Natural History of Rotator Cuff Tears Monitored by Magnetic Resonance Imaging

Abstract

The present study was conducted to evaluate the natural history of rotator cuff tears monitored by MRI. Thirty-eight shoulders diagnosed as having rotator cuff tears by MRI were treated conservatively. More than six months after diagnosis, we performed MRI again. The oblique coronal view showed that 31.6% of the tears increased in size by more than 5mm/year. Shoulders that had 1～3-cm tears initially showed a significant increase in the mediolateral dimension compared with ～1-cm tears (P<0.05) and>3-cm tears (P<0.01). Tears that measured 1～3-cm initially showed a significant increase in the anteroposterior dimension compared with>3-cm tears (P<0.05). Furthermore, localized tears in the posterior part of the superior facet showed a significant increase in the mediolateral dimension compared with tears localized in the anterior part of the superior facet (P<0.05) and widespread tears in the superior facet and middle facet (P<0.05). Tears localized in the posterior part of the superior facet showed a significant increase in the anteroposterior dimension compared with widespread tears located in the superior facet and middle facet (P<0.05). These results may be useful for determining the indications for conservative treatment or operative treatment.