Clinical outcomes after arthroscopic psoas lengthening: the effect of femoral version

The purpose of this study was to examine the association between femoral anteversion and clinical outcomes after arthroscopic lengthening of a symptomatic, snapping psoas tendon in young patients.

Sixty-seven consecutive patients with symptomatic coxa saltans underwent arthroscopic psoas tendon lengthening through a transcapsular approach during a 3-year period by a single arthroscopic hip surgeon. Demographic and clinical variables were collected. Patients were divided into low/normal femoral version and high femoral version groups and analyzed for association of femoral version with clinical outcomes as measured by the modified Harris Hip Score (mHHS) and Hip Outcome Score (HOS) preoperatively and postoperatively with a minimum of 6 months' follow-up (range, 6 to 24 months). Two-sample t tests were used for data analysis, with P < .05 defined as significant.

Preoperative evaluation showed excessive anteversion (>25°) associated with worse HOS sports subscale scores (26.6 v 50.0 for excessive v low/normal anteversion, P = .013) and no difference in mHHS and HOS activities-of-daily living subscale scores. Postoperative mHHS scores were significantly different (76.9 v 86.1 for excessive v low/normal anteversion, P = .031). No association was noted between clinical outcome measures and any other clinical or demographic variable (P > .05).

Patients with increased femoral anteversion may be at greater risk for inferior clinical outcomes after arthroscopic lengthening of a symptomatic, snapping psoas tendon. The psoas tendon may be an important passive and dynamic stabilizer of the hip in these patients, and release may result in a greater alteration of kinematics with high-demand activities, particularly terminal extension and external rotation when the tendon is typically at its highest tension. These results may help surgeons identify which patients may be at risk for inferior clinical outcome after psoas lengthening.