A distal radius fracture, commonly known as a wrist fracture, is defined by the involvement of the metaphysis of the distal radius. The fracture may or may not involve the radiocarpal joint, distal radioulnar joint, and/or the distal ulna. This injury is commonly associated with high-energy mechanisms in younger patients and lower energy mechanisms or falls in older patients. The fracture results in acute wrist pain and swelling, and if left untreated, it can result in significant morbidity. Treatment can involve both non-operative and operative management and ultimately depends on multiple factors.
The mechanism of injury in a distal radius fracture is an axial force across the wrist with the pattern of injury determined by bone density, the position of the wrist, and the magnitude and direction of the force. Most distal radius fractures result from falls with the wrist extended and pronated. This places a dorsal bending moment across the distal radius. This type of injury is often referred to as a "fall onto an outstretched hand" or FOOSH. The relatively weaker, thinner dorsal bone collapses under compression; whereas, the stronger volar bone fails under tension resulting in a characteristic “triangle” of bone comminution with the apex volar and greater comminution dorsal. Cancellous impaction of the metaphysis compromises dorsal stability, and shearing forces impact the injury pattern which often involves the articular surface. High-energy injuries may result in significantly displaced or highly comminuted unstable fractures to the distal radius.
Common mechanisms in younger individuals
Common mechanisms in elderly individuals
A distal radius fracture is the most common fracture of the upper extremity. These fractures happen in all patient populations and are the most common orthopedic injury with a bimodal distribution. More than 450,000 fractures occur annually in the United States, and that number continues to rise. Fractures of the distal radius represent approximately one-sixth of all fractures treated in emergency departments. Younger patients tend to be involved in higher energy trauma mechanisms, whereas older patients tend to be involved with lower energy falls. The incidence in the elderly population correlates with osteopenia and rises in incidence with increasing age which corresponds to the increased incidence of hip fractures.
Risk factors in the elderly
Patients will typically present with variable wrist deformity and displacement of the hand in relation to the wrist. The wrist is typically swollen with ecchymosis, tenderness, and painful range of motion. The mechanism of injury should be investigated to assist in assessing the energy and level of destruction. It is important to establish the patient’s functional status before the injury as well as occupational demands as these may aid in determining treatment direction. Document co-existing medical conditions that may affect healing such as osteoporosis, diabetes, and/or tobacco use.
The physical examination should include careful attention to the following:
Associated injuries include:
Imaging confirms fracture severity, determines stability, and guides the treatment approach. Plain radiographs should be obtained before and after reduction, if necessary. The standard radiographs include posteroanterior and lateral views of the wrist, as well as oblique views for further fracture definition. Oblique views are useful to help evaluate articular involvement, particularly the lunate fossa fragment. Contralateral wrist views may evaluate the patient’s normal ulnar variance and scapholunate angle. Computed tomography scan may demonstrate the extent of intraarticular involvement. It is important to know normal radiographic measurements of the distal radius because it is useful in identifying distal radius fractures. These measurements are also useful in determining treatment.
Important normal radiographic relationships include:
Distal radius fractures may be treated non-surgically or surgically. Non-surgical treatment necessitates acceptable fracture displacement, angulation, and shortening. Should these criteria not be met, surgical treatment is recommended.
Acceptable criteria for distal radius fractures include:
Displaced fractures must undergo a closed reduction in an attempt to achieve an anatomic or acceptable reduction. Adequate anesthesia or analgesia, such as conscious sedation or hematoma block, are necessary for closed reduction. Following the closed reduction, the arm should be immobilized in a long-arm, sugar-tong splint acutely, as opposed to a cast. A long-arm, sugar-tong splint prevents pronation, supination, and elbow flexion, thereby eliminating the brachioradialis as a deforming force. The splint will allow for swelling as opposed to a cast. Post-reduction radiographs must be obtained to evaluate the quality of the reduction. If the fracture reduction meets the acceptable criteria, the patient may remain in the splint and follow up with an orthopedic surgeon where weekly radiographs will be obtained for the first 2 weeks. If the reduction is not maintained and is no longer acceptable, surgical intervention should be recommended. If the reduction is maintained, the splint may be converted to a cast and immobilized for a total of 6 weeks.
Non-displaced fractures are treated without surgery in a long-arm splint acutely and transitioned to a short-arm cast in the office for a total of 6 weeks with serial radiographs to monitor for fracture displacement and healing.
For fractures that do not meet acceptable alignment, surgical intervention is recommended. The goal of surgical treatment is to achieve acceptable alignment and stable fixation for early motion. There are various methods of fixation including pins, external fixators, dorsal plates, and a volar plate. Percutaneous pinning is useful in maintaining sagittal length and alignment in extra-articular fractures with a stable volar cortex. It is unacceptable when the volar cortex is comminuted, and therefore unstable, as there is not enough bony fixation to maintain reduction. Good outcomes have been reported up to 90% of the time if used appropriately. External fixation is often used in conjunction with percutaneous pin or plate fixation as it does not reliably restore the volar tilt on its own. This technique relies on ligamentotaxis to maintain fracture reduction. It is essential to limit the duration of external fixation to a maximum of 8 weeks and to perform aggressive hand therapy to maintain range of motion of the hand. Good outcomes have been reported up to 90% of the time if used appropriately. Open-reduction internal fixation with volar plating is much more common than dorsal plating. Volar plating is associated with irritation of both flexor and extensor tendons and flexor pollicus longus tendon rupture may be seen. Volar plating offers support to the subchondral bone to help maintain fracture reduction. Dorsal plating is associated with extensor tendon irritation and rupture. It is typically indicated for displaced intra-articular fractures with dorsal comminution.
Radiographs confirm diagnosis; however, the following must be considered.
Multiple Classification Systems of Distal Radius Fractures
Based on the pattern of intraarticular involvement
Based on the mechanism of injury
Common Eponyms for Distal Radius Fractures
Overall good to excellent results can be expected in over 80% of patients regarding a range of motion, strength, and outcomes scoring with open-reduction internal fixation and volar plating. Studies comparing volar fixation to other forms of fixation have revealed similar if not superior results. Results appear to be superior in the early recovery period with the outcome yielding equivalent results among all fixation groups. Some studies suggest better maintenance with volar plating in overall reduction compared to other forms of fixation.
Median Nerve Neuropathy (Carpal Tunnel Syndrome)
Extensor Pollicus Longus Tendon Rupture
Complex Regional Pain Syndrome
Postoperative care for open-reduction internal fixation with volar plating includes immediate volar splinting following surgery. The patient is instructed to perform active range of motion exercises for the digits and elevate their wrist above heart level to prevent stiffness and aid in edema control. The splint is removed 1 to 2 weeks after surgery for a wound check. A removable splint should be fabricated by a hand therapist to help with edema and worn at all times to protect fracture fixation. The patient should remain non-weight bearing of the upper extremity but may begin active range of motion exercises of the wrist after the first post-operative visit. At 4 to 6 weeks putty and grip exercises may be added. At 6 to 8 weeks the splint is discontinued, and progressive strengthening exercises are advanced. The patient will typically be discharged to activities as tolerated at the 10 to 12-week mark.