Rotator cuff injury

The rotator cuff is a group of four muscles (supraspinatus, infraspinatus, subscapularis, and teres minor) and their tendons that together form a cuff around the shoulder joint. Their function is to hold the head of the humerus (upper arm bone) securely within the shallow glenoid socket of the scapula, while allowing the wide range of motion the shoulder requires.

A rotator cuff injury refers to any damage within this musculotendinous complex — a spectrum ranging from tendinitis (inflammation of the tendon) and subacromial bursitis, through partial-thickness tears, to full-thickness (complete) ruptures.

**Causes:** - *Degenerative:* the most common cause — gradual wear and tear from repetitive overhead movements (painting, carpentry, swimming, throwing sports) over months or years. Risk increases markedly after age 60 - *Traumatic:* a single acute event such as a fall on an outstretched arm, a direct blow to the shoulder, or a heavy lifting injury - *Impingement:* the supraspinatus tendon is particularly vulnerable to impingement against the acromion, contributing to both inflammation and tearing

**Risk factors:** age over 60, occupations requiring repetitive overhead work, racquet and throwing sports, family history.

**Symptoms:** - Deep, dull ache in the shoulder, often felt in the outer arm - Pain worsening with use — specifically lifting, reaching overhead, or reaching behind the back - Pain at night, often disturbing sleep (especially lying on the affected shoulder) - Weakness when lifting the arm, rotating the shoulder, or carrying objects - Reduced range of motion — difficulty combing hair or reaching behind the back - Clicking, catching, or popping sensation with movement

**Untreated rotator cuff injuries** carry a risk of progressive enlargement of the tear, worsening weakness, and the development of rotator cuff arthropathy (degenerative glenohumeral joint disease). Prolonged immobilisation risks adhesive capsulitis (frozen shoulder).

**Treatment:** - *First-line:* relative rest, activity modification, NSAIDs, and a structured physiotherapy programme targeting rotator cuff and periscapular muscle strength and flexibility - *Injections:* subacromial corticosteroid injection for acute bursitis and impingement; prolotherapy and platelet-rich plasma (PRP) for chronic tendinopathy; ozone therapy - *Surgical:* arthroscopic or open repair for full-thickness tears, particularly in younger, active patients; debridement for partial tears that fail conservative management - *Adjunct interventions:* pulsed radiofrequency, low-level laser therapy, and acupuncture as complements to physiotherapy