Endoscopic Tenotomy for Iliopsoas Tendinopathy Following Total Hip Arthroplasty Can Relieve Pain Regardless of Acetabular Cup Overhang or Anteversion

Abstract

To report outcomes of endoscopic iliopsoas tenotomy (EIT) in patients with iliopsoas tendinopathy following total hip arthroplasty (THA) and determine whether improvements in clinical scores are associated with acetabular cup anteversion measured on plain radiographs or overhang measured using established and alternative computed tomography (CT)-based methods. We evaluated patients who underwent EIT for iliopsoas tendinopathy after THA (2014-2017), performed between the lesser trochanter and psoas valley. Indications were groin pain during active hip flexion, exclusion of other complications, and no pain relief after 6 months of conservative treatment. Pretenotomy inclination and anteversion were measured on radiographs; sagittal and axial overhang were measured on CT scans on slices passing through: (Method 1) prosthetic head center and (Method 2) anterior margin of acetabular cup. Modified Harris hip score (mHHS), Oxford Hip Score (OHS), and level of groin pain were recorded at 12 or more months. Wilcoxon signed-rank tests were used to compare pre- and post-tenotomy scores, and intraclass correlation coefficients (ICCs) to assess intermethod agreement. The cohort comprised 16 men (17 hips) and 32 women (33 hips), aged 60.8 ± 10.5 years at EIT. For the 30 (60%) hips that had pretenotomy CT scans, axial and sagittal overhang were, respectively, 3.4 ± 3.7 mm and 4.6 ± 4.6 mm, using Method 1, compared with 3.9 ± 3.9 mm and 6.9 ± 5.0 mm using Method 2. Intermethod agreement was good for axial (ICC, 0.67; P < .001) and sagittal (ICC, 0.68; P < .001) overhang. At a minimum 1 year after EIT, 3 hips had cup and stem revision and 1 hip had isolated cup revision, leaving 46 hips for clinical assessment. No complications were noted. mHHS improved by 26 ± 19 (P < .001) and OHS improved by 20 ± 11 (P < .001). Twenty-six hips (57%) achieved the patient acceptable symptom state for mHHS, whereas 42 hips (91%) achieved the patient acceptable symptom state for OHS. Post-tenotomy groin pain was slight in 15%, mild in 17%, and moderate in 11%. Regression analyses revealed no associations between clinical scores and overhang/anteversion. For patients with iliopsoas tendinopathy following THA, endoscopic iliopsoas tenotomy granted clinically important improvements of mHHS in 76% and OHS in 89%, despite moderate residual groin pain in 11%. Improvements in clinical scores did not seem to be associated with the extent of cup overhang or anteversion in the cases for which adequate preoperative imaging was available. Level IV, retrospective cohort study.