Age at time of surgery alone may not predict outcomes after periacetabular osteotomy: Study

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. HOOSglobal is a recently validated patient reported outcome (PRO) measure following PAO.

Hence, Brian T. Muffly and associates from the University of Kentucky Department of Orthopaedic Surgery & Sports Medicine, USA conducted the study asses HOOSglobal and WOMAC scores at early follow-up based on age at the time of Periacetabular osteotomy.

The authors conducted a prospective multicenter cohort including a total of 391 patients undergoing PAO with minimum 2-year follow-up (average, 4.71 years). Patients were categorized into 4 age groups: <20 years (N=131), 20-29 (N=102), 30-39 (N=65), and ≥40 (N=34).

A 4x2 repeated measures analysis of variance (ANOVA; Age Group x Time) was used to compare pre- and postoperative HOOSglobal and WOMAC scores between age groups. A multiple linear regression was used to identify predictors of postoperative HOOSglobal scores.

The results showed that –

1. 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<0.002), 20-29 (p=0.01), and 30-39 (p=0.02).
2. Higher preoperative HOOSglobal scores were predictive of greater postoperative HOOSglobal scores (p<0.001) but age (p=0.65), sex (p=0.80), BMI (p=0.50), and To¨nnis Classification (p=0.07) were not independent predictors of one-year outcomes.

Therefore, the authors concluded that "the absence of differences in early post-operative PROs 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 Periacetabular osteotomy, they further added.