Age at the Time of Surgery Is Not Predictive of Early Patient-Reported Outcomes After Periacetabular Osteotomy

Background: The clinical success of periacetabular osteotomy (PAO) for the treatment of symptomatic acetabular dysplasia is well-documented. Conflicting evidence exists regarding the correlation of age with clinical outcomes. Hip disability and Osteoarthritis Outcome Score - global (HOOSglobal) is a recently validated patient-reported outcome measure following PAO. The purpose of this study is to asses HOOSglobal and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores at early follow-up based on age at the time of PAO.

Methods: A prospective multicenter cohort of 391 patients undergoing PAO with minimum 2-year follow-up (average 4.71 years) were identified. Patients were categorized into 4 age groups: <20 years (N = 131), 20-29 (N = 102), 30-39 (N = 65), and ≥40 (N = 34). A 4 × 2 repeated measures analysis of variance (Age Group × Time) was used to compare preoperative and postoperative HOOSglobal and WOMAC scores between age groups. A multiple linear regression was used to identify predictors of postoperative HOOSglobal scores.

Results: HOOSglobal and WOMAC scores increased across all age groups; however, a statistically greater increase in preoperative to postoperative HOOSglobal and WOMAC scores was found in those ≥40 years compared to those <20 (P< .002), 20-29 (P = .01), and 30-39 years (P = .02). Higher preoperative HOOSglobal scores were predictive of greater postoperative HOOSglobal scores (P < .001) but age (P = .65), gender (P = .80), body mass index (P = .50), and Tönnis Classification (P = .07) were not independent predictors of 1-year outcomes.

Conclusion: The absence of differences in early postoperative patient-reported outcomes across multiple age ranges emphasizes that PAO in the setting of symptomatic acetabular dysplasia can be successful regardless of patient age alone. Therefore, age alone might not be an appropriate selection criterion when evaluating surgical candidates for PAO.

Level of evidence: II.