A new clinical sign to detect radiologically occult greater tuberosity fractures.

Abstract

Up to 59% of undisplaced greater tuberosity (GT) fractures are missed on initial evaluation. Timely diagnosis of these injuries can avoid undue morbidity, but a clinical sign to accurately identify them has not previously been described. Magnetic resonance imaging (MRI) remains the gold standard for their assessment but may not be routinely available, or difficult to organize urgently. We aimed to evaluate the diagnostic efficacy of a new clinical sign (the anterior bruise sign [ABS]), in diagnosing radiologically occult GT fractures. Over a 4-year period, 59 patients who sustained a traumatic shoulder injury with no fracture on initial radiographs were referred to a specialist shoulder clinic within a week of their injury and enrolled in a prospective observational cohort study. At initial presentation, the presence of anterior arm bruising extending to the mid-diaphysis was recorded as a positive ABS. MRI assessment of the injured shoulder was performed in all patients at first follow-up. Presenting radiographs, 2-week radiographs, and MRI scans were reviewed by a musculoskeletal radiologist. The diagnostic value of a positive ABS was compared with 2-week radiographs, and other clinical tests. The mean age of the cohort was 58.5 (range 30-79) years, and 27 (45.8%) were female. The mean time from injury to first follow-up was 6.9 (standard deviation 2.4) days. MRI revealed that 25 of 59 patients (42.4%) had an undisplaced GT fracture. The overall accuracy of the ABS in identifying occult GT fractures was 98% (sensitivity = 100%, specificity = 97%, positive predictive value = 96%, negative predictive value = 100%, P < .001). In contrast, radiographs taken at 2 weeks postinjury were less accurate (71.2%) (P < .001), and other clinical assessments of cuff function had much lower accuracy. In patients presenting with a traumatic shoulder injury with normal radiographs, the ABS is a highly sensitive and specific clinical aid to identify patients with an occult GT fracture.