. However, the hip preservation surgeon should be aware of the higher risk of complications among obese adolescents undergoing PAO for the treatment of symptomatic acetabular dysplasia.