Iliopsoas release in hip arthroscopy: Assessment of muscle atrophy

Iliopsoas release is a common procedure for coxa saltans interna of the hip. The possible sequelae from this surgery have not been well studied. The purpose of this study was to determine postoperative atrophy and morphology of the cut tendon. This retrospective review included patients who underwent arthroscopic iliopsoas release and had magnetic resonance imaging of the ipsilateral hip before and after surgical intervention. Cross-sectional area measurements were obtained of the iliopsoas muscle at the level of the distal anterior inferior iliac spine as well as at the L5 vertebral pedicle in patients who had imaging that included the lower lumbar spine. Patient-reported outcomes included the modified Harris Hip Score (mHHS) and the Hip Outcome Score subscales for activities of daily living (HOS ADL) and sport (HOS Sport). A total of 44 patients met inclusion criteria for this study; 26 patients had additional advanced imaging that included the lumbar spine. The cross-sectional area of the iliopsoas at the level of the anterior inferior iliac spine decreased postoperatively by a mean of 191.4 mm^2;, this difference was statistically significant (P<.0001). Mean area at the L5 pedicle was 628.9 mm² on the released side and 1216.2 mm² on the nonoperative side (P<.05). Mean Goutallier-Fuchs score of the released iliopsoas at the L5 pedicle was 1.3 (SD, 0.7). Mean mHHS, HOS ADL, and HOS Sport scores for patients at least 1 year postoperatively were 51, 56, and 42, respectively.