A rotator cuff tear is a leading cause of shoulder pain and disability in adults. When the rotator cuff is torn, it can significantly weaken the shoulder, making even simple daily activities, such as combing your hair, reaching for objects, or getting dressed, both painful and challenging.
The shoulder is a ball and socket joint comprised of the humerus (upper arm bone), scapula (shoulder blade), and clavicle (collarbone). The head of the humerus fits into a shallow socket in the scapula, stabilized by the rotator cuff, a group of four muscles and their tendons that form a protective covering. This structure attaches the humerus to the shoulder blade, allowing arm lifting and rotation. Between the rotator cuff and the acromion, a bursa acts as a cushion, enabling smooth tendon gliding. Injury to the rotator cuff may cause the bursa to be inflamed, leading to discomfort and restricted movement.
A rotator cuff tear occurs when one or more tendons of the shoulder partially or fully detach from the humerus, often affecting the supraspinatus tendon. Tears frequently begin with fraying and may worsen over time, potentially resulting from lifting heavy objects or repetitive strain. There are different types of tears for example partial tears, full thickness incomplete tear, and full thickness complete tear. With partial tear, the tendon remains attached to the bone but is thinned, as the tear does not extend through its entire thickness. For full thickness incomplete tear, part of the tendon detaches, leaving a segment still connected to the bone. In full thickness complete tear, the tendon completely detaches from the bone, creating a gap or hole in the tendon.
Rotator cuff tears are caused by injury or gradual wear. A sudden injury, such as falling on an outstretched arm or lifting a heavy object, can lead to an immediate tear, often alongside injuries like dislocated shoulders or fractures. Some tears occur gradually, caused by tendon degeneration with age. This may be due to repetitive stress from activities like weightlifting. Aging reduces blood supply to the tendons, impairing their ability to repair minor damage, leading to eventual tears.
The symptoms of a rotator cuff tear depend on whether the injury is acute or degenerative. Acute tears, such as those from a fall, cause sudden, intense pain, a snapping sensation, and immediate upper arm weakness. Degenerative tears develop gradually, with initial mild discomfort that progresses to pain at rest or during sleep. Some tears, however, may not cause pain but still lead to arm weakness.