The rotator cuff is the collective term for the four muscle-tendon units surrounding the glenohumeral joint, each contributing to both rotation and joint compression. The supraspinatus initiates and assists abduction, the infraspinatus and teres minor externally rotate, and the subscapularis internally rotates. Together they compress the humeral head into the glenoid and counterbalance the deltoid's superiorly directed force, keeping the shoulder stable during overhead activities.
Dynamic stabilisation of the glenohumeral joint; shoulder rotation; prevention of superior humeral head migration
Rotator cuff tears are among the most prevalent musculoskeletal diagnoses in adults over 50, with full thickness tears present in approximately 30 percent of people over 60 years old based on cadaveric and MRI studies. Symptoms correlate poorly with imaging findings as many large tears are asymptomatic. Treatment decisions are based on symptom duration, tear size, patient age, activity demands, and muscle quality on MRI. Partial thickness tears and small full thickness tears are managed with physiotherapy, with surgery considered for failure of conservative care.
The most common rotator cuff tear, occurring at the critical zone near the supraspinatus insertion, producing anterolateral shoulder pain and weakness of abduction with a positive drop arm test.
Combined tear of two or more rotator cuff tendons producing significant shoulder weakness, superior humeral migration, and eventually rotator cuff arthropathy, requiring complex surgical reconstruction or reverse shoulder arthroplasty.
