Ultrasonography for Rotator Cuff Tears

Summary

A Cochrane review [Abstract] 1 included 20 studies of people with suspected rotator cuff tears (1 147 shoulders), of which 6 evaluated magnetic resonance imaging (MRI) and ultrasonography (US) (252 shoulders), or magnetic resonance arthrography (MRA) and US (127 shoulders) in the same people. Meta-analyses were not possible for studies that assessed MRA for detection of any rotator cuff tears or partial thickness tears because there were few studies and considerable heterogeneity in estimates of sensitivity or specificity. There were 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). The summary sensitivities and specificities are shown in table T1.Because few studies were direct head-to-head comparisons, meta-analyses restricted to these studies could not be performed. The test comparisons for each of the three classifications of the target condition were therefore based on indirect comparisons.

Another systematic review 2 evaluated the evidence for the effectiveness and cost-effectiveness of the newer diagnostic imaging tests as an addition to clinical examination and patient history for the diagnosis of soft tissue shoulder disorders. Studies were identified that evaluated clinical examination, ultrasound, magnetic resonance imaging (MRI), or magnetic resonance arthrography (MRA) in patients suspected of having soft tissue shoulder disorders. Outcomes assessed were clinical impingement syndrome or rotator cuff tear (full, partial or any). Only cohort studies were included.

In the included studies, the prevalence of rotator cuff disorders was generally high, partial verification of patients was common and in many cases patients who were selected retrospectively because they had undergone the reference test. Sample sizes were generally very small. Reference tests were often inappropriate with many studies using arthrography alone, despite problems with its sensitivity.

Ultrasound was investigated in 38 cohort studies and found to be most accurate when used for the detection of full-thickness tears; sensitivity was lower for detection of partial-thickness tears. For MRI, 29 cohort studies were included. For full-thickness tears, overall pooled sensitivities and specificities were fairly high and the studies were not statistically heterogeneous; however for the detection of partial-thickness rotator cuff tears, the pooled sensitivity estimate was much lower. The results from six MRA studies suggested that it may be very accurate for detection of full-thickness rotator cuff tears, although its performance for the detection of partial-thickness tears was less consistent. Direct evidence for the performance of one test compared with another is very limited. The results suggest that clinical examination by specialists can rule out the presence of a rotator cuff tear, and that either MRI or ultrasound could equally be used for detection of full-thickness rotator cuff tears, although ultrasound may be better at picking up partial tears. Ultrasound also may be more cost-effective in a specialist hospital setting for identification of full-thickness tears.

Clinical comments

The diagnostic performance of MRI and US depends on the extent (i.e. partial or full thickness) of rotator cuff tears. A sensitivity of 52% suggests that US may not be any better than chance for detecting partial thickness rotator cuff tears. As the scope of this review was to limited to test accuracy, it was not possible to determine if applying any imaging test prior to surgery results in different surgical interventions or benefits in terms of pain relief and shoulder function following surgery.