Elbow
Core concepts
Understand valgus extension overload, ulnar collateral ligament injury, distal biceps and triceps ruptures, medial and lateral epicondylitis, cubital tunnel syndrome, radial head fractures, elbow dislocation, and the terrible triad. In throwing athletes, link medial elbow pain to UCL insufficiency, posteromedial impingement, and osteophyte formation. Know the moving valgus stress test, milking maneuver, and the role of stress radiographs or MRI arthrogram. Distal biceps rupture presents with a hook test and weakness in supination; early repair improves outcomes. Cubital tunnel syndrome may cause intrinsic wasting and clawing, while posterior interosseous nerve palsy causes finger extension weakness without sensory loss.
Traps
Do not miss an Essex-Lopresti injury when a radial head fracture is associated with distal radioulnar joint tenderness; longitudinal forearm instability changes treatment. In pediatric elbow trauma, a medial epicondyle avulsion can be incarcerated in the joint after dislocation. Supracondylar fractures require careful neurovascular assessment, especially the anterior interosseous nerve. Lateral epicondylitis is usually degenerative tendinopathy, not acute inflammation, so repeated corticosteroid injections are discouraged. Elbow dislocation may reduce spontaneously; always assess stability and the ulnar nerve.
Worked example
A 16-year-old pitcher has medial elbow pain and a positive moving valgus stress test. Rule of thumb: in a skeletally immature thrower, first exclude medial epicondyle apophysitis and Little League elbow; do not proceed directly to UCL reconstruction. Rest, throwing mechanics, and a graduated program are initial management unless there is chronic instability or a clear tear.