Preoperative muscle weakness is a risk factor for persistent pain 1 year after hip arthroscopy for femoroacetabular impingement syndrome.

Abstract

Background: Femoroacetabular impingement syndrome (FAIS) is a common condition causing hip and groin pain. Hip arthroscopy has been established as a viable treatment option when nonoperative management fails to relieve symptoms of FAIS. Despite the numerous positive hip arthroscopy outcomes for FAIS, some individuals experience persistent postoperative pain. Preoperative muscle strength may be associated with persistent pain and function after arthroscopy in patients with FAIS; however, further investigation is necessary to confirm this theory.

Objective: To determine the effect of preoperative muscle strength on persistent pain after arthroscopy in patients with FAIS.

Design: Retrospective single-institution cohort study.

Setting: Tertiary care university hospital in Japan.

Participants: Seventy-eight patients who underwent hip arthroscopy for FAIS between December 2015 and September 2021.

Methods: Data were collected on patient demographics, preoperative hip abductor and quadriceps strength, preoperative and postoperative visual analog scale (VAS) for pain, and postoperative patient-reported outcomes (PRO). Hip abductor and quadriceps strength were assessed only on the affected side using a hand-held dynamometer. The VAS uses a 100 mm horizontal line to assess pain intensity, with higher values indicating greater pain. PRO was assessed using the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) score.

Interventions: Not applicable.

Main outcome measure: VAS score for pain 1 year postoperatively.

Results: Of the 78 patients, 16 (20.5%) had persistent pain (VAS ≥30) 1 year postoperatively. Low preoperative hip abductor and quadriceps strength were associated with persistent pain after arthroscopy even after adjusting for age, gender, and preoperative VAS score (p = .021 and p = .030, respectively). Low preoperative hip abductor and quadriceps strength were associated with lower JHEQ scores 1 year postoperatively even after adjustments (p = .020 and p = .001, respectively).

Conclusions: In these patients, low preoperative muscle strength compared with normal muscle strength was a risk factor for persistent pain and poor PRO scores 1 year postoperatively.