Utility of clinical tests to diagnose MRI-confirmed gluteal tendinopathy in patients presenting with lateral hip pain.
Grimaldi A., Mellor R., Nicolson P., Hodges P., Bennell K., Vicenzino B.
PURPOSE: Gluteal tendinopathy (GT) is a source of lateral hip pain, yet common clinical diagnostic tests have limited validity. Patients with GT are often misdiagnosed, resulting in inappropriate management, including surgery. This study determined the diagnostic utility of clinical tests for GT, using MRI as the reference standard. METHODS: 65 participants with lateral hip pain were examined to evaluate the ability of clinical tests to detect MRI-determined GT (an increase in intratendinous signal intensity on T2-weighted images). Palpation of the greater trochanter and several clinical pain provocation tests applying compressive and tensile loads on the gluteal tendons were investigated. MRI of the painful hip was examined by a radiologist, blind to clinical findings. RESULTS: Pain reported within 30 s of standing on the affected limb conclusively moves a (nominal) 50% pretest probability of GT presence on MRI to a post-test probability of 98% (specificity 100%, positive likelihood ratio ∼12), whereas no pain on palpation (80% sensitivity) would rule out its presence. 20 participants (31%) had GT on MRI but clinically negative (ie, not positive on palpation and another test). CONCLUSIONS: Keeping in mind that the sample size was small (ie, possibly underpowered for indices of diagnostic utility with low precision), the results of this study indicate that a patient who reports lateral hip pain within 30 s of single-leg-standing is very likely to have GT. Patients with lateral hip pain who are not palpably tender over the greater trochanter are unlikely to have MRI-detected GT.