Wrist Fracture in Emergency Medicine Clinical Presentation

Updated: Dec 22, 2017
  • Author: Bryan C Hoynak, MD, FACEP, FAAEM; Chief Editor: Trevor John Mills, MD, MPH  more...
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Presentation

Physical

Physical examination should begin with inspection of the injured extremity using the uninjured extremity as a comparison. The site of injury may be identified by ecchymosis or swelling. Fractures of the distal radius may have characteristic deformities. Look for any evidence of a break in the skin indicating an open fracture. Palpation with localization of the point of maximal tenderness further defines the injury.

With scaphoid fractures, the point of maximal tenderness lies in the anatomic snuffbox, which lies between the tendons of the extensor pollicis brevis and abductor pollicis longus. Radial deviation of the wrist or axial loading of the first metacarpal may increase pain.

The lunate can be localized just distal to the Lister tubercle, which is palpable on the dorsal radius. Axial loading of the third metacarpal may increase pain with a lunate injury. In addition, lunate fractures may be associated with point tenderness over the lunate fossa (located distal to the radius at the base of the long finger metacarpal).

The classic finding in a Colles fracture is the so-called dinner fork deformity, which is produced by dorsal displacement of the distal fracture fragments. A Smith fracture may show an obvious volar displacement of the wrist relative to the forearm, known as a garden spade deformity.

Examine the remainder of the injured extremity for tenderness or other signs of injury to exclude an associated injury to the elbow, upper arm, or shoulder. Particularly with injuries to the lunate, capitate, and pisiform, which represent high-energy mechanisms, maintain a high suspicion for concomitant injury to other structures of the wrist. A practical piece of advice is to examine last the region identified by the patient as the most painful; this prevents additional pain from the physical examination from masking more subtle injuries to other structures.

Next, assess the neurovascular integrity of the injured extremity. Evaluate pulses in the brachial and radial arteries. Look for any evidence of impaired circulation such as cyanosis or pallor. Injuries to the ulnar aspect of the hand, particularly those involving the pisiform, hamate, and triquetrum, may place the deep branch of the ulnar artery at risk as it travels beneath the hook of the hamate. The radial artery can be jeopardized with any significant displacement of the distal radius.

The hand is innervated by 3 nerves, the radial, ulnar, and median. Assess their integrity in all injuries. The deep branch of the ulnar nerve, which supplies most of the intrinsic muscles of the hand, runs with the ulnar artery beneath the hook of the hamate and is vulnerable with injuries to the pisiform, hamate, and triquetrum. Injuries at this point spare the sensory function of the ulnar nerve, which branches more proximally. The median nerve is particularly vulnerable with injuries to the lunate and the distal radius. It may be compromised by swelling, resulting in an acute carpal tunnel syndrome, or it may be injured directly. The sensory branch of the radial nerve may be compromised with a dorsally displaced Barton fracture.

Next:

Complications

The anatomy of the scaphoid bone makes it vulnerable to secondary injury. It is supplied by a single blood vessel that penetrates the cortex near the waist of the scaphoid. Scaphoid fractures are prone to delayed healing and avascular necrosis. The more proximal the fracture, the more common these complications. Missed diagnosis and lack of appropriate immobilization increase this risk. Missed diagnosis or nonunion predisposes an individual to development of potentially debilitating radiocarpal arthritis.

Keinböck disease is osteonecrosis and subsequent collapse of the proximal portion of the lunate resulting in pain, loss of function, and carpal bone instability. The exact mechanism for development of this condition is disputed, with theories ranging from repetitive microtrauma to avascular necrosis from a single injury. As the lunate receives its blood supply from a single distal blood vessel in 20% of individuals, these patients may be predisposed to avascular necrosis and nonunions. Younger patients, typically those younger than 16 years, tend to have better functional outcomes from lunate injuries than older patients.

Complications from a capitate fracture include nonunion and avascular necrosis, as, like the scaphoid, it is dependent on a single blood vessel, which enters from its distal aspect. Posttraumatic arthritis is a frequent complication. Fibrosis of surrounding tissues after injury may result in carpal tunnel syndrome.

Fractures through the base of the hook of the hamate are frequently displaced by the forces of the hook's multiple ligamentous attachment. Nonunion is a frequent complication and may necessitate surgical excision of the hook to relieve pain from grasping activities.

Acutely, a Colles fracture has several potential complications. These include compression or contusion of the median and/or ulnar nerves. An acute carpal tunnel syndrome may result from swelling. The flexor tendons may be injured by the bony fragments. Excessive swelling can result in compartment syndromes. Comminuted or severely displaced fractures may be unstable, resulting in a loss of reduction and requiring repeated attempts or surgical intervention.

Long term, the wrist may have radial shortening and angulation deformity, limiting range of motion. Some individuals experience chronic pain, particularly with supination. Adhesions may limit mobility of the flexor tendons. As with all fractures, malunions or nonunions may complicate healing. With comminuted intra-articular fractures, more than two thirds may be complicated by the late development of arthritis.

Reflex sympathetic dystrophy complicates some 3% of distal radius fractures. This controversial diagnosis is a syndrome of paresthesias, pain, stiffness, and changes in skin temperature and color.

Smith (reverse Colles) fracture may result in complications similar to those of Colles fracture.

Radiocarpal fracture-dislocation may cause entrapment of tendons or of the ulnar nerve and/or artery. [13]

Hutchinson fracture may result in scapholunate dislocation, osteoarthritis, or ligament damage.

Ulnar styloid fracture often results in nonunion.

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