Change in Muscle Volume in Patients With Unilateral Femoro-acetabular Impingement Syndrome After Hip Arthroscopy

Inclusion Criteria: * (1) Age 18-50 years; (2) symptoms, physical examination, imaging evidence in accordance with FAI; (3) symptoms that were not alleviated by nonsurgical treatment; (4) the operation is performed by the same senior operator. Exclusion Criteria: * (1) bilateral symptoms; (2) revision surgery; (3) advanced osteoarthritis; (4) acetabular dysplasia; (5) history of hip and knee joint disease and operation; (6) osteonecrosis of hip; (7) sacroiliac joint disease