Diagnosing suspected scaphoid fractures: a systematic review and meta-analysis

Abstract

Imaging protocols for suspected scaphoid fractures among investigators and hospitals are markedly inconsistent. We performed a systematic review and meta-analysis to assess and compare the diagnostic performance of bone scintigraphy, MRI, and CT for diagnosing suspected scaphoid fractures. Twenty-six studies were included. Sensitivity, specificity, and diagnostic odds ratio were pooled separately and summary receiver operating characteristic curves were fitted for each modality. Meta-regression analyses were performed to compare these modalities. We obtained likelihood ratios derived from the pooled sensitivity and specificity and, using Bayes' theorem, calculated the posttest probability by application of the tests. The pooled sensitivity, specificity, natural logarithm of the diagnostic odds ratio, and the positive and negative likelihood ratios were, respectively, 97%, 89%, 4.78, 8.82, and 0.03 for bone scintigraphy; 96%, 99%, 6.60, 96, and 0.04 for MRI; and 93%, 99%, 6.11, 93, and 0.07 for CT. Bone scintigraphy and MRI have equally high sensitivity and high diagnostic value for excluding scaphoid fracture; however, MRI is more specific and better for confirming scaphoid fracture. We believe additional studies are needed to assess diagnostic performance of CT, especially paired design studies or randomized controlled trials to compare CT with MRI or bone scintigraphy.

Level of evidence: Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Fig. 1

A flowchart shows the results of the literature search and selection for this systematic review. The computer search yielded 2440 citations; 26 studies ultimately were included.

Fig. 2

The pooled sensitivity for bone scintigraphy was 97% (95% CI, 93%–99%) for bone scintigraphy, 96% (95% CI, 91%–99%) for MRI, and 93% (95% CI, 83%–98%) for CT.

Fig. 3

The pooled specificity for bone scintigraphy was 89% (95% CI, 83%–94%) for bone scintigraphy, 99% (95% CI, 96%–100%) for MRI, and 99% (95% CI, 96%–100%) for CT.

Fig. 4

The pooled ln DOR was 4.78 (95% CI, 4.02–5.54) for bone scintigraphy, 6.60 (95% CI, 5.43–7.76) for MRI, and 6.11 (95% CI, 4.56–7.66) for CT.

Fig. 5

A Galbraith plot for specificity of studies describing bone scintigraphy identified four outlier studies.

Fig. 6

The SROC curve for MRI was closest to the left upper corner, followed by CT and bone scintigraphy, indicating MRI had the highest overall diagnostic performance, then CT and bone scintigraphy.

Fig. 7A–C

(A) In patients with low pretest probability, positive results with bone scintigraphy cannot accurately confirm fracture, but negative results can accurately exclude fracture. (B) In patients with low pretest probability, positive results with MRI can reliably confirm fracture; negative results can accurately exclude fracture. (C) In patients with low pretest probability, positive results with CT can reliably confirm fracture; negative results can accurately exclude fracture.