The effectiveness of ultrasound in the detection of fractures in adults with suspected upper or lower limb injury: a systematic review and subgroup meta-analysis.

Background: The aim of the present review is to assess the effectiveness of ultrasound (US) in the detection of upper and lower limb bone fractures in adults compared to a diagnostic gold standard available in secondary and tertiary care centres (e.g. radiography, CT scan or MRI).

Methods: The review followed PRISMA guidelines and used a database-specific search strategy with Medline, EMBASE and The Cochrane Library plus secondary sources (see supplementary material for completed PRISMA checklist). Diagnostic performance of ultrasound was assessed with a qualitative synthesis and a meta-analysis of two data subgroups.

Results: Twenty-six studies were included (n = 2360; fracture prevalence =5.3 % to 75.0%); data were organised into anatomical subgroups, two of which were subjected to meta-analysis. Sensitivity and specificity ranged from 42.11 - 100% and 65.0 - 100%, with the highest diagnostic accuracy in fractures of the foot and ankle. The pooled sensitivity and specificity of US was 0.93 and 0.92 for upper limb fractures (I = 54.7 % ; 66.3%), and 0.83 and 0.93 for lower limb fractures (I = 90.1 % ; 83.5%).

Conclusion: Ultrasonography demonstrates good diagnostic accuracy in the detection of upper and lower limb bone fractures in adults, especially in fractures of the foot and ankle. This is supported by pooled analysis of upper and lower limb fracture subgroups. Further research in larger populations is necessary to validate and strengthen the quality of the available evidence prior to recommending US as a first-line imaging modality for prehospital use.

Trial Registration: The protocol is registered with the PROSPERO International register of systematic reviews: ID =  CRD42017053640 .