Two Novel Clinical Tests for the Diagnosis of Hip Labral Tears

Background: There are few well-studied clinical tests for the diagnosis of hip labral tears. As the differential diagnosis for hip pain is broad, accurate clinical examination is important in guiding advanced imaging and identifying patients who may benefit from surgical management. Purpose: To determine the diagnostic accuracy of 2 novel clinical tests for the diagnosis of hip labral tears. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Clinical examination findings including the Arlington, twist, and flexion-adduction-internal rotation (FADIR)/impingement tests as performed by a fellowship-trained orthopaedic surgeon specializing in hip arthroscopy were obtained from retrospective chart review. The Arlington test ranges the hip from flexion-abduction-external rotation to FADIR while applying subtle internal rotation and external rotation motion. The twist test involves internal rotation and external rotation of the hip while weightbearing. Diagnostic accuracy statistics for each of the tests were calculated using magnetic resonance arthrography as the reference standard. Results: A total of 283 patients were included in the study with a mean age of 40.7 years (range, 13-77 years) and 66.4% were women. The Arlington test was found to have a sensitivity of 0.94 (95% CI, 0.90-0.96), specificity of 0.33 (95% CI, 0.16-0.56), positive predictive value (PPV) of 0.95 (95% CI, 0.92-0.97), and negative predictive value (NPV) of 0.26 (95% CI, 0.13-0.46). The twist test was found to have a sensitivity of 0.68 (95% CI, 0.62-0.73), specificity of 0.72 (95% CI, 0.49-0.88), PPV of 0.97 (95% CI, 0.94-0.99), and NPV of 0.13 (95% CI, 0.08-0.21). The FADIR/impingement test was found to have a sensitivity of 0.43 (95% CI, 0.37-0.49), specificity of 0.56 (95% CI, 0.34-0.75), PPV of 0.93 (95% CI, 0.87-0.97), and NPV of 0.06 (95% CI, 0.03-0.11). The Arlington test was significantly more sensitive than both the twist and FADIR/impingement tests ( P < .05), while the twist test was significantly more specific than the Arlington test ( P < .05). Conclusion: The Arlington test is more sensitive than the traditional FADIR/impingement test, while the twist test is more specific than the FADIR/impingement test in diagnosing hip labral tears in the hands of an experienced orthopaedic surgeon.