The rotator cuff is a complex of four muscles and their tendons that surround the shoulder joint. This group stabilizes the humerus, or upper arm bone, within the shoulder socket and facilitates smooth arm movement, particularly rotation and elevation. A rotator cuff tear occurs when one or more of these tendons are pulled away from the bone, either acutely from injury or gradually from degeneration. While surgery is often recommended to restore the tendon’s attachment, many individuals delay repair or pursue non-operative management. This decision raises questions about the long-term consequences of leaving the structural damage unrepaired.
Progression of the Tear
When a full-thickness rotator cuff tear is left unrepaired, the structural defect typically begins to enlarge. This progression is caused by the ongoing mechanical forces and tension exerted by the remaining muscle tissue. Studies show that a significant percentage of full-thickness tears will progress in size within a few years of diagnosis, making the initial injury a dynamic problem.
The edges of the torn tendon are pulled away from the humerus attachment site by the unopposed tension of the attached muscle fibers, a process known as tendon retraction. This retraction widens the gap between the tendon and the bone, increasing the difficulty of surgical reattachment later on. The degree of retraction is a major factor in determining the feasibility of a successful future repair.
A concerning biological change that occurs within the muscle is the progression of muscle atrophy and fatty infiltration. When the tendon is torn and retracted, the associated muscle loses its normal tension and function. This causes the contractile muscle tissue to shrink and be replaced by fat, a process that is often irreversible.
High-grade fatty infiltration severely compromises the muscle’s quality and its ability to contract effectively, even if the tendon is repaired. This degenerative process is a strong predictor of poor surgical outcomes and is a primary reason a tear may eventually be classified as “irreparable.” Fatty changes can occur relatively quickly, sometimes within a year or two of tear enlargement. This highlights the narrow window for intervention before the tissue quality is permanently degraded.
Functional Decline and Weakness
The structural degradation within the shoulder complex translates directly into a progressive decline in functional ability. A pronounced consequence is the loss of strength, particularly when attempting to lift the arm overhead or rotate it outward. This weakness stems from the impaired force transmission of the compromised rotator cuff muscles, making everyday actions like reaching a high shelf or performing simple dressing tasks challenging.
Pain is a defining characteristic, often evolving from acute discomfort to a chronic, dull ache. This chronic pain is frequently worse at night, particularly when lying on the affected side, and can significantly disrupt sleep patterns. The rotator cuff’s inability to stabilize the shoulder causes other muscles to compensate, which leads to fatigue and secondary pain in the neck and shoulder blade region.
The restriction in movement is typically a loss of active range of motion, meaning the patient cannot lift or move the arm themselves. This differs from passive range of motion, where the arm can still be moved by a doctor. In severe, long-standing cases, the weakness can become so profound that the individual develops “pseudoparalysis,” an inability to actively elevate the arm above 90 degrees.
This functional limitation forces the body to adopt altered movement patterns, leading to instability and placing stress on other joints and muscles. Chronic compensation increases the risk of secondary issues, such as adhesive capsulitis, commonly known as frozen shoulder. The cumulative effect is a significant reduction in overall function and quality of life.
Long-Term Structural Consequences
The final stage of a long-unrepaired rotator cuff tear is the development of severe, degenerative joint changes, known as cuff tear arthropathy (CTA). This is a specific form of advanced shoulder arthritis. When the rotator cuff is no longer intact, it fails to hold the humeral head centered within the glenoid socket.
Without the stability provided by the cuff, the powerful deltoid muscle causes the humeral head to migrate upward (superiorly). This migration causes the head to rub abnormally against the acromion, the bony roof of the shoulder. This abnormal contact rapidly wears down the joint cartilage, resulting in bone-on-bone friction and severe osteoarthritis. This mechanical derangement causes significant pain and severely limits functional movement.
Once a tear has progressed to advanced fatty infiltration, significant retraction, and the development of CTA, it is considered truly “irreparable” by standard surgical techniques. The tendon tissue is too poor in quality and too retracted to be successfully reattached to the bone with a reasonable chance of healing. This leaves the patient with few choices other than complex salvage procedures.
The most common definitive treatment for established cuff tear arthropathy is a reverse total shoulder replacement. This procedure structurally reverses the ball-and-socket anatomy, allowing the deltoid muscle to function as the primary elevator of the arm. While effective for pain relief and restoring some function, this major reconstructive surgery represents the endpoint of the degenerative process and is a more complex intervention than an early repair.