The supraspinatus is the most commonly torn rotator cuff muscle. Its critical zone (the avascular area 1 cm from the insertion) is the site of degenerative tears in middle-aged and older adults. Its superior footprint on the greater tuberosity is the primary zone of attachment.
| Origin | Supraspinous fossa of the scapula — medial two-thirds |
|---|---|
| Insertion | Greater tuberosity of the humerus — superior facet (the first footprint) |
| Nerve Supply | Suprascapular nerve (C5, C6) |
| Blood Supply | Suprascapular artery |
| Actions | Initiates shoulder abduction — active 0-30 degrees; Co-activates with deltoid throughout full elevation; Provides superior humeral head compression |
|---|
Supraspinatus tears are classified by thickness (partial vs full), size, and retraction. The Jobe test (empty can) and drop arm sign are the primary clinical tests. MRI characterises tear morphology. Arthroscopic repair involves re-attachment of the tendon to the greater tuberosity footprint with suture anchors. Massive irreparable tears are managed by superior capsular reconstruction or tendon transfers.
Tested by Jobe's empty can test — resisted abduction at 30 degrees of forward flexion with thumb down.
Full-thickness supraspinatus tear at the critical zone producing shoulder weakness and pain, managed by arthroscopic repair for active patients or superior capsular reconstruction for massive irreparable tears.
