= TENNIS ELBOW = TENDINITIS (epicondylitis is a misnomer)

= chronic overuse syndrome involving origin of extensor carpi radialis brevis tendon

Age: 35–50 years

Cause: tennis, throwing sports, swimming, carpentry, plumbing (repetitive forearm pronation + supination with wrist extension)

• pain + tenderness in region of lateral epicondyle radiating into forearm

Histo: tendon microtears followed by formation of angiofibrotic hyperplasia (= noninflammatory reactive tissue)

MR (oblique coronal images):

• focally hyperintense signal compared with muscle + less intense than fluid on all sequences

Rx:

1. conservative management: avoidance of painful activity, application of ice, NSAID
2. splints, steroid injection
3. excision of abnormal tissue + decortication of epicondyle + reattachment of tendon

DDx of painful elbow: injury to radial collateral ligament / extensor carpi radialis longus tendon, cartilage defect