Several patients in their 50s and 60s have had their rotator cuff tear diagnosed on MRI. How accurate is MRI for this purpose? Could it be overinterpreted?
—Jorge Guzman Ortiz, MD, Jayuya, P.R.
The sensitivity and specificity of MRI in detecting even partial tears has been estimated at 88%-100%. However, intermediate signal present within the tendon because of magic angle phenomenon, muscle and tendon fiber interdigitation, or tendinopathy related to degenerative changes or overuse injury can sometimes be interpreted as small tears. One study found that across a wide age range, the overall prevalence of asymptomatic tears of the rotator cuff was 34% (J Bone Joint Surg. 1995;77:10-15). The frequency of full-thickness and partial-thickness tears increased significantly with age, with asymptomatic tears identified in 54% of individuals who were older than 60.
—Joseph J. Ruane, DO, medical director, McConnell Spine, Sport and Joint Center, and assistant clinical professor of medicine, The Ohio State University College of Medicine, Columbus (99-16)