Endoscopic gluteus maximus tendon release for external snapping hip syndrome: a functional assessment

Purpose: The aim of this retrospective study was to investigate the clinical follow-up of patients with external snapping hip syndrome (ESHS) treated with endoscopic gluteus maximus tendon release and to compare the residual muscular strength and thigh circumference as an indirect outcome measure. Methods: Patients of all ages with external snapping hip syndrome were treated with endoscopic gluteus maximus tendon release. Outcome measures evaluated included: visual analog scale (VAS), modified Harris Hip Score (mHHS), and Non-Arthritic Hip Score (NAHS). The gluteus maximus strength and the circumference of the thigh were also evaluated. Results: Among 25 patients, 23 fulfilled the inclusion criteria and one patient was lost to follow-up. The series included 22 patients, 6 males and 16 females with a mean age of 27.9 ± 13.4 years (range 16–76 years). All patients had resolution of the snapping symptoms after the procedure. The mean follow-up was 18 ± 9.3 months. All outcomes improved in a statistically significant manner: VAS value decreased from 6.8 (range 6–8) to 0.6 (range 0–4) (p < 0.001), mHHS increased from 48.6 (range 17.6–67) to 88.2 (range 67–94.6) (p < 0.001), NAHS increased from 49.0 (range 21.5–66) to 90.8 (range 66–98.75) (p < 0.001). A statistically significant reduction of operated limb thigh circumference compared to the contralateral side (3.7%) was also found, while there were no statistical differences regarding the strength of gluteus maximus muscles. Conclusions: Endoscopic gluteus maximus tendon release is an excellent surgical option to treat snapping hip syndrome. The evaluated muscle strength revealed no functional impairment. The significance of the limb circumference reduction has yet to be determined. Level of evidence: IV: retrospective comparative trial.