The goal of this clinical trial is to analyze the impact of perineal post-free traction versus traditional perineal post traction on perineal complications in hip arthroscopy. The main question it aims to answer is:

• Can Perineal Post-Free Traction in Hip Arthroscopy Effectively Reduce Perineal Complications? Researchers will compare the perineal-post-free traction group with the conventional perineal-post traction group to see if the former decreases perineal complications and improves efficiency without compromising surgical outcomes.

Participants will:

• Undergo either perineal-post-free or standard perineal-post traction during hip arthroscopy
• Complete nerve-injury checks on day 1 and at discharge, and hip-function questionnaires (VAS, mHHS, IHOT-12, HOS) at 3 months
• Allow collection of operating times, hospital stay, and direct medical costs for economic analysis

Inclusion Criteria:

• Aged 15 to 60 years;
• Met the diagnostic criteria of femoroacetabular impingement syndrome (FAI) and indicated for hip arthroscopy based on patient history, symptoms, signs, physical examination, imaging (pelvic anteroposterior view, frog-leg view, CT 3D reconstruction, MRI), and diagnostic injections;
• Able to read and sign the informed consent form.

Exclusion Criteria:

• History of high-energy hip trauma, previous ipsilateral or contralateral hip surgery, avascular necrosis of the femoral head, slipped capital femoral epiphysis, Perthes disease, severe osteoporosis, tumors, acetabular stress fractures, or proliferative or immune hip diseases;
• Diseases causing groin numbness, foot numbness, sexual dysfunction, urinary dysfunction, skin injuries, perineal injuries, nerve injuries, radicular pain, inner or outer thigh numbness;
• Abnormal heart, lung, liver, kidney function, severe coagulation disorders, poorly controlled diabetes, judged by the researcher to have an infection risk;
• Consciousness disorders, psychiatric disorders, or neuromuscular dysfunction affecting lower limb function;
• Active infection foci (systemic or local infectious lesions);
• Pregnancy, lactation, or planned pregnancy during the clinical study period;
• Participation in another clinical trial within the past 3 months;
• Patients deemed unsuitable for the clinical trial by the researcher for other reasons.

Individual participant data (IPD) will not be shared with external independent researchers. The original informed consent only permits internal study team, institutional ethics committee and regulatory authorities to access coded data for trial quality control, without explicit participant consent for sharing de-identified IPD for external secondary research. Full trial protocol, statistical analysis plan and analytic codes are available to eligible researchers for result replication upon reasonable request.