Functional Results of Arthroscopic Treatment in Patients With Femoroacetabular and Subspine Impingement Diagnosed With a 3-Dimensional Dynamic Study

PURPOSE: To describe the functional results of arthroscopic treatment in patients with femoroacetabular impingement (FAI) and subspine impingement (SSI) evaluated with a 3-dimensional (3D) dynamic study. METHODS: This was a retrospective observational study of patients with a diagnosis of FAI and SSI, evaluated with a 3D dynamic computed tomography scan with Move Forward software, who underwent hip arthroscopy between February 2015 and December 2017. Measurements of the alpha angle, femoral anteversion, acetabular anteversion, lateral center-edge angle, and Tönnis angle were extracted from the 3D dynamic study. Functionality was evaluated using the Western Ontario McMaster Universities Osteoarthritis Index before and 12 months after surgery. RESULTS: We analyzed 22 hips in 17 patients (9 female and 8 male patients) with an average age of 34.6 ± 14.3 years. Of the 22 hips, 15 had cam morphology, 6 had mixed morphology, and 1 had pincer morphology. Of the hips, 11 had a type I spine, 10 had type II, and 1 had type III. The average alpha angle, Tönnis angle, femoral anteversion, and acetabular anteversion were 61.9° ± 11.1°, 2.5° ± 6.4°, 8.8° ± 6.8°, and 15.1° ± 7.1°, respectively. The median lateral center-edge angle was 38.1° (interquartile range, 32.6°-43.5°). At 1-year follow-up, a decrease in the Western Ontario McMaster Universities Osteoarthritis Index score (P = .001) and an increase in the flexion angle (P < .001) were observed. No cases needed posterior surgical revision because of persistent pain. CONCLUSIONS: Arthroscopic treatment provides symptom relief and good functional results in patients with FAI and SSI. LEVEL OF EVIDENCE: Level IV, therapeutic case series.