MRA for SLAP – Is the Threshold for Referral Too Low?

Background: Superior labrum anterior to posterior (SLAP) lesions are a clinically important cause of shoulder pain and instability.

Many clinical tests are used to diagnose labral and SLAP lesions, however, the diagnostic accuracy of these tests is relatively low, unspecific and often inferior to imaging.

MRA has been reported to be superior to conventional MRI for detecting glenoid labral tears, particularly SLAP however it is more invasive and costly.

The aim of this study is to evaluate the use of MRA when a clinical diagnosis of SLAP is suspected.

Methods: A retrospective clinical trial of 95 patients, 53 females and 42 males, that underwent shoulder MRA for the evaluation of SLAP in the Sheba medical center between 1.3.2012 and 1.5.2017. The patient’s data and referral cause were taken from the referral letter. All MRIs had been reviewed by an expert in musculoskeletal radiology.

Results: A SLAP lesion was found in 28 cases (29.5%) and was the most common finding in males with 16 cases (38.1%). However, SLAP was only found in 12 females (22.6%) and the most common finding in the female subgroup was no pathology at all (24.5%).

A half of the cases that were positive for SLAP had other concomitant shoulder pathologies. 75.8% of all cases had other shoulder pathologies with or without SLAP.

A relatively high incidence of labrum tear, adhesive capsulitis, rotator cuff and glenohumeral ligament tears was found, with 17, 11, 11 and 10 cases respectfully.

Conclusion: The threshold for the use of MRA as an aid for clinical diagnosis of SLAP may be too low. MRA is a limited resource that entails increased potential risks in comparison to MRI and therefore its use should be more closely monitored.