Which clinical features best predict occult scaphoid fractures? A systematic review of diagnostic test accuracy studies

Plain radiographs cannot identify all scaphoid fractures; thus ED patients with a clinical suspicion of scaphoid injury often undergo immobilisation despite normal imaging. This study determined (1) the prevalence of scaphoid fracture among patients with a clinical suspicion of scaphoid injury with normal radiographs and (2) whether clinical features can identify patients that do not require immobilisation and further imaging. This systematic review of diagnostic test accuracy studies included all study designs that evaluated predictors of scaphoid fracture among patients with normal initial radiographs. Quality assessment was undertaken using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Meta-analyses included all studies. Eight studies reported data on 1685 wrist injuries. The prevalence of scaphoid fracture despite normal radiographs was 9.0%. Most studies were at overall low risk of bias but two were at unclear risk; all eight were at low risk for applicability concerns. The most accurate clinical predictors of occult scaphoid fracture were pain when the examiner moved the wrist from a pronated to a supinated position against resistance (sensitivity 100%, specificity 97.9%, LR+ 45.0, 95% CI 6.5 to 312.5), supination strength <10% of contralateral side (sensitivity 84.6%, specificity 76.9%, LR+ 3.7, 95% CI 2.2 to 6.1), pain on ulnar deviation (sensitivity 55.2%, specificity 76.4%, LR+ 2.3, 95% CI 1.8 to 3.0) and pronation strength