Date: November 2, 2023
Reference: Coventry et al. Which clinical features best predict occult scaphoid fractures? A systematic review of diagnostic test accuracy studies. Emerg Med J. Aug 2023
Guest Skeptic: Dr. Matt Schmitz is an Orthopaedic Surgeon who sub-specializes in adolescent sports and hip preservation. He will soon be transitioning out of the US military after a 20-year career in the Air Force and is soon to be Clinical Professor of Orthopaedics at UC San Diego.
DISCLAIMER: THE VIEWS AND OPINIONS OF THIS BLOG AND PODCAST DO NOT REPRESENT THE UNITED STATES GOVERNMENT OR THE US MILITARY.
Case: A 24-year-old manual labourer presents to the emergency department (ED) after drinking a few too many beers, having a disagreement with another beer drinker and gets knocked down. The mechanism was described as a classic FOOSH (fall on outstretched hand) injury. Examination reveals pain along the wrist and in his anatomical snuffbox. However, the x-rays read as “normal” by radiology.
Background: Fractures of the scaphoid are the most common carpal fractures presenting to the ED. One of the best systematic reviews and meta-analyses on the topic discussing the diagnostic accuracy of the history, physical examination and imaging is by Carpenter et al from AEM 2014 [1]. We went into some detail on SGEM#385.
Many potential scaphoid fractures are immobilized but this can be a detriment to job, school, and activities of daily living. Initial Xray’s pick up only about 17% of fractures [2]. Having patients follow-up in a couple of weeks for repeat x-rays can pick up about 7% more [3].
MRIs have greater diagnostic accuracy [1] but may not be available in some areas and can be expensive and not always readily available. A CT scan is not as accurate as an MRI but does come with a different type of cost, radiation exposure [1].
Clinical Question: What to do with a patient who presents with a FOOSH injury and has a normal x-ray; are there clinical exam findings that can help rule in/rule out a scaphoid fracture?
Reference: Coventry et al. Which clinical features best predict occult scaphoid fractures? A systematic review of diagnostic test accuracy studies. Emerg Med J. Aug 2023
Population: Patients with a clinical suspicion of having a scaphoid fracture but a normal initial x-ray
Excluded: Studies that did not have enough information to create a 2x2 table even after contacting study authors.
Intervention: Various physical examination maneuvers
Comparison: N/A
Outcome: Diagnostic accuracy expressed as sensitivities, specificity, and likelihood ratios
Authors’ Conclusions: “No single feature satisfactorily excludes an occult scaphoid fracture. Further work should explore whether a combination of clinical features, possibly in conjunction with injury characteristics (such as mechanism) and a normal initial radiograph might exclude fracture. Pain on supination against resistance would benefit from external validation.”
Quality Checklist for Systematic Review Diagnostic Studies:
The diagnostic question is clinically relevant with an established criterion standard. Yes
The search for studies was detailed and exhaustive. Yes
The methodological quality of primary studies were assessed for common forms of diagnostic research bias. No
The assessment of studies were reproducible. Yes
There was low heterogeneity for estimates of sensitivity or specificity. No
6. The summary diagnostic accuracy is sufficiently precise to improve upon existing clinical decision-making models. No
Results: They searched the worlds literature, followed the PRISMA guidelines and found eight studies of which four included a small number of children. There were 1,685 wrist injuries included in the SRMA of which there were 123 (9%) occult scaphoid fractures (normal initial x-rays). Most studies were reported as having an overall low risk of bias.
