Abstract: We included 20 studies of people with suspected rotator cuff tears (1147 shoulders), of which six evaluated MRI and US (252 shoulders), or MRA and US (127 shoulders) in the same people. Many studies had design flaws, with the potential for bias, thus limiting the reliability of their findings. Overall, the methodological quality of the studies was judged to be low or unclear. For each test, we observed considerable heterogeneity in study results, especially between studies that evaluated US for the detection of full thickness tears and studies that evaluated MRA for the detection of partial thickness tears. The criteria for a positive diagnostic test (index tests and reference standard) varied between studies. Meta-analyses were not possible for studies that assessed MRA for detection of any rotator cuff tears or partial thickness tears. We found no statistically significant differences in sensitivity or specificity between MRI and US for detecting any rotator cuff tears (P = 0.13), or for detecting partial thickness tears (P = 1.0). Similarly, for the comparison between MRI, MRA and US for detecting full thickness tears, there was no statistically significant difference in diagnostic performance (P = 0.7). For any rotator cuff tears, the summary sensitivity and specificity were 98% (95% CI 92% to 99%) and 79% (95% CI 68% to 87%) respectively for MRI (6 studies, 347 shoulders), and 91% (95% CI 83% to 95%) and 85% (95% CI 74% to 92%) respectively for US (13 studies, 854 shoulders). For full thickness tears, the summary sensitivity and specificity were 94% (95% CI 85% to 98%) and 93% (95% CI 83% to 97%) respectively for MRI (7 studies, 368 shoulders); 94% (95% CI 80% to 98%) and 92% (95% CI 83% to 97%) respectively for MRA (3 studies, 183 shoulders); and 92% (95% CI 82% to 96%) and 93% (95% CI 81% to 97%) respectively for US (10 studies, 729 shoulders). Because few studies were direct head-to-head comparisons, we could not perform meta-analyses restricted to these studies. The test comparisons for each of the three classifications of the target condition were therefore based on indirect comparisons which may be prone to bias due to confounding. MRI, MRA and US have good diagnostic accuracy and any of these tests could equally be used for detection of full thickness tears in people with shoulder pain for whom surgery is being considered. The diagnostic performance of MRI and US may be similar for detection of any rotator cuff tears. However, both MRI and US may have poor sensitivity for detecting partial thickness tears, and the sensitivity of US may be much lower than that of MRI. The strength of evidence for all test comparisons is limited because most studies were small, heterogeneous and methodologically flawed, and there were few comparative studies. Well designed studies that directly compare MRI, MRA and US for detection of rotator cuff tears are needed.

Plain-language summary: We searched electronic databases up to February 2011, as well as trial registers, conference proceedings and reference lists of articles, for studies comparing diagnostic tests for people with suspected rotator cuff tears. Our review included 20 studies (1147 shoulders). Many studies had design flaws, which limited the reliability of their findings. We found that MRI, MRA and US may have similar accuracy for detecting the presence of full thickness tears. For identifying any tears (no distinction between partial or full thickness) or identifying partial thickness tears, MRI and US may also have similar accuracy. However, it appears that compared with US, MRI may be more sensitive in identifying partial thickness tears. With these results we can conclude that all three imaging tests (MRI, MRA and US) may help decisions regarding referral for surgery for people with suspected full thickness tears. Information on adverse effects of using these tests was not reported by the included studies.