Hip Arthroscopy Followed by 6-Month Rehabilitation Leads to Improved Periarticular Muscle Strength, Except for Abductors and External Rotators

Abstract

Purpose: To evaluate the variations in hip muscles strength following arthroscopy and 6-month rehabilitation in patients treated for femoroacetabular impingement (FAI). Methods: A retrospective analysis was carried out on a series of patients who were arthroscopically treated for FAI at La Tour Hospital between 2020 and 2022. Bilateral isometric strengths of 8 hip-related muscles (abductors, adductors, hamstrings, quadriceps, extensors, flexors, internal and external rotators) were assessed using a handheld dynamometer before surgery and postoperatively after 6 months of rehabilitation in terms of relative strength changes between time points. Results: A total of 29 patients (aged 26.9 ± 7.1 years, 86% of women) were included. Except for the abductors, which remained of comparable strength than before surgery, a statistically significant (P < .05) increase in hip muscle strength on the operated side could be noted at 6 postoperative months for hamstrings (9% ± 17%, P = .041), quadriceps (11% ± 27%, P = .045), extensors (17% ± 32%, P = .006), flexors (17% ± 29%, P = .003), adductors (18% ± 23%, P < .001), and internal rotators (32% ± 36%, P < .001). The proportion of patients who reached a strength level above their preoperative status ranged from 62% (quadriceps) to 86% (adductors and flexors), depending on the muscle studied. The external rotators were the only muscles that remained significantly weakened at 6 months on both operated (–13% ± 26%, P = .002) and nonoperated (–17% ± 25%, P < .001) sides, with a decrease beyond 15% in almost half of the patients (45% and 48%, respectively). Conclusions: Arthroscopic treatment followed by 6-month rehabilitation granted to most FAI patients a higher strength level for several hip muscles, except for abductors and external rotators, which remained comparable and weakened, respectively. Level of Evidence: Level IV, therapeutic case series.