Results after arthroscopic treatment of iliopsoas impingement after total hip arthroplasty.

ABSTRACT

BACKGROUND: A cause of groin pain after total hip arthroplasty (THA) is mechanical irritation or impingement of the iliopsoas tendon. The incidence is about 4%. If conservative therapy fails, an arthroscopic release of the iliopsoas tendon can be performed. The aim of the study was to assess the mid-term clinical outcome after arthroscopic release. We hypothesize that good results can be achieved by a minimally invasive endoscopic procedure. METHODS: Using our in-house database, all patients who received an endoscopic release of the iliopsoas tendon due to mechanical irritation after THA were identified. Inclusion criteria were mechanical irritation of the iliopsoas tendon after cementless THA with minimal acetabular component prominence. Exclusion criteria were marked prominence of the acetabular component and groin pain after THA for any other reason. In these patients, the modified Harris Hip Score (mHHS), the pain level using the numerical analogue scale and the UCLA Activity Score were measured. The mean follow-up period was 7 ± 3.8 (2.6-11.7) years. RESULTS: 25 patients were identified in whom an arthroscopic release of the iliopsoas tendon had been performed since 2007. The data of 20 patients were available at follow-up. The gender ratio was 11, the average age at the time of arthroscopy was 59 ± 27.7 (52-78) years. The average interval between THA and arthroscopy was 6.3 ± 4.0 (1.7-15) years. The mHHS showed a significant improvement from preoperative 31.2 ± 9.8 (17.6-47.3) to 82.0 ± 9.8 (46.2-100) points (p = 0.001). The pain level on the NAS decreased significantly from 8.5 ± 1.2 (7-10) to 2.5 ± 1.8 (0-6) points (p = 0.001). The activity level based on the UCLA Activity Score raised from 4.0 ± 2.7 (0-7) to 6.5 ± 1.8 (3-9) (p = 0.09). CONCLUSION: Mechanical irritation and impingement of the iliopsoas tendon is an important diagnosis to be considered in persistent groin pain after total hip arthroplasty. In failure of non-operative treatment, good clinical results can be achieved with arthroscopic release and the pain level can be significantly reduced. LEVEL OF EVIDENCE IV.