Trochanteric spurs and surface irregularities on plain radiography are not predictive of greater trochanteric pain syndrome

PURPOSE: Surface irregularities of the greater trochanter have been described as a potential radiographic sign of greater trochanteric pain syndrome (GTPS). We report a diagnostic accuracy study to evaluate the clinical usefulness of trochanteric surface irregularities on plain radiographs in the diagnosis of GTPS. METHODS: We retrospectively identified the anteroposterior pelvic radiographs of a consecutive group of 38 patients (representing a 27.5% series prevalence) diagnosed with GTPS (mean age 69.5 years ± 16.1 [standard deviation], 27 females, 11 males) based on clinical symptoms and a positive response to a local anaesthetic and steroid injection. A control group consisted of 100 patients (mean age 73 years ± 17.1 [standard deviation], 67 females, 33 males) with either hip osteoarthritis listed for hip arthroplasty ( n = 50), or with an intracapsular neck of femur fracture ( n = 50) both presenting between January and July 2017. Radiographs were cropped to blind observers to the presence of hip osteoarthritis or intracapsular fracture but included the trochanteric region. The radiograph sequence was randomised and separately presented to 3 orthopaedic surgeons to evaluate the presence of trochanteric surface irregularities. RESULTS: The inter-observer correlation coefficient agreement was acceptable at 0.75 (95% CI, 0.60-0.84). Trochanteric surface irregularities including frank spurs protruding ⩾2 mm were associated with a 24.7% positive predictive value, 64.0% sensitivity, 25.7% specificity, 74.3% false-positive rate, 36.0% false-negative rate, and a 65.3% negative predictive value for clinical GTPS. CONCLUSION: Surface irregularities of the greater trochanter are not reliable radiographic indicators for the diagnosis of greater trochanteric pain syndrome.