Radial head fracture. A potentially complex injury.

A prospective study was undertaken on 50 acute, consecutive fractures of the radial head. Clinical examination and stress testing were performed on each patient. A valgus stress radiograph, in conjunction with clinical stress testing, was used to assess competence of the medial elbow ligaments. Axial stability of the radius was determined by the axial stress test. Eleven patients (22%) sustained a comminuted radial head fracture; all had instability either to valgus or axial stress. Seventeen patients (34%) had a displaced vertical shear type fracture or an impacted fracture of the radial neck. All sustained some injury to the medial collateral ligament, with variable degrees of valgus elbow instability. Twenty-two (44%) of the fractures were minimally or nondisplaced. All 22 were stable. Radial head fracture morphology can be used to assess the likelihood of associated soft-tissue injury.