Article Text
Abstract
Introduction Gluteal tendinopathy (GT) has been increasingly recognised as a source of lateral hip pain. Soft tissue pathology at the greater trochanter may co-exist with, or mimic referred pain from the lumbar spine or hip joint osteoarthritis. Previous studies have reported that patients with GT are commonly misdiagnosed, resulting in inappropriate management, including unnecessary spinal investigations and surgical procedures.1 Available literature on accurate clinical diagnosis of symptomatic GT is inadequate. A recent meta-analysis reported that tests for lateral hip pain generally have weak diagnostic properties.2 This study aimed to determine the diagnostic utility of clinical tests for gluteal tendinopathy, using MRI as the reference standard.
Methods Sixty participants (age (mean ± SD) 54 ± 9 years, BMI 28.2 ± 5 kg/m2) reporting lateral hip pain were recruited. A battery of clinical tests were performed to determine a positive or negative clinical diagnosis of GT. Participants were then referred for MRI evaluation of their gluteal tendons and hip (blinded to clinical results). The clinical tests included passive hip flexion to 90°/ adduction to end of range (EOR)/ external rotation (ER) (i.e. FADER), FADER with static resisted hip internal rotation (FADER-R), hip flexion/abduction/ER (FABER), passive EOR hip adduction in sidelying (ADD), ADD with static resisted abduction at EOR (ADDR), and palpation of the greater trochanter. A clinical diagnosis of GT (CDGT) was defined as tenderness on palpation, plus at least one other positive (reproduction of pain) from the remaining tests. A series of contingency tables were generated and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated and used as indices of diagnostic utility for the clinical screen (i.e., positive = palpation and one other physical test) as well as each individual physical test. The reference standard was the MRI results (GT findings: positive or negative).
Results Palpation over the greater trochanter was the most sensitive clinical test for GT diagnosed on MRI (BUT ALSO THE LEAST SPECIFIC), whereas an abduction contraction in ADD was most specific and had highest sensitivity (Table 1). All tests show high positive predictive value and remarkably lower negative predictive value when compared to MRI diagnosed GT.
Discussion Our data indicate that in terms of an MRI diagnosed GT, a patient presenting with lateral hip pain who is not tender on palpation over the greater trochanter laterally will most likely not have tendinopathy. Resisted abduction in end of range adduction in sidelying exhibits greatest diagnostic utility (positive likelihood ratio = 5.9), followed by FADER-R. Interestingly, the clinical tests involving static muscle contraction are most specific.
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