Distal Radius Fractures of the Wrist

• Introduction: The Most Common Types of Distal Radius Fractures
• Diagnosing Distal Radius Fractures of the Wrist: Proper Imaging and the Fernandez Classification
• Treatment for Distal Radius Fractures: Closed Reduction, Casting, Surgery, Fixation, and Biologics
• Post-operative Recovery
• Conclusion: An Individualized Treatment Plan for Distal Radius Fractures

Introduction: The Most Common Types of Distal Radius Fractures

The radius is the larger of the two forearm bones linking the hand to the elbow, and is uniquely designed to allow wrist motion and forearm rotation. The end closest to the hand (distal radius) is especially susceptible to fracture because it comprises approximately 80% of the wrist joint surface and bears nearly the full load from a fall on the outstretched hand.

A fracture of the distal radius is one of the most common types of injuries to the skeletal system, and is treated using a variety of different techniques, from casting to pinning to open surgery with plates and screws.

There are a wide variety of fracture patterns, and no single form of treatment applies for all of these fractures. The nature and location of this fracture, compounded by the multi-directional forces we exert on this joint in our daily lives, often requires surgery to achieve proper healing and restore anatomic alignment of this important bone.

There are two common variants of distal radius fractures that are characterized by the direction of forces applied to the wrist during a fall:

• Colles' fractures, the most common type of distal radius fractures, which occur when falling on an outstretched hand, where the hand is extended backward on the wrist, and
  
• Smith’s fractures, which are caused by the opposite mechanism, i.e., when the hand is flexed forward under the wrist.

Many other fracture types exist in addition to these two most common types. Available treatment options depend on the type and severity of the fracture as well as the needs and health of the injured patient, and these options need to be carefully individualized by the treating physician to achieve a satisfactory functional outcome.

“In general, the less invasive treatment - provided it achieves our goals of satisfactory alignment and stable reduction of the fractured bone fragments - results in a better functional outcome and patient satisfaction,” says Dr. Wolfe, chief of the Hand and Upper Extremity service at HSS.

Navigating a patient through a particular treatment plan is a complex task and requires consideration of multiple factors and close attention during the healing phase.

Diagnosing Distal Radius Fractures of the Wrist: Proper Imaging and the Fernandez Classification

A proper diagnosis begins with proper imaging, including initial and follow-up x-rays and possible advanced 3D imaging. Computed tomography (CT) may be employed on occasion to assess the alignment or fragmentation of the joint surface and, less frequently, magnetic resonance imaging (MRI) may be required to rule out concurrent injuries to ligaments or injuries to other bones in the wrist, such as the scaphoid.

It is now our practice to recommend to all women over the age of fifty with a fracture of the distal radius that they consider bone densitometry (DEXA) measurement to assess for the presence of osteoporosis.

A fracture that is displaced, meaning the fracture fragments are out of normal alignment, will require a “reduction,” which refers to an attempt to manipulate the fracture fragments back into alignment. If the reduction is deemed acceptable, periodic images will be taken to ensure that the position or alignment of the fracture fragments does not change during the early phase of healing.

Fractures that are felt to be unstable - due to osteoporotic bone or extensive fragmentation - may be vulnerable to “settling” or loss of reduction, and follow-up imaging may be necessitated as often as every week. More stable fractures may require less frequent follow-up radiographs over the six to eight weeks required for healing.

If the fracture cannot be reduced within an acceptable degree of alignment, or it is deemed grossly unstable and likely to re-displace in plaster immobilization, the physician may recommend surgery to reduce and stabilize the fractured fragments under anesthesia.

The Fernandez Classification

Distal radius fractures, initially classified using one of several anatomic classification schemes that described the number of fracture fragments or disrupted joint surfaces, are increasingly classified by specialists according to the mechanism of injury that caused the break.

Five distinct fracture patterns have been described by D.L. Fernandez, MD, based on the direction and degree of force applied to the radius in the fall:

• Bending: While Colles’ (dorsal) fractures are caused by a “bending” of the bone when the hand is extended backward on the wrist, (see Fig. 1) Smith’s (volar) fractures are caused by “bending” in the opposite direction, with the hand flexed forward under the wrist. (see Fig. 2)
  
  

  Fig. 1 Colles’ fracture of the distal radius.	Fig. 2 Smith’s fracture of the distal radius.

  
  
• Shear: This refers to the action of the bone and its movement as the result of the fracture. As the fracture occurs, the bone shears -- one end of the bone moves in one direction while the other moves in the opposite direction, similar to a highway being sheared by an earthquake (see Fig. 3).
  
  In this so-called “osteo-chondral” fracture (see Fig. 4) the entire joint cartilage is sheared from the end of the radius with its underlying support bone, leaving the shaft of the bone intact. This is a highly unstable fracture, and treatment is difficult because of the small size of the fractured fragments and attached joint cartilage.
  
  

  Fig. 3 Shearing of a highway as the result of an earthquake (photo courtesy of the Smithsonian Institute)	Fig. 4 Similar shearing of the distal radius, known as an osteo-chondral fracture

  
  
• Compression: In falls from a height or other high energy injuries, the hand and wrist bones can be compressed against the flat surface of the distal radius, which yields under the tremendous applied load.
  
  This compressive injury impacts the smaller wrist (carpal) bones into the joint surface of the radius, altering the lattice framework of the inside of the bone and smashing fragments of joint surface into the radius itself.
  
  

  Fig. 5 Compression fracture of the distal radius

  
  
• Fracture-Dislocation: In this high-energy injury, the carpal bones are dislocated from the end of the radius. Along with injury to the supporting ligaments of the wrist, this may result in fragmentation of a portion or all of the joint surface.
  
  Outcome of these injuries depends not only on reconstituting the integrity of the joint surface, but on repair and remodeling of the injured wrist ligaments.
  
  

  Fig. 6 Fracture-dislocation of the distal radius

  
  
• Complex: This is a catastrophic injury, with extensive damage to the joint surface, fragmentation of the widened flare (metaphysis) of the distal radius, and damage to the shaft of the radius and/or the neighboring ulna.
  
  Often, these combination injuries require a combination of treatments to successfully reconstruct the damaged elements.
  
  

  Fig. 7 Complex fracture of the distal radius

Treatment for Distal Radius Fractures: Closed Reduction, Casting, Surgery, Fixation, and Biologics

The scope of treatment for distal radius fractures has changed considerably in recent years. Methods of treatment include casting as well as percutaneous or open surgery, and new and exciting surgical options have developed over the past decade.

Treatment always begins with a closed reduction of a displaced fracture, generally done under local anesthesia and a light sedative, in the emergency department of a hospital.

Closed Reduction

Using various forms of anesthesia to minimize discomfort, the physician manipulates the fracture fragments into proper alignment (reduces the fracture) without making an incision or directly exposing the fracture.

A plaster splint or cast is applied and molded to the patient’s forearm and hand. Often, the plaster may extend above the elbow to help provide additional stability and neutralize the extensive forces that can be generated by natural movements of the arm and forearm.

Following closed reduction, subsequent treatment will be recommended based on an array of patient-related and radiographic factors. The condition and needs of the patient are of paramount importance when considering treatment options, and include the patient’s general medical status, activity level, age, and bone quality.

If a patient’s medical condition permits, the goals of treatment are relatively straightforward: restoration of bony alignment, attainment of a smooth joint surface, and provision of stability until healing.

After determining the mechanism and type of distal radius fracture, its stability can be predicted to some extent based on five important factors:

• The degree of fragmentation of the bone
• The amount of displacement that occurred at the time of injury
• The integrity of the three columns of the wrist, including the ulna bone
• The age of the patient (a relative barometer for osteoporosis), and
• The integrity of the joint surface.

After considering these factors, as well as the general health and needs of the patient, a surgeon will decide whether a fracture is likely to be stable or unstable following reduction, and will recommend one or more of the following treatment options:

Casting

Casting provides external stability to the forearm and hand by the application of gentle pressure to the skin and underlying soft tissues. This provides a rigid mold and contains the reduction in proper alignment during the healing period. If the fracture is stable and has been successfully realigned by the reduction, casting may be the only treatment necessary.

Casts will need to be removed and replaced several times during the healing period to insure snug and secure support of the fracture. Casts may be applied either “above elbow” or “below elbow” and may include the thumb or not, depending on the particular type of injury and physician preference.

Casts are generally made from plaster early in the treatment, which allows for some degree of swelling, and the more rigid and lighter-weight fiberglass material during later stages of healing.

Fig. 8 Casting for a stable distal radius fracture

Surgery

When surgery is necessary, there is usually a two week window of opportunity before early bone healing begins. Patients may seek a second opinion during this period to explore their options, and Dr. Wolfe feels that the additional time until surgery does not affect ultimate outcome:

When one considers the gravity of the injury, its immediate and potential long-term impact on one’s activities and livelihood, the amount of ongoing research, and the number of recent changes in treatment of these injuries, it is important that the patient have a thorough understanding of the treatment options, expected outcomes, and potential complications of treatment.

Internal Fixation (plates, screws, pins)

A common form of internal fixation involves an open surgical technique in which an incision is made over the fracture and a stainless steel plate with screws is placed to align the bone ends and prevent displacement or loss of reduction.

Fig. 9 Internal fixation of a distal radius fracture

Advantages of internal fixation include:

• increased stability
• strategic placement of implants
• the lack of a need for an external device
• less obtrusive casting and potential earlier use of the hand

This may not be suitable for all fractures -- possible complications of this technique include:

• loss of fixation
• improper positioning of the plate or screws
• infection
• the need for hardware removal
• nerve injury
• tendon injury or rupture
• stiffness

Percutaneous fixation with pins and casting

Some types of fractures, while unstable in a cast alone, require only the addition of one or more pins to create a stable situation and enable treatment with a cast. The pins can be placed without the need for an incision and are done in the operating room under a regional anesthetic. The wrist is then placed in a cast until healing, at which time the pins are removed and therapy begun.

Advantages of percutaneous pin fixation include:

• adequate stability for closed treatment
• no need for permanent hardware implantation
• minimal soft tissue or bony complications
• less painful procedure
• minimal scarring and no surgical incision

This may not be suitable for all fractures -- possible complications of this technique include:

• loss of fixation
• settling / loss of reduction
• pin infection
• re-operation
• nerve injury
• tendon injury
• stiffness

External Fixation

External fixation is a time-honored technique that involves using an external frame holding pins placed in the bone through small incisions on both sides of the fracture.

“While associated with a high rate of complications during widespread use thirty years ago,” notes Dr. Wolfe, “clinical and basic research has yielded newer techniques and devices, dramatically reducing complications and improving clinical outcomes with this technique.

In fact, recent large-scale randomized clinical studies suggest improved functional and clinical outcomes for selected fractures when compared with more invasive surgical techniques.”

Using the technique of augmented external fixation, the fixator (see Fig. 10) is generally applied in conjunction with percutaneous pins and bone graft to directly support the broken fracture fragments and reduce the need for traction to be applied by the fixator device. This allows the wrist to be placed in a comfortable position and the fingers to be used for resumption of lightweight daily activities almost immediately after surgery.

When the wounds are healed in 10-12 days, patients are allowed to shower and get the wounds wet, provided they keep the pin sites cleaned regularly.

Fig. 10
Example of external (percutaneous) fixator for distal radius fracture

Advantages of external fixation include:

• a proven, time-honored technique
• minimal soft tissue disruption/minimally invasive
• all hardware is removed (no concerns for airport security or tissue response)
• skin incisions result in minimal scarring
• bone graft may be used to support the joint surface
• equivalent or improved clinical, radiographic, and functional outcomes in selected fractures

Disadvantages of external fixation include:

• the presence of a bulky metal or plastic frame about the wrist
• protrusion of pins from the skin surface and the need for pin care
• inability to begin motion therapy of the wrist joint for several weeks after surgery

Possible complications include:

• wrist and hand stiffness
• pin tract infection
• nerve injury
• settling / loss of reduction
• re-operation

Biologics

New biologic agents which enhance bone healing hold much promise in treating fractures when used along with one of the treatments mentioned above.

On the near horizon, researchers, scientists, and clinicians expect biologic agents to augment the bone healing process to such a degree that a four-week recovery period may be realized for distal radius fractures, substantially shortening the current 6-8 week outlook. This may enhance the future applicability of some of the percutaneous methods of fracture treatment.

Periodically, clinical trials of new agents are being tested by Dr. Wolfe and his colleagues at Hospital for Special Surgery and elsewhere throughout the country.

Post-operative Recovery

Casting

The rule for bone healing in general is to expect a six-week period to ensure proper bone strength. One-two additional weeks of support in a removal plastic splint is generally advised. A stable fracture may be treated with a combination of casting and splinting throughout this healing period.

Internal Fixation

In most cases, a patient who has undergone internal fixation surgery for a distal radius fracture may begin gentle wrist range of motion within 1-2 weeks of surgery, after which time a removable splint is used to support the hand.

The plate that was surgically placed inside the arm/wrist at the time of surgery may be left in place or removed at a later date.

External Fixation

The external frame and pins are usually removed sequentially, beginning 3-6 weeks after surgery, followed by a few additional weeks of removable splint wear.

Conclusion: An Individualized Treatment Plan for Distal Radius Fractures

Fractures of the distal radius are very common, and are treated using either casting or surgical techniques such as internal and external fixation. There are nearly as many ways to treat a distal radius fracture as there are distal radius fractures.

In other words, there is no one treatment that is effective for all types of fractures. Each fracture requires individual treatment customized to deal with the specific characteristics of the fracture.

“An important consideration when treating a fracture of the distal radius,” stresses Dr. Wolfe, “is to assess its ‘personality’ and customize one’s treatment to best match its personality.”

For more information please visit www.hss.edu/conditions_distal-radius-fractures-of-the-wrist.asp