What is the best way to diagnose a suspected rotator cuff tear?
Magnetic resonance arthrography (MRA), based on 6 cohort studies, may be accurate in the diagnosis of a full-thickness tear, with a sensitivity of 0.95 (95% CI, 0.82–0.98) and specificity of 0.93 (95% CI, 0.84–0.97).1 In these studies, diagnosis of partial-thickness tears with MRA was inconsistent.1 The invasiveness of MRA limits its utility as compared with MRI and ultrasound. The TABLE summarizes these findings.
TABLE
Summary of test characteristics of diagnostic studies for rotator cuff injuries
| DIAGNOSTIC STUDY | FULL-THICKNESS ROTATOR CUFF TEAR | PARTIAL-THICKNESS ROTATOR CUFF TEAR | ||||||
|---|---|---|---|---|---|---|---|---|
| SN | SP | LR+ | LR– | SN | SP | LR+ | LR– | |
| Clinical exam1 | 0.9 | 0.54 | 1.96 | 0.19 | Inconclusive due to small sample size | |||
| Ultrasound1 | 0.87 | 0.96 | 21.75 | 0.14 | 0.67 | 0.94 | 11.17 | 0.35 |
| MRI1 | 0.89 | 0.93 | 12.71 | 0.12 | 0.44 | 0.9 | 4.4 | 0.73 |
| Arthrography2 | 0.50 | 0.96 | 12.5 | 0.52 | Not evaluated | |||
| MR arthrography1 | 0.95 | 0.96 | 23.75 | 0.05 | Inconsistent test performance | |||
| Sn, sensitivity; Sp, specificity; LR+, positive likelihood ratio; LR–, negative likelihood ratio; MRI, magnetic resonance imaging. | ||||||||
Recommendations from others
The American Academy of Orthopaedic Surgeons has a clinical guideline on shoulder pain,4 and the Brigham and Women’s Hospital has a guide to the prevention, diagnosis and treatment of upper extremity musculoskeletal disorders.5 These guidelines emphasize the importance and utility of physical examination of the shoulder. A patient with a full-thickness tear will likely demonstrate compromised strength in shoulder active mid-arc abduction and resisted external rotation with elbow flexed at patient’s side. However, a partial tear might not compromise strength. Atrophy of the infraspinatus or supra-spinatus muscles is sometimes seen with a full-thickness tear that is several weeks old.5
Following a clinical assessment, the guidelines give no preference to any of the diagnostic tests mentioned above, with the exception of arthrography in the presence of implantable devices. Plain X-rays are typically unrevealing, but could be used to rule out other reasons for pain, such as calcific tendonitis.
