, Volume 23, Issue 3, pp 855-860
Date: 22 Sep 2012

Kinematic shoulder MRI: the diagnostic value in acute shoulder dislocations

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Objectives

To determine whether positioning of the arm in adduction and internal rotation would improve the confidence in the diagnosis of Bankart lesions in first time shoulder dislocators.

Methods

Eleven patients were imaged on an open bore MRI within 1–6 days of traumatic shoulder dislocation with the arm adducted and internally rotated, and subsequently the patients were reimaged with the arm adduced and externally rotated. Two blinded musculoskeletal radiologists determined the confidence of diagnosing labral tears in each of the two positions.

Results

An anterior–inferior labral tear was diagnosed in 11/11 patients in internal rotation and in 6/11 patients in external rotation. The average confidence was 2.8 in internal rotation and 1.5 in external rotation (on a scale of 0–3). Using a Wilcoxon signed rank test, the certainty of the diagnosis was determined to be significantly higher with the arm in internal rotation (P = 0.016).

Conclusions

MRI performed with the arm in internal rotation for patients with acute first time anterior shoulder dislocation increases the certainty of the diagnosis of anterior–inferior labral tears.

Key Points

Adduction and internal arm rotation improves the MRI diagnosis of Bankart tears.

Arm positioning in ADIR has distinct advantages over abduction and external rotation.

Early imaging after shoulder dislocation may provide a diagnostically useful “arthrographic” effect.