A wrist can be dislocated, and this serious orthopedic injury requires immediate medical attention. While a sprain involves stretched or torn ligaments and a fracture is a broken bone, a true wrist dislocation occurs when the bones that form the joint are forced out of their normal alignment. These are often high-energy injuries resulting from significant trauma, frequently accompanied by fractures and extensive ligament damage. Any disruption of the wrist’s complex structure can lead to long-term problems if not treated promptly.
The Complex Anatomy of a Dislocated Wrist
The wrist is not a single joint but a complex arrangement of eight small bones, known as the carpal bones, which connect the forearm bones—the radius and the ulna—to the bones of the hand. These carpal bones are organized into two rows, proximal and distal, which articulate with one another and with the forearm. This intricate structure allows for a wide range of motion, but it also makes the joint susceptible to complex injuries under high force.
A dense network of ligaments holds these carpal bones together and stabilizes their connection to the radius and ulna. A wrist dislocation is fundamentally a ligamentous injury, where these strong connective tissues tear, allowing one or more carpal bones to be pushed out of place. The resulting instability caused by torn ligaments is a major factor in the severity and complexity of the injury.
Immediate Symptoms and Recognizing the Injury
Immediate symptoms of a dislocated wrist include sudden, severe pain that worsens with any attempt to move the joint. This pain is accompanied by rapid and widespread swelling, sometimes extending into the forearm. The wrist may also display a noticeable deformity, appearing misshapen or misaligned due to the displaced bones.
A person with this injury experiences a significantly limited range of motion, often finding it impossible to move the wrist or grip objects. A dislocated bone, such as the lunate, can press against nerves within the carpal tunnel, causing numbness, tingling, or weakness in the fingers. Immediate medical evaluation is necessary, as delayed treatment can lead to chronic instability or permanent nerve issues.
Common Mechanisms of Injury and Specific Types
The most common mechanism for a wrist dislocation is high-energy trauma, often involving a fall onto an outstretched hand (FOOSH), particularly when the wrist is hyperextended. This forceful impact transmits an axial load through the wrist, causing a sequential tearing of the stabilizing ligaments. Accidents such as motor vehicle collisions or high-impact sports injuries also generate the substantial force required to displace the carpal bones. The specific direction and magnitude of the force determine the pattern of the resulting dislocation.
Wrist dislocations are classified based on which bones are displaced, with perilunate and lunate dislocations being the most frequent and clinically significant types. In a perilunate dislocation, the lunate bone remains aligned with the radius, but the rest of the carpal bones dislocate away from it, usually toward the back of the hand. A lunate dislocation is more severe; here, the lunate bone itself rotates and is displaced, often into the carpal tunnel toward the palm, while the other carpal bones remain relatively aligned with the radius. The progression from a perilunate to a lunate dislocation is recognized as a sequential pattern of ligament failure.
Medical Intervention and Path to Recovery
Diagnosing a wrist dislocation begins with X-rays to visualize the bones, though a computed tomography (CT) scan or magnetic resonance imaging (MRI) may also be used to assess associated fractures and ligament damage. The initial treatment goal is to realign the bones, which is achieved through a procedure called reduction. For less complex injuries, a closed reduction is performed, where a physician manually manipulates the bones back into place without surgery, often under sedation.
However, many wrist dislocations, especially the severe perilunate and lunate types, require open reduction and internal fixation (ORIF). This is a surgical procedure used to realign the bones and repair the torn ligaments. Following the reduction, the wrist is immobilized in a cast or splint for several weeks to allow the damaged tissues to begin healing. The recovery phase is lengthy, often requiring several months of dedicated physical therapy to restore strength, flexibility, and a functional range of motion. Full recovery can take six months to a year, and patients face a long-term risk of complications such as arthritis or chronic wrist instability.