How common are rotator cuff tears?
The incidence of partial rotator cuff tears increases with age and can result from trauma or tendon degeneration from chronic impingement:
- Age 40 years: 33%
- Age 50 years: 55%
- Age 60 years: 65%
- Age 70 years: 80%
Most are relatively asymptomatic and 30% to 50% are bilateral. Weakness may be demonstrated on supraspinatus testing (50% sensitivity, 60% specificity). Full thickness tears are less common (25% of individuals aged >60 years) and should be suspected in patients with shoulder muscle atrophy, those who “hike” the shoulder when asked to lift the arm, and in patients with a positive drop arm test (30% sensitivity, 90% specificity).