Shoulder
Rotator Cuff Tear
회전근개 파열
Tear of the rotator cuff tendons causing pain, weakness, and difficulty raising the arm
- How common
- Very Common (50+)
- Typical age
- Ages 40–70
What is it?
The supraspinatus is most commonly torn (95%). Degenerative tears occur in the critical zone (poor blood supply, 1 cm from insertion). Acute tears from traumatic falls.
Commonly affected: Supraspinatus 80% (most common), infraspinatus 40% concurrent
How it develops
- Critical Zone HypovasculartySupraspinatus critical zone (1 cm from insertion) is hypovascular — vulnerable to degeneration
- Tendon DegenerationRepetitive impingement and overuse cause tendon degeneration and partial-to-full tears
- Loss of Humeral Head DepressionRC tear causes superior migration of humeral head — impingement worsens
- Weakness & PainTear causes weakness in abduction (supraspinatus) and external rotation (infraspinatus)
Symptoms
- Weak AbductionPain and weakness lifting arm to the side (abduction) — supraspinatus function
- Night PainSevere night pain, especially lying on affected shoulder — hallmark of RC tear
- Painful Arc (60–120°)Pain arc 60–120° of abduction (supraspinatus in contact with acromion)
- Weak External RotationWeakness rotating arm outward — infraspinatus/teres minor involvement
- Muscle Atrophy (Chronic)Supra/infraspinous fossa atrophy in chronic full-thickness tears
How it is examined
- Positive Drop Arm TestFully abduct arm passively — cannot lower slowly; drops suddenly = full-thickness tear
- Jobe/Empty Can TestThumb-down (empty can) arm at 90° abduction — resistance reveals supraspinatus weakness
- External Rotation Lag SignResistance to external rotation at side reveals infraspinatus tear
Imaging
X-ray shows superior humeral head migration (AHD <7mm suggests massive tear), acromial morphology (type III = hook shaped = risk factor).
- Superior humeral head migration
- Reduced acromiohumeral distance (<7mm)
- Acromial spur or hooked acromion (type III)
MRI gold standard — classifies tear (partial vs full-thickness), measures size, assesses retraction and fatty atrophy (Goutallier grading).
- Supraspinatus tendon discontinuity
- T2 hyperintense signal at tear site
- Degree of tendon retraction
- Fatty infiltration (Goutallier grade — chronic)
Non-surgical care
- Physical Therapy + RC StrengtheningRestore ROM, strengthen all RC muscles + periscapular stabilizers
- NSAIDs + Subacromial Steroid InjectionSubacromial corticosteroid injection for pain relief (limit to 3 injections)
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
Full-thickness tear with acute trauma, failed 3–6 months PT, young/active patient
Procedures that may be discussed
- Arthroscopic rotator cuff repair (gold standard)
- Double-row repair for small/medium tears
- Massive irreparable tear: superior capsule reconstruction or reverse TSA
Outlook
Small/medium tears: 80–90% excellent outcomes. Massive tears: 20–30% retear rate; reverse TSA may be needed.