Rotator cuff disorders

Rotator cuff disorders encompass a spectrum of conditions involving the supraspinatus, infraspinatus, teres minor, and subscapularis muscles or their tendons, including rotator cuff tendinopathies with or without calcifications, partial-thickness rotator cuff tears, and full-thickness rotator cuff tears.

Rotator cuff disorders typically arise through chronic degenerative processes or acute traumatic events. Degeneration involves progressive collagen disruption, vascular insufficiency, inflammation, and microtears, sometimes accompanied by calcifications, especially affecting the dominant arm and becoming increasingly common with age or repetitive overhead stress. Mechanical impingement between the humeral head and subacromial arch exacerbates these degenerative changes, further compromising tendon integrity. Acute rotator cuff tears, however, result from direct trauma, often occurring alone or associated with additional shoulder injuries, such as clavicle fractures or shoulder dislocations. Both degenerative and acute tears may range from partial-thickness lesions to complete tendon ruptures, significantly impairing shoulder function.

Shoulder pain accounts for approximately 4.5 million patient visits annually in the US. More than two-thirds of patients undergoing rotator cuff repair are of working age. The prevalence of rotator cuff tears increases with age; imaging studies demonstrate partial or complete rotator cuff tears in up to 54% of asymptomatic individuals aged 60 years or older.

Risk factors for rotator cuff disorders include advanced age, repetitive overhead activities, trauma, smoking, diabetes mellitus, and occupations requiring sustained shoulder elevation or heavy lifting. Individuals who frequently perform repetitive lifting or overhead motions, such as painters and carpenters, are particularly susceptible to tears. Athletes, notably tennis players and baseball pitchers, are also at increased risk due to repetitive microtrauma and overuse injuries.

Clinically, rotator cuff disorders present with a gradual onset of shoulder pain exacerbated by overhead activities, night pain, and progressive limitations in ROM and strength, which without intervention may progress to persistent pain, functional impairment, and chronic disability.