Abstract
Introduction
While arthroscopic surgery for femoroacetabular impingement (FAI) effectively reduces pain and improves function, optimal rehabilitation strategies remain unclear. In particular, the relationship between changes in physical function and patient-reported outcomes during the early postoperative period has not been established. This study examined the association between changes in physical function and score on the 12-item International Hip Outcome Tool in Japanese (iHOT-12J) after FAI surgery.
Methods
We retrospectively evaluated 41 patients (12 men, 29 Women; mean age, 43.6±14.1 years) who underwent unilateral arthroscopic labral repair for FAI between June 2022 and June 2023. Hip range of motion (ROM; flexion, extension, abduction, adduction, internal rotation, external rotation), muscle strength (flexion, extension, abduction), the Flexion-Abduction-External Rotation Distance Test (FDT), 10-m walking speed (comfortable and maximum), and iHOT-12J were assessed preoperatively and at 3 months postoperatively. Paired t-tests or Wilcoxon's signed-rank tests were used to compare pre- and postoperative values.
Changes from preoperative to postoperative assessments were calculated for each parameter, and Spearman’s rank correlation coefficients were used to analyze the associations between these changes in iHOT-12J scores and changes in physical function parameters.
Results
Significant postoperative improvements were observed in hip ROM, specifically in operative-side flexion, bilateral extension, and operative-side adduction (p<0.05). Muscle strength significantly improved in bilateral hip flexion, nonoperative-side extension, and bilateral hip abduction (p<0.05). Operative-side FDT also significantly improved (21.4±7.7° → 18.3±7.1°, p=0.01). In addition, iHOT-12J scores showed marked improvement (39.5±22.3 → 68.0±24.5, p<0.01), and comfortable 10-meter walking speed increased (0.98±0.45 m/s → 0.85±0.18 m/s, p=0.01). Significant correlations with changes in iHOT-12J were found for operative hip abduction strength (ρ=0.432, p=0.012), nonoperative hip abduction strength (ρ=0.361, p=0.039), and operative hip flexion strength (ρ=0.351, p=0.046). No significant correlations were observed between iHOT-12J changes and ROM or walking speed.
Conclusion
Improvement in iHOT-12J scores at 3 months post-FAI surgery was associated with recovery of hip abduction and flexion strength, but not with ROM or gait speed.
These findings suggest that early postoperative rehabilitation focusing on strengthening periarticular hip muscles may be beneficial.