Prevalence: Rotator cuff tears are very common in the elderly population.
- Age – The condition is uncommon in patients younger than 40 years (less than 4% incidence), but it is estimated to affect between 20% and 30% of individuals older than 60 years. As many as 50% of patients older than 80 years have full-thickness rotator cuff tears. While young patients are much less likely to experience rotator cuff tears, those who do are usually involved in throwing / overhead sports or experience a major traumatic event affecting their shoulder (such as a dislocation, falling off a horse, motor vehicle accident, or power lifting injury).
- Sex / gender – Men are more commonly affected than women.
Pathophysiology: While acute tears are usually the result of traumatic injury, the pathophysiology of chronic or acute-on-chronic tears is thought to involve intrinsic degeneration of the supraspinatus, infraspinatus, teres minor, or subscapularis (SITS) muscles over time, due to a combination of impingement and imbalanced loading. There is likely a genetic component that has not been elicited that also contributes to rotator cuff tearing.
Grade / classification system: Goutallier Classification – described on CT or MRI is a way to evaluate the extent of fibrofatty infiltration of a torn rotator cuff muscle-tendon unit.
Stage 0: Normal muscle, no fat
Stage 1: Few fatty streaks in muscle
Stage 2: Less fat than muscle within the muscle
Stage 3: Same amount of fat and muscle within the muscle
Stage 4: More fat than muscle within the muscle