Radial Head Fracture

9.18 Radial Head Fracture

Presentation
A patient has fallen on an outstretched hand and has a normal non-painful shoulder, wrist, and hand, but pain in the elbow joint . The joint may be intact, with full range of flexion, but there is pain or decreased range of motion on extension, supination and pronation. Tenderness is greatest over the radial head and lateral condyle. X rays may show a fracture or dislocation of the head of the radius. In all views, a line down the center of the radius should point to the capitellum of the lateral condyle. Often, however, no fracture is visible, and the only x ray signs are of the elbow effusion or hemarthrosis pushing the posterior fat pad out of the olecranon fossa and the anterior fat pad out of its normal position on the lateral view.
What to do:



Obtain a detailed history of the mechanism of injury, and a physical examination, looking for the features described above, and x rays of the elbow, looking for visible fat pads as well as fracture lines.



If there is any question of a radial head fracture, immobilize the elbow (preventing pronation and supination of the hand) with a gutter splint extending from proximal humerus to hand, or sugar tong splints, or simply a sling, for the next week.



Explain to the patient the possibility of a fracture, despit negative x rays, and arrange for followup, with re- evaluation and repeat films in 1-2 weeks.
What not to do:



Do not jump to the diagnosis of "tennis elbow or "sprained elbow" simply on the basis of a negative x ray.
Discussion
Small, non-displaced fractures of the radial head may show up on x rays weeks later or never at all. Because pronation and supination of the hand are achieved by rotating the radial head upon the capitellum of the humerus, very small imperfections in healing of the radial head may produce enormous impairment of hand function, which may be only partly improved by surgical excision of the radial head. Immobilization at the first question of a radial head fracture may help preserve essential pronation and supination. "Tennis elbow" is a tenosynovitis of the common insertion of the wrist extensors upon the lateral condyle, and results in pain on wrist extension rather than on pronation and supination.