Physical examination tests in the acute phase of shoulder injuries with negative radiographs: a diagnostic accuracy study.

BACKGROUND

Rotator cuff tears may easily be missed in patients with acute shoulder trauma. The evidence in support of shoulder physical examination tests has been considered insufficient in reviews and meta-analyses. The purpose of this study was to explore whether physical examination tests can effectively predict or rule out acute full-thickness rotator cuff tears in soft tissue shoulder injuries in emergency departments and primary health care.

METHODS

In a combined primary care walk-in clinic and secondary care orthopaedic emergency department, 120 consecutive patients aged ≥ 40 years with acute shoulder injury without fracture on plain x-rays were enrolled prospectively at the first follow-up within three weeks of the injury. Thirteen physical examination tests and ultrasound screening as reference standard, were performed blinded to each other.

RESULTS

The median age was 55 years, 51% were female. The prevalence of the target condition rotator cuff full-thickness tear and/or occult fracture of the insertion was 38% (n = 46; 38 tears and 8 occult avulsion fractures). Almost all tears involved the supraspinatus tendon (n = 36). The highest test accuracy was observed for the inability to abduct above 90°, resisted abduction pain and external rotation strength. The sensitivity, specificity and diagnostic odds ratio of the inability to abduct the arm above 90 ° was 84% (95% CI 69-93), 71% (95% CI 59-82) and 12.9 (95% CI 4.8-34.2), respectively, and 66% (51-80), 86% (77-93) and 12.4 (5.0-30.8) for external rotation strength assessed by the small finger test. Combining the inability to abduct above 90° and weakness in external rotation improved the sensitivity to above 90% and the diagnostic odds ratio to above 22, but specificity decreased.

CONCLUSIONS

The present study suggests that two simple tests, the inability to abduct above 90° and weakness in external rotation may effectively predict full-thickness tears of the supra- and infraspinatus and/or occult fracture at their insertion in the acute phase of soft tissue shoulder injuries. The test combination may be useful for selecting patients for advanced imaging and for diagnostic purposes when such imaging is not available.

TRIAL REGISTRATION

The Norwegian Regional Ethics Committee South East (2015/195) on 24th March 2015, and retrospectively registered on ClinicalTrials.gov (NCT02644564) on 31st December 2015.