Diagnostic accuracy of imaging modalities for suspected scaphoid fractures

Abstract

Follow-up radiographs are usually used as the reference standard for the diagnosis of suspected scaphoid fractures. However, these are prone to errors in interpretation. We performed a meta-analysis of 30 clinical studies on the diagnosis of suspected scaphoid fractures, in which agreement data between any of follow-up radiographs, bone scintigraphy, magnetic resonance (MR) imaging, or CT could be obtained, and combined this with latent class analysis to infer the accuracy of these tests on the diagnosis of suspected scaphoid fractures in the absence of an established standard. The estimated sensitivity and specificity were respectively 91.1% and 99.8% for follow-up radiographs, 97.8% and 93.5% for bone scintigraphy, 97.7% and 99.8% for MRI, and 85.2% and 99.5% for CT. The results were generally robust in multiple sensitivity analyses. There was large between-study heterogeneity for the sensitivity of follow-up radiographs and CT, and imprecision about their sensitivity estimates. If we acknowledge the lack of a reference standard for diagnosing suspected scaphoid fractures, MRI is the most accurate test; follow-up radiographs and CT may be less sensitive, and bone scintigraphy less specific.

Adult Scaphoid Fracture

“…24 Two diagnostic meta-analyses have been published in the orthopedic surgery literature to evaluate advanced imaging modalities for scaphoid fracture, but none focus on history and physical examination diagnostic accuracy or ED-specific pretest probability, all necessary to facilitate Bayesian reasoning for bedside clinicians. 25,26 One consequence of the lack of a synopsis of all of these diagnostic estimates is interphysician inconsistency in selection and timing of more definitive imaging and post-ED management decisions. 27,28 The primary objective of this meta-analysis was to assess the pretest probability and pooled diagnostic test characteristics (sensitivity, specificity, and likelihood ratios [LRs]) for occult scaphoid fracture considering all relevant elements of the history and physical examination, as well as imaging tests that are available in the ED.…”

Imaging of Scaphoid Fractures According to the New S3 Guidelines

“…▶ by means of CT the fracture is detected with high sensitivity (85 to 95 %) and specificity (95 to 100 %) and is thus greater than in projection radiography (sensitivity by 70 %, specificity 70 % to 85 %) [9,12,13]. Cortical and trabecular disruptions are sensitively demonstrated in CT (• ▶ Fig.…”

“…The hyperintense bone marrow edema is a sensitive but unspecific sign of fracture to the scaphoid bone [12,13]. A distinction must be made among three post-injury situations with similar edema patterns, but with different therapeutic consequences.…”

“…The strength of MRI lies in detection of bone marrow edema which is detectable in fractures on the scaphoid with a sensitivity of about 100 % [12,13].…”

“…The utilization of three-phase scintigraphy is supported by the high negative predictive value after the third day post-injury, the high positive predictive value in the case of patients with an initial negative X-ray finding and simultaneous evidence of injury to the remaining bones of the hand [13,17,22]. Due to its poor spatial resolution and low specificity, positive findings in scintigraphy must always be supplemented by a subsequent CT and/or MRI diagnosis.…”