Endoscopic Tendon Release for Iliopsoas Impingement after Total Hip Arthroplasty - Excellent Clinical Outcomes and Low Failure Rates at Short-Term Follow-up

PURPOSE: To investigate the clinical effectiveness of endoscopic IPR (iliopsoas tendon release) at the LT (lesser trochanter) in patients with IPI (iliopsoas impingement) after THA (total hip arthroplasty).

METHODS: Between November 2017 and March 2021, a consecutive series of 36 patients were treated with endoscopic IPR for diagnosed IPI. Patients included had acetabular cup position confirmed by functional imaging (OPSTM, Corin, Pymble, NSW), typical clinical symptoms of IPI and a positive response to diagnostic injection. Clinical assessment included validated patient-reported outcome measures (PROMs) along with hip flexion strength and active range of motion at different time-marks up to 2-year follow-up, as well as surgical complications.

RESULTS: Overall, 36 consecutive patients (11 males) with a mean age of 62±12 years were included. All patients had failed non-operative management. Dynamic CT assessment was available in 89% of the patients, edge loading was reported in 10% and variable cup overhang in 50%. Clinically, PROMs were significantly improved at every time-mark when compared with preoperative values (p<0.001), showing the biggest improvement within the first 4 weeks after surgery. At 6-months follow-up, peak isometric hip flexion strength on the operated side was 20% lower than the contralateral side (p<0.001). Failure rate of the procedure was 2.8% (1 case). Linear regression showed no association between cup overhang and clinical outcomes.

CONCLUSIONS: Endoscopic IPR at the LT is a safe and reproducible technique associated with significant and immediate improvement in pain, functional outcomes and high patient satisfaction. With minimal short-term weakness, no complications and only a single revision even in cases with cup malposition and/or edge loading, we believe that endoscopic IPR can be considered as one of the first line operative options in patients with symptomatic IPI, irrespective of component position.