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Rotator CuffEdit

The rotator cuff refers to a group of four tendinous tendons that surround the shoulder joint, stabilizing the glenohumeral joint and enabling a wide range of arm movements. This musculotendinous cuff maintains the humeral head centered in the glenoid during lifting, throwing, and overhead activities. Because the cuff bears repetitive stress and supports a joint with substantial mobility, it is a common source of shoulder pain and dysfunction, particularly with aging, overuse, or trauma.

Anatomy

  • Supraspinatus: This muscle sits at the top of the shoulder blade and its tendon traverses the subacromial space to attach to the greater tubercle of the humerus. It plays a key role in initiating arm abduction.
  • Infraspinatus: Located below the spine of the scapula, its tendon inserts on the posterior aspect of the humeral head and contributes to external rotation and stabilization.
  • Teres minor: A small muscle along the lateral border of the scapula, its tendon also inserts on the humeral head and assists with external rotation and stabilization.
  • Subscapularis: This large anterior muscle originates on the subscapular fossa and inserts on the lesser tubercle of the humerus, providing internal rotation and anterior stability.

Together, the four tendons fuse to form the rotator cuff and envelop the humeral head, helping to center it within the glenoid during arm movement. The cuff works in concert with the deltoid muscle and other shoulder stabilizers, and its tendons pass close to the acromion, where the space between the acromion and the humeral head is the Subacromial space.

Function

The rotator cuff stabilizes the shoulder during activity and allows multiple planes of motion: - Abduction (especially initiation by the supraspinatus) - External rotation (infraspinatus and teres minor) - Internal rotation (subscapularis) The cuff also helps preserve joint congruity when the arm is raised or rotated, reducing shear forces on the glenohumeral joint and distributing load through the joint during athletic or occupational tasks.

Pathology

Rotator cuff problems span a spectrum from tendinopathy to full-thickness tears. Common issues include: - Tendinopathy and partial-thickness tears: Degenerative changes or repetitive microtrauma can lead to pain and weakness, often presenting with overhead activity intolerance. - Full-thickness tears: Tears that extend through the entire thickness of a tendon, which can result from acute trauma or progressive degeneration, leading to marked weakness and limited function. - Impingement: Reduced subacromial space or acromial morphology can compress the cuff tendons, causing pain with overhead movements. - Calcific tendinopathy: Deposition of calcium within the tendons can provoke acute or chronic shoulder pain. - Associated conditions: Biceps tendon pathology and other glenohumeral disorders may accompany rotator cuff disease.

Risk factors include aging, repetitive overhead activity, traumatic injury, and certain anatomical features such as acromial shape or muscle-tendon quality. Management decisions often depend on tear size, tendon quality, patient age, activity goals, and overall shoulder health.

Symptoms and diagnosis

Patients may report pain with overhead activities, night pain, and a sense of weakness or limited function. Specific signs can include difficulty initiating abduction or external rotation and a reduction in shoulder strength. Diagnostic workup typically includes: - History and physical examination, with provocative tests for cuff integrity - Imaging: plain radiographs to assess bone and acromial morphology; ultrasound or magnetic resonance imaging (MRI) to evaluate tendon integrity and surrounding structures - Differential diagnosis may consider adhesive capsulitis, glenohumeral arthritis, or cervical spine issues if symptoms are diffuse

Treatment

Management is individualized and often starts with nonoperative approaches, reserving surgery for persistent or large tears, or when function is essential for the patient’s activities: - Nonoperative care: Activity modification, targeted physical therapy to improve scapular control and rotator cuff strength, range-of-motion exercises, and pain control with nonsteroidal anti-inflammatory drugs (NSAIDs) or other analgesics. Corticosteroid injections into the subacromial space may provide short-term relief but have variable long-term effects. - Rehabilitation: A structured program emphasizes gradual loading, tendon healing, and neuromuscular training to restore function and reduce re-tear risk. - Surgical options: When nonoperative treatment fails or when tears are full-thickness and functionally limiting, procedures such as arthroscopic rotator cuff repair may be considered. Techniques include single-row or double-row repairs, tendon debridement for smaller degenerative lesions, and, in select cases, biceps tendon management. Postoperative rehabilitation is critical to optimize outcomes. - Alternative approaches: In some cases, tissue augmentation or tendon transfers may be discussed for irreparable tears, and some older patients with low functional demands may opt for nonoperative strategies rather than repair.

Prognosis and prevention

Outcomes depend on tear size and chronicity, tissue quality, patient age, and adherence to rehabilitation. Re-tear rates after repair vary with technique and tear characteristics, but many patients regain meaningful function and pain relief with appropriate treatment. Prevention focuses on maintaining scapular stability, balanced shoulder strength, proper biomechanics during activity, and conditioning to reduce overuse injuries.

See also