Radius and Ulnar Shaft Fractures

The hand plays a critical role in our interaction with the environment and allows us to interact with objects in space physically. The forearm provides the bony structure and muscular origins that allow the hand to operate in many orientations. The 2 bones of the forearm function to allow flexion and extension at the elbow as well as at the wrist via diarthrodial joints.

The radius and ulna exist in a delicate anatomical balance that allows for pronation and supination of the hand in a 180-degree arc of motion. The anatomical bow of the radius allows for rotation around a fixed ulna, and its structure is critical for this motion. Any disruption in the anatomy of the forearm can lead to a significant loss of the normal range of motion that allows for motions as complex as a golf swing or as simple as turning the page in a book. The proximal ulna articulates with both the distal humerus, forming the ulnohumeral joint, and the proximal radius, forming the proximal radioulnar joint.

Multiple ligamentous structures stabilize the proximal radioulnar joint, and these ligaments are dynamic throughout forearm motion. The stability of this joint is critical to the overall stability of the elbow. Similarly, the distal radioulnar joint integrity is equally crucial to the stability of the wrist. An interosseous membrane joins the radius and ulnar diaphysis and is susceptible to injury during forearm fractures. This topic focuses on simultaneous diaphysial fractures of the radius and ulna in adults, often referred to as ‘both bone’ forearm fractures. Both bone fractures are traditionally seen in the pediatric population but are common in the skeletally mature individual.