Point-of-Care Ultrasound for Suspected Radiographically Occult Proximal Femoral Fracture in Adults With Acute Hip Pain: A Systematic Review of Diagnostic Accuracy Studies

Radiographically occult proximal femoral fracture is a recognised diagnostic hazard in acute care.Magnetic resonance imaging (MRI) is the reference standard but is rarely available at the bedside, and point-of-care ultrasound (POCUS) has been proposed as an adjunct that may modify clinical suspicion while advanced imaging is arranged.This systematic review aimed to identify and appraise primary studies of clinicianperformed hip ultrasound in adults presenting acutely with hip pain and suspected proximal femoral fracture with non-diagnostic or pending radiographs.PubMed/MEDLINE, Embase, Scopus, Web of Science, the Cochrane Library and trial registers were searched from inception to 1 September 2026, with citation searching.The review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and PRISMAdiagnostic test accuracy (PRISMA-DTA) and was not prospectively registered.Eligible studies were original peer-reviewed diagnostic accuracy studies using B-mode hip ultrasound against MRI, computed tomography (CT) or a composite reference standard; radiography was accepted only to confirm a visible fracture, never to classify a participant as fracture-negative.Two-by-two tables were reconstructed, exact binomial confidence intervals (CIs) were derived, and risk of bias was appraised with the Quality Assessment of Diagnostic Accuracy Studies, Version 2 (QUADAS-2).Pooling was not performed because of clinical and methodological heterogeneity.Four prospective studies (389 participants; 186 with proximal femoral fracture) were included.Only two restricted enrolment to radiograph-negative patients and verified all participants with MRI.Observed sensitivity ranged from 0.96 to 1.00, with lower CI bounds of 0.69-0.92.Specificity ranged from 0.65 to 0.99; the lowest values occurred with qualitative capsular signs and the highest with cortical discontinuity or a measured capsular threshold, but these were indirect comparisons confounded by setting, operator, population and reference standard.A hypothetical scenario analysis suggested that the largest study's sensitivity would fall to 0.89 if only 10 fractures had been missed among unverified excluded patients.Every study was at high or unclear risk of bias in at least one QUADAS-2 domain, and fracture-subtype-specific accuracy could not be reconstructed.Hip POCUS showed high observed sensitivity and variable specificity in small, heterogeneous and biased studies; these estimates should not be taken as its true performance in routine emergency practice.The evidence supports POCUS only as an adjunct that may modify suspicion and help prioritise CT or MRI, not as a rule-out test.Adequately powered emergency department studies with blinded emergency-clinician sonographers, prespecified criteria, subtype-specific reporting and universal MRI verification are needed.