Can subcoracoid effusion be a more specific finding for subscapularis tear among rotator cuff pathologies on magnetic resonance imaging?

HYPOTHESIS AND BACKGROUND

Magnetic resonance imaging (MRI) is a well-known, noninvasive diagnostic method for rotator cuff tendon pathologies that are not very sensitive for subscapularis tendon tears. Subcoracoid effusion (SE) is an easily recognizable radiologic sign on MRI. In this study, we aimed to examine the relationship of SE with rotator cuff tear and to investigate whether SE could be a supportive finding in the diagnosis of subscapularis tear in preoperative MRI. Our hypothesis was that SE was a more specific finding of subscapularis tear than other rotator cuff tears.

METHODS

The data of patients who underwent shoulder arthroscopy in our clinic between 2017 and 2021 were analyzed retrospectively. Four groups were included in the study: patients with a rotator cuff tear accompanied by a subscapularis tear (group 1, n = 273), patients with isolated subscapularis tear (group 2, n = 57), patients with rotator cuff tear with intact subscapularis tendon (group 3, n = 190), and patients without any rotator cuff pathology (group 4, n = 263). Arthroscopic video records and MRIs of all patients were evaluated retrospectively. Subscapularis tendon tears were classified according to the Lafosse classification.

RESULTS

There was a statistically significant difference between the groups in terms of the presence of SE on MRI (P = .001). The presence of SE in group 1 and group 2 was statistically significantly higher than that in both group 3 and group 4 (P = .001), and there was no significant difference between group 3 and group 4 (P > .05). A significant relationship was found between Lafosse classification and SE (P = .001). When the diagnostic powers of the detection of SSC tear and the presence of SE on MRI for SSC tear were compared, Kappa values were 0.615 (P = .001) and 0.701 (P = .001), and overall diagnostic accuracy rates were 80.3% and 85.5%, respectively.

CONCLUSION

We conclude that SE is a more specific finding for subscapularis tears than other rotator cuff pathologies. We suggest that SE on MRI should also be considered in patients with a rotator cuff tear in whom a subscapularis tear was not detected in preoperative MRI and that the subscapularis tendon should be carefully evaluated during surgery in cases where the effusion is positive.