Objective To investigate the clinical efficacy of modified arthroscopic revision release for patients who have gluteal muscle contracture and who have poor outcomes after traditional open surgery.

Methods The data of patients who underwent modified arthroscopic revision release for residual symptoms of gluteal muscle contracture after traditional open surgery were retrospectively collected and analyzed. All subjects underwent the procedure between December 2015 and December 2022. The surgical efficacy was assessed by evaluating improvements in specific symptoms, including bilateral lower extremity inequality, hip internal rotation and adduction mobility, squatting with both knees pressed together, and the ability to cross one's legs in supine position, as well as the preoperative and postoperative results for the gluteal muscle contracture functionality scale. Paired t-test was performed to examine whether the differences between preoperative and postoperative measurements were statistically significant.

Results A total of 36 patients were followed up systematically, with the mean follow-up period being (22.4±4.9) months. All patients had significantly higher scores for assessment with the gluteal muscle contracture functionality scale at the last follow-up than their preoperative assessment results, showing an increase from the preoperative scores of 40.2±5.5 to 78.4±4.9 (P<0.05). At the follow-up, all patients showed improvement in hip adduction and internal rotation mobility compared with their preoperative status and all patients were able to squat with both knees pressed together. Moreover, only 1 patient still had difficulty in crossing his legs. A total of 27 cases (75%) had preoperative leg length inequality, all of which improved to varying degrees at follow-up. Among all the patients (72 hips/cases), 8 cases had subcutaneous hematomas and incisional ecchymosis, which were resolved after conservative treatments such as hot compresses. 3 cases showed decreased hip abductor strength, but the muscle strength gradually recovered after postoperative exercise and rehabilitation. There were no complications such as subcutaneous exudate, neurovascular injury, or surgical site infection.

Conclusion Modified arthroscopic revision release of gluteus muscle contracture is suitable for cases with poor outcomes after conventional open surgery.