Risk Factors for Iliopsoas Tendinopathy After Anterior Approach Total Hip Arthroplasty.

Background: Iliopsoas tendinopathy is a cause of groin pain following total hip arthroplasty (THA). With the anterior approach becoming increasingly popular, our aim was to determine the prevalence of iliopsoas tendinopathy following anterior approach THA, to identify risk factors and to determine an influence on patient-reported outcomes.

Methods: This is a retrospective case-control study of prospectively recorded data on 2,120 primary anterior approach THA (1,815 patients). The diagnosis of iliopsoas tendinopathy was based on (1) persistent postoperative groin pain, triggered by hip flexion; (2) absence of dislocation, infection, loosening, or fracture; and (3) decrease of pain after fluoroscopy-guided iliopsoas tendon sheet injection with xylocaine and corticosteroid. Outcomes included hip reconstruction (inclination/anteversion and leg-length), complication rates, reoperation rates, and patient-reported outcomes including Hip disability and Osteoarthritis Outcome Score.

Results: Forty four patients (46 THAs) (2.2%) were diagnosed with iliopsoas tendinopathy. They were younger than patients who did not have iliopsoas tendinopathy (51 years [range, 27-76] versus 62 years [range, 20-90]; P < .001). Logistic regression analyses demonstrated that younger age (P < .001) and presence of a spine fusion (P = .008) (odds ratio 4.6) were the significant predictors of iliopsoas tendinopathy. These patients had lower Hip disability and Osteoarthritis Outcome scores, reported more often low back pain (odds ratio 4.8), and greater trochanter pain (odds ratio 5.4).

Conclusion: We found an incidence of 2.2% of iliopsoas tendinopathy patients after anterior approach THA that compromised outcomes. Younger age and previous spine fusion were identified as most important risk factors. These patients were 5 times more likely to report low back pain and greater trochanter pain post-THA.