A distal radius fracture, also known as wrist fracture, is a break of the part of the radius bone which is close to the wrist. Symptoms include pain, bruising, and swelling of rapid onset. The wrist may be deformed. The ulna bone may also be broken.
In younger people these fractures typically occur during sports or a motor vehicle collision. In older people the most common cause is falling on an outstretched hand. Specific types include Colles, Smith, Barton, and Hutchinson fractures. The diagnosis is generally suspected based on symptoms and confirmed with X-rays.
Treatment is with casting for six weeks or surgery. Surgery is generally indicated if the joint surface is broken and does not line up, the radius is overly short, or the joint surface of the radius is tilted more than 10% backwards. Among those who are casted repeated X-rays are recommended within three weeks to verify that a good position is maintained.
Distal radius fractures are common. They represent between 25 and 50% of broken bones. They occur most commonly in young males and older females. A year or two may be required for healing to occur.
Video Distal radius fracture
Signs and symptoms
People usually present with a history of an injury and localized pain. There is often a deformity in the wrist with associated swelling. Numbness of the hand can occur because of compression on the median nerve across the wrist (carpal tunnel syndrome). The wrist deformity often limits motion of the fingers.
Examination
Swelling, deformity, tenderness and loss of wrist motion are normal features on examination of a person with a distal radius fracture. Examination should rule out a skin wound which might suggest an open fracture. It is imperative to check for loss of sensation, loss of circulation to the hand, and more proximal injuries to the forearm, elbow and shoulder. The most common associated neurological finding is decreased sensation over the thenar eminence due to associated median nerve injury.
A classic "dinner fork" deformity may be seen in dorsally angulated fractures due to dorsal displacement of the carpus. The reverse deformity may be seen in volarly angulated fractures.
Associated injuries
Distal radius fractures are associated with injury to the carpal interosseous ligaments (predominantly the scapholunate and lunatotriquetral ligaments), as well as the triangular fibrocartilage complex (TFCC) if there is also concurrent injury to the ulnar styloid process. Styloid fractures can occur either to the very tip of the styloid or at the base. Because the TFCC attaches to the base of the ulnar styloid, displaced fractures can result in instability of the distal radio-ulnar joint. Carpal bone fractures such as those to the scaphoid have been described, whereas instability or dislocations of the wrist are seen with certain types of distal radius and ulna fractures. Injuries to the elbow, humerus and shoulder are also common after a fall on outstretched hand. Swelling and displacement can cause compression on the median nerve across the wrist, an acute carpal tunnel syndrome. Very rarely is pressure on the muscle components of the hand or forearm sufficient to create a compartment syndrome.
Maps Distal radius fracture
Mechanism of injury
The most common cause of this type of fracture is a fall on an outstretched hand (a "FOOSH" injury) from standing height. The risk of injury is increased in patients with osteoporosis and other metabolic bone diseases. In young adults, this fracture is the result of moderate to severe force such as a fall from a significant height or a motor vehicle accident (due to younger patients having stronger bone).
Position of hand at time of impact influences the fracture pattern. Cadaver experiments from the late 1800s found that if the forearm strikes the ground at an angle between 60-90°, a fracture would occurs. Further more, if the hand was ulnarly deviated (i.e. bent towards the small finger), there would be associated radial styloid fracture. Similarly, ff the hand was radially deviated (i.e. bent towards the thumb), this was associated with ulnar styloid fracture. If the hand is flexed, the fracture would be displaced volarly (i.e. towards the palm).
Diagnosis
Diagnosis may be evident clinically when the distal radius is deformed but should be confirmed by X-ray. The differential diagnosis includes scaphoid fractures and wrist dislocations, which can also co-exist with a distal radius fracture. Occasionally, fractures may not be seen on X-rays immediately after the injury. Delayed X-rays, X-ray computed tomography (CT scan), or Magnetic resonance imaging (MRI) will confirm the diagnosis.
Medical imaging
X-ray of the affected wrist is required if a fracture is suspected. Anteroposterior (AP), lateral, and oblique views can be used together to describe the fracture. X-ray of the uninjured wrist should also be taken to determine if there are any normal anatomic variations. Investigation of a potential distal radial fracture includes assessment of the angle of the joint surface on lateral X-ray (volar/dorsal tilt), the loss of length of the radius from the collapse of the fracture (radial length), and congruency of the distal radioulnar joint (DRUJ). Displacement of the articular surface is the most important factor affecting prognosis and treatment. CT scan is often performed to further investigate the articular anatomy of the fracture, especially if surgery is considered. MRI can be considered to evaluate for soft tissue injuries, including damage to the TFCC and the interosseous ligaments.
Classification
In medicine, classifications systems are devised to describe patterns of injury which will behave in predictable ways, to distinguish between conditions which have different outcomes or which need different treatments. Most wrist fracture systems have failed to accomplish any of these goals and there is no consensus about the most useful one.
At one extreme, a stable undisplaced extra-articular fracture has an excellent prognosis. On the other hand, an unstable, displaced intra-articular fracture is difficult to treat and has a poor prognosis without operative intervention.
Eponyms such as Colles', Smith's, and Barton's fractures are discouraged.
An anatomic description of the fracture is the easiest way to describe the fracture, determine treatment, and assess stability.
- Articular incongruity
- Volar or dorsal tilt
- Radial inclination
- Radial length and ulnar variance
- Comminution of the fracture (the amount of crumbling at the fracture site)
- Open (compound fracture) vs. closed injury
- Associated ulnar styloid fracture
- Associated soft tissue injuries
Treatment
Treatment options for distal radius fractures include non-operative management, external fixation, and internal fixation. Indications for each depend on a variety of factors such as patient's age, initial fracture displacement, and metaphyseal and articular alignment, with the ultimate goal to maximize strength, and function in the affected upper extremity. Surgeons use these factors combined with radiologic imaging to predict fracture instability, and functional outcome in order to help decide which approach would be most appropriate. Treatment is often directed to restore normal anatomy to avoid the possibility of malunion, which may cause decreased strength in the hand and wrist. The decision to pursue a specific type of management varies greatly by geography, physician specialty (hand surgeons vs. orthopedic surgeons), and advancements in new technology such as the volar locking plating system.
Non-operative
The majority of distal radius fractures are treated with conservative non-operative management, which involves immobilization through application of plaster or splint with or without closed reduction. The prevalence of non-operative approach to distal radius fractures is approximately 70%. Non-operative management is indicated for fractures that are undisplaced, or for displaced fractures that are stable following reduction. There are variations in immobilization techniques involving the type of cast, position of immobilization, and the length of time required in the cast.
The length of time in the cast varies with different ages. Children heal more rapidly, but may ignore activity restrictions. Three weeks in a cast and 6 weeks off sports may be appropriate for certain fractures. In adults, the risk of stiffness of the joint increases the longer it is immobilized. If callus is seen on x-ray at 4 weeks, the cast may be replaced by a removable splint. However, many hand surgeons leave the patients in the cast for up to 6 weeks. In general, the x-rays will not show any callus until about a month after the fracture is healed; therefore the cast is removed before the x-rays confirm that it is healed.
During the period of follow-up, it is common practice to repeat x-rays at about 1 week to make sure the position is still acceptable. Further followup is needed to determine when the fracture has healed and when rehabilitation is complete. The critical time during the period of attempted treatment with casting is the first 3 weeks. The swelling will reduce during this time and the fracture can displace. If the displacement becomes unacceptable, closed treatment may need to be abandoned and surgery pursued. More than 3 weeks after injury, the fracture will start to heal and further displacement becomes less likely.
Undisplaced stable fractures
Where the fracture is undisplaced and stable, non operative treatment involves immobilization. Initially a sugar tong splint is applied to allow swelling and subsequently a cast is applied. Depending on the nature of the fracture, the cast may be placed above the elbow to control forearm rotation. For torus fractures, a splint may be sufficient and casting may be avoided.
Displaced stable fractures
In displaced fractures, the fracture may be manipulated under anaesthesia and splinted in a position to minimize the risk of re-displacement. Typically, this involves injecting local anesthesia into the fracture (hematoma block) possibly combined with intravenous medication. A manual reduction is performed to reposition the displaced distal radius into its preinjury position and maintain this position in a well formed splint or cast.
Displaced fractures in the elderly or those physiologically unable to undergo surgery are treated differently. When the fracture is displaced and there are no plans for a surgery, a short arm cast is placed for only 4 weeks or until the tenderness resolves. A larger cast placed for an extended period of time only slows down recovery in this group of patients.
Following healing and cast removal a period of rehabilitation for recovery of strength and range of motion is necessary. Patients will continue to improve after the fracture for 4 to 12 months.
Closed reduction of distal radius fractures is indicated if non-surgical management is predicted to be successful, and radiographic imaging demonstrates measurements outside the acceptable limits listed below:
- 2-3mm positive ulnar variance
- No carpal malalignment, less than 2mm gap or step deformity in joint
- Neutral dorsal tilt if carpus malaligned, less than 10 degrees dorsal tilt if carpus aligned
- Radial inclination less than 10 degrees
Closed reduction of a distal radius fracture involves first anesthetizing the affected area with a hematoma block, intravenous regional anesthesia (Bier's block), sedation or a general anesthesia.
Manipulation generally includes first placing the arm under traction and unlocking the fragments. The deformity is then reduced with appropriate closed manipulations (depending on the type of deformity) reduction, after which a splint or cast is placed and an X-ray is taken to ensure that the reduction was successful. The cast is usually maintained for about 6 weeks.
Distal radius fractures are often associated with distal radial ulnar joint (DRUJ) injuries, and The American Academy of Orthopaedic Surgeons recommend that post-reduction lateral wrist x-rays should be obtained in all patients with distal radius fractures in order to preclude DRUJ injuries or dislocations.
Closed treatment is frequently unsuccessful in maintaining a good position in adults, because there is frequently comminution of the fracture. Re-displacement and deformity can reoccur with an unacceptable ultimate result.
The American Academy of Orthopaedic Surgeons suggest surgical management for distal radius fractures if post-reduction radiographic imaging demonstrates:
- Radial shortening >3mm
- Dorsal tilt >10 degrees
- Intra-articular displacement
- Step-off >2mm
Risks of non-operative treatment
Failure of non-operative treatment leading to functional impairment, and anatomic deformity is the largest risk associated with conservative management. Prior studies have shown that the fracture often re-displaces to its original position even in a cast. Only 27% - 32% of fractures are in acceptable alignment 5 weeks after closed reduction. In the long term, this increases the risk of stiffness and post traumatic osteoarthritis leading to wrist pain and loss of function. It is because of these findings that many surgeons recommend operative intervention if the fracture is displaced enough to consider a reduction. Ultimately, the fractures that have a closed reduction may return to the position before the reduction is attempted.
Other risks specific to cast treatment relate to the potential for compression of the swollen arm causing carpal tunnel syndrome or compartment syndrome. Carpal tunnel syndrome may be related to the position of the wrist (i.e. excessive flexion) or excess distraction if the wrist is placed in an external fixator. Compartment syndrome is swelling in the muscle compartments, usually in the forearm, leading to severe pain, loss of nerve function and a contracture. Finally, complex regional pain syndrome (reflex sympathetic dystrophy) is a serious complication following injury and is thought to be more common after cast immobilization than after surgery. The provoking factors for regional pain syndromes, however, are very complex but the condition often leads to chronic pain and stiffness.
Despite these risks with non-operative treatment, more recent systematic reviews suggest that when indicated, non-surgical management in the elderly population may lead to similar functional outcomes as surgical approaches. In these studies, there were no significant differences in pain scores, grip strength, and range of motion in patients' wrists when comparing conservative non-surgical approaches with surgical management. Although the non-surgical group exhibited greater anatomic misalignment such as radial deviation, and ulnar variance, these changes did not seem to have significant impact on overall pain and quality of life. These results suggest that as there are decreased functional demands of the wrist in the elderly population, and therefore less symptoms from malunion, there may be less priority to maintain normal anatomy in order to avoid postoperative complications.
Surgery
There are a number of techniques of surgical management, including Open Reduction Internal Fixation (ORIF), external fixation, percutaneous pinning, or some combination of the above. The choice of operative treatment is often determined by the type of fracture, which can be categorized broadly into 3 groups: 1) Partial articular fractures 2) Displaced articular fractures 3) Metaphyseal unstable extra- or minimal articular fractures.
Significant advances have been made in ORIF treatments. Two newer treatment are fragment specific fixation and fixed angle volar plating. These attempt fixation rigid enough to allow almost immediate mobility, in an effort to minimize stiffness and improve ultimate function, although there has been no demonstration of improved final outcome from early mobilization (prior to 6 weeks after surgical fixation). Although restoration of radiocarpal alignment is thought to be of obvious importance the exact amount of angulation, shortening, intra articular gap/step which impact final function are not exactly known. The alignment of the distal radioulnar joint is also important as this can be a source of a pain and loss of rotation after final healing and maximum recovery.
An arthroscope can be used at the time of fixation to evaluate for soft tissue injury. Structures at risk include the triangular fibrocartilage complex and the scapholunate ligament. Scapholunate injuries in radial styloid fractures where the fracture line exits distally at the scapholunate interval should be considered. TFCC injuries causing obvious DRUJ instability can be addressed at the time of fixation.
Prognosis varies depending on dozens of variables. If the anatomy (bony alignment) is not properly restored, function may remain poor even after healing. Restoration of bony alignment is not a guarantee of success, as there are significant soft tissue contributions to the healing process.
Little joint involvement
These fractures are the most common of the three groups mentioned above that require surgical management. A minimal articular fracture involves the joint but does not require reduction of the joint. Manipulative reduction and immobilization was thought to be appropriate for metaphyseal unstable fractures. However, several studies suggest that this approach is largely ineffective in patients with high functional demand, and in this case more stable fixation techniques should be used.
Surgical options have been shown to be successful in patients with unstable extra-articular or minimal articular distal radius fractures. These options include percutaneous pinning, external fixation, and ORIF using plating. Patients with low functional demand of their wrist can be treated successfully with non-surgical management; however, in more active and fit patients with fractures that are reducible by closed means, nonbridging external fixation is preferred as it has less serious complications when compared to other surgical options. The most common complication associated with non-bridging external fixation is pin tract infection, which can be managed with antibiotics and frequent dressing changes, and rarely results in re-operation. The external fixator is placed for 5 to 6 weeks and can be removed in an outpatient setting.
If the fractures are unlikely to be reduced by closed means, open reduction with internal plate fixation is preferred. Although major complications (i.e. tendon injury, fracture collapse, or malunion) result in higher re-operation rates (36.5%) compared to external fixation (6%), ORIF is preferred as this provides better stability and restoration of the volar tilt. Following the operation, a removable splint is placed for 2 weeks, during which time patients should mobilize the wrist as tolerated.
Displaced Intra-articular fractures
These fractures, although less common, often require surgery in active, healthy patients to address displacement of both the joint and the metaphysis. The two mainstays of treatment are bridging external fixation or ORIF. If reduction can be achieved by closed/percutaneous reduction, then open reduction can generally be avoided. Percutaneous pinning is preferred to plating due to similar clinical and radiological outcomes, as well as lower costs, when compared to plating, despite increased risk of superficial infections. Level of joint restoration, as opposed to surgical technique, has been found to be a better indicator of functional outcomes.
Prognosis
Nonunion is rare; almost all of these fractures heal. Malunion, however, is not uncommon, and can lead to residual pain, grip weakness, reduced range of motion (especially rotation), and persistent deformity. Symptomatic malunion may require additional surgery. If the joint surface is damaged and heals with more than 1-2 mm of unevenness, the wrist joint will be prone to post-traumatic osteoarthritis. Half of non-osteoporotic patients will develop post-traumatic arthritis, specifically limited radial deviation and wrist flexion. This arthritis can worsen over time. Displaced fractures of the ulnar styloid base associated with a distal radius fracture result in instability of the distal radioulnar joint and resulting loss of forearm rotation.
Nerve injury, especially of the median nerve and presenting as carpal tunnel syndrome, is commonly reported following distal radius fractures. Tendon injury can occur in people treated both non-operatively and operatively, most commonly to the extensor pollicis longus tendon. This can be due to the tendon coming in contact with protruding bone, as well as with hardware placed following surgical procedures.
Complex regional pain syndrome is also associated with distal radius fractures, and can can present with pain, swelling, changes in color and temperature, and/or joint contracture. The cause for this condition is unknown.
No surgery
In children the outcome of distal radius fracture treatment in casts is usually very successful with healing and return to normal function expected. Some residual deformity is common but this often remodels as the child grows. In the elderly, distal radius fractures heal and may result in adequate function following non-operative treatment. A large proportion of these fractures occur in elderly people that may have less requirement for strenuous use of their wrists. Some of these patients tolerate severe deformities and minor loss of wrist motion very well even without reduction of the fracture. In this low demand group only a short period of immobilization is indicated as rapid mobilization improves functional outcome.
In younger patients the injury requires greater force and results in more displacement particularly to the articular surface. Unless an accurate reduction of the joint surface is obtained, these patients are very likely to have long term symptoms of pain, arthritis, and stiffness.
Epidemiology
Distal radius fractures are the most common fractures seen in adults, with incidence in females outnumbering incidence in males by a factor of 2-3. Men who sustain distal radius fractures are usually younger, generally in their fifth decade (vs. seventh decade in females). The elderly are more susceptible because of the osteopenia and osteoporosis commonly seen in this age group. The majority of these fractures are extra-articular (i.e. not involving the joint).
This is also a common injury in children which may involve the growth plate (Salter-Harris fracture).
In young adults, the injury is often severe as a greater force is necessary to produce the injury.
References
External links
- Orthopaedic Trauma Association Fracture Classification Radius and Ulna
- Wheeless' Textbook of Orthopaedics Fractures of the Radius
Source of the article : Wikipedia
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