Rotator Cuff Tear
Partial or full-thickness disruption of one or more rotator cuff tendons, most commonly supraspinatus, driven by age-related degeneration and mechanical factors.
Overview
The rotator cuff (supraspinatus, infraspinatus, teres minor, subscapularis) centres the humeral head in the glenoid and powers rotation. Tears are common and may be degenerative, traumatic, or, most frequently, acute-on-chronic. The natural history is progressive, with many asymptomatic tears becoming symptomatic over time and increasing in size.
Epidemiology
Prevalence rises sharply with age: around 10 percent in those under 60 and more than 50 percent in those over 80. Most are asymptomatic. Dominant arm use, overhead occupation, smoking, and diabetes increase risk.
Symptoms
Lateral shoulder pain, nocturnal pain particularly when lying on the affected side, and painful arc on abduction are typical. Weakness on external rotation (infraspinatus) or in empty-can testing (supraspinatus) indicates full-thickness tear. Lift-off and belly-press tests assess subscapularis.