EP3.10 The Angel Hair Sign: Evaluation of an Arthroscopic Technique to Guide Cam Resection Without Fluoroscopy

Abstract Background Adequate femoral cam resection is a key determinant of successful hip arthroscopy for femoroacetabular impingement syndrome. Fluoroscopy is commonly used to guide femoral osteochondroplasty; however, its routine use is associated with radiation exposure for both patients and operating-room staff, as well as additional operative time required to obtain, adjust, and interpret repeated fluoroscopic images during cam correction. To address these limitations, we introduce the Angel Hair Sign, an arthroscopic visual landmark designed to identify the transition between the native femoral head-neck contour and the pathologic cam prominence. This sign may allow controlled and reproducible cam resection without fluoroscopic guidance during the osteochondroplasty phase. Purpose To evaluate the clinical outcomes of patients undergoing hip arthroscopy for cam-type femoroacetabular impingement using an Angel Hair Sign–guided femoral osteochondroplasty technique without intraoperative fluoroscopic guidance during cam resection. Methods A retrospective cohort of 110 patients who underwent hip arthroscopy for cam-type femoroacetabular impingement was analyzed. Femoral osteochondroplasty was performed using the Angel Hair Sign as the primary arthroscopic landmark to guide the starting point, extent, and endpoint of cam resection, without fluoroscopic guidance during the resection phase. Final correction was assessed through direct arthroscopic visualization and expanded dynamic intraoperative testing. Patient-reported outcomes were collected preoperatively, at 6 months, and at 12 months postoperatively. Outcome measures included the Hip and Groin Outcome Score, Non-Arthritic Hip Score, modified Harris Hip Score, International Hip Outcome Tool–12, hip pain, and quality-of-life scores. Longitudinal changes in clinical outcomes were evaluated across the three time points. Results Patients demonstrated progressive postoperative improvement in clinical outcome scores over the study period. Improvements were observed in hip-specific function, pain, and quality-of-life measures from the preoperative evaluation to postoperative follow-up. Recovery was evident at 6 months and was maintained or further improved at 12 months. The absence of fluoroscopic guidance during cam resection did not appear to compromise intraoperative assessment of femoral correction. By reducing the need for repeated fluoroscopic checks, the Angel Hair Sign–guided technique may also contribute to decreased operative time and a more streamlined surgical workflow. Conclusion Angel Hair Sign–guided cam resection during hip arthroscopy was associated with favorable short-term clinical improvement in 110 patients with cam-type femoroacetabular impingement. This technique may represent a reproducible arthroscopic strategy to guide femoral osteochondroplasty while reducing reliance on intraoperative fluoroscopy during the resection phase. In addition to limiting radiation exposure, this approach may improve surgical efficiency and reduce operative time.