Iliopsoas impingement: a newly identified cause of labral pathology in the hip

Abstract

Labral tears typically occur anterosuperiorly in association with femoroacetabular impingement or dysplasia. Less commonly, labral pathology may occur in an atypical direct anterior location adjacent to the iliopsoas tendon in the absence of bony abnormalities. We hypothesize that this pattern of injury is related to compression or traction on the anterior capsulo-labral complex by the iliopsoas tendon where it crosses the acetabular rim. In a retrospective review of prospectively collected data, we identified 25 patients that underwent isolated, primary, unilateral iliopsoas release and presented for at least 1 year follow-up (mean 21 months). Pre-operative demographics, clinical presentation, intra-operative findings, and outcome questionnaires were analyzed. The injury was treated with a tenotomy of the iliopsoas tendon at the level of the joint line and either labral debridement or repair. Mean post-operative outcome scores were 87.17, 92.46, and 78.8 for the modified Harris Hip Score, activities of daily living Hip Outcome Score, and sports-related score, respectively. The atypical labral injury identified in this study appears to represent a distinct pathological entity, psoas impingement, with an etiology which has not been previously described.

Keywords: hip arthroscopy; labral tears; psoas impingement.

Fig. 1

Arthroscopic image demonstrating the iliopsoas impingement sign with labral inflammation (white arrow)

Fig. 2

Arthroscopic image after capsulotomy for visualization of the iliopsoas tendon (white arrow capsular window)

Fig. 3

Arthroscopic image demonstrating inflammation of the iliopsoas tendon (white arrow)

Fig. 4

Arthroscopic image demonstrating an intimate association among the labrum (black arrow), capsule (white arrow), and iliopsoas tendon (white arrowhead)

Fig. 5

Arthroscopic image after release of the iliopsoas tendon which now only demonstrates the labrum (black arrowhead) and capsule (white arrow) because the iliopsoas tendon has retracted