Wrist Fracture & Dislocation
Distal Radius Fractures
Also called a Colles fracture, distal radius fractures are among the most common type of fractures, affecting the distal end of the radius bone in the forearm. It most often occurs when the arm is used to break a fall but may also occur as a result of a direct trauma or accident.
The radius, which is the forearm bone that runs between the wrist and the elbow, becomes rigid when it is extended to break a sudden fall. The extreme compression and twisting force results in a fracture at the wrist.
A fracture to the distal radius causes immediate pain, and there is an obvious deformity of the wrist. This may be followed by swelling, stiffness and loss of motion. Bruising may also be present.
Distal radius fractures are most commonly seen in action sports athletes involved in such activities as motocross racing and cycling. They are also seen to a lesser extent in those involved in a trauma such as a car accident, as well as roller blade or skate boarding accidents. Distal radius fractures are also common in patients over the age of 60, as a result of osteoporosis. The decreased bone density of patients suffering from this condition increases risk of damage in even a minor fall.
Distal radius fractures are also common in patients over the age of 60, as a result of osteoporosis. The decreased bone density of patients suffering from this condition is vulnerable in even a minor fall.
Diagnosis and Treatment
A thorough examination and discussion of the manner in which the injury occurred is part of determining diagnosis. The appearance of the wrist is also a strong indicator of this type of fracture. An x-ray will confirm the diagnosis.
A fracture may be either displaced or nondisplaced. A displaced fracture means that the two bone parts are not in proper alignment. A nondisplaced fracture means that the bone, while fractured, remains aligned.
The treatment plan selected will depend on the severity of the fracture and whether it is displaced or nondisplaced. The primary goal in treating a fracture is to ensure that the bones heal in the correct alignment. Nondisplaced fractures may simply require bracing and anti-inflammatory medication. Displaced fractures may require surgery in order to ensure that the dislocated bones are replaced in their normal anatomic positions. This is called reduction. Reduction may be done either closed (no incision) or open (requiring an incision). The type of fixation used to hold the bone in the correct position is determined based on the condition of the patient, lifestyle, and severity of the injury. Fixation can be either internal or external.
The scaphoid bone is one of the strongest and most difficult bones to break in the wrist, yet it accounts for nearly 60 percent of all wrist fractures. Almost always the result of an extreme force, a scaphoid fracture is a break in the small scaphoid bone located in the wrist joint.
The scaphoid bone, which is shaped like a cashew and located on the thumb side of the wrist, near the lower arm bones, requires twice as much force to break than one of the larger forearm bones. Eighty percent of the surface of the scaphoid bone is covered by articular cartilage, and it functions much like a ball bearing in the wrist joint.
A scaphoid fracture requires special attention, because of the vulnerable location of its blood supply. The blood supply for a scaphoid bone enters from the top. Since most fractures occur in the middle or lower portion of the bone, the supply is interrupted and fails to reach the injury and promote adequate healing.
An undetected scaphoid fracture that results in an interrupted blood supply, can lead to avascular necrosis. Avascular necrosis can cause the bone to crumble and the wrist joint to be destroyed.
When a scaphoid fracture occurs, there may be pain and tenderness on the thumb side of the wrist. Motion is painful and swelling may be evident on the back and thumb side of the wrist. Often times injuries sustained from high speed or force, such as in football, a fall at high speed, or an auto accident will result in a complex injury. A complex injury involves companion fractures and ligament injuries as well. A thorough examination will determine whether or not the injury is complex.
Generally this type of injury occurs when the wrist joint of an outstretched hand hyperextends. Men are much more likely to fracture this bone than a woman, because of the forceful activities in which they are often involved and the larger weight ultimately falling or pushing against joint.
Scaphoid fractures generally occur in men between the ages of 20 and 40 years. It is a common injury in traditional as well as extreme sports though can also occur as a result of an automobile accident.
Diagnosis and Treatment
Because the scaphoid bone is located inside the wrist joint, rarely do scaphoid fractures result in an obvious deformity - as seen in many bone fractures - and may be mistaken for a simple wrist sprain. And while there may be swelling, it can subside after a few days. Therefore, the diagnosis of a scaphoid fracture is often delayed for weeks and sometimes months.
Recognizing that the mild symptoms may be deceiving and understanding the severity of a severed blood supply often associated with a scaphoid fracture, a hand specialist will perform a thorough physical examination and confirm diagnosis with x-ray and magnetic resonance imaging - which will also reveal any other tissue damage. A bone scan can also help in a diagnosis days following an injury.
Treatment will depend on the severity of the fracture. Incomplete and nondisplaced fractures are initially treated with compression and limb elevation in order to reduce swelling. This is then followed by a period of immobilization, with either a splint or short arm cast for six weeks to three months - depending on the severity of the break and associated injuries.
While cast treatment works best for incomplete fractures that do no extend across the entire bone, casting alone does not always promote healing and may also impede the rapid return to sports by restricting the ability to regain strength and range of motion.
Complete scaphoid fractures and those nonresponsive to casting may require arthroscopic or surgical repair, in order to stabilize the bone with a scaphoid bone screw Kirshner wire or other internal fixation. Fractures with a severe ligament injury also require surgical repair, in order to stabilize the wrist and prevent the collapse of the wrist bones - which would lead to deterioration and permanent stiffness of the wrist joint.
A fresh fracture (a fracture that is less than two to four weeks old) that is displaced or unstable requires surgery and the use of a fixation device for stabilization. A fracture that is not first stabilized is unlikely to heal in a cast.
Nonunions and Old Fractures
If a scaphoid fractures remains undetected and untreated, the prolonged unstable joint environment it creates will ultimately lead to severe arthritis and require joint fusion or joint replacement. A nonunion, a bone that has failed to heal and old fractures require special treatment.
Sometimes a bone graft is necessary to prompt the healing of an old scaphoid bone fracture that never healed properly. This is accomplished by taking a small piece of bone from the iliac portion of the pelvic bone. A Herbert scaphoid screw is used to stabilize the bone graft and the patient is placed in a cast for approximately four weeks. Occasionally a fresh fracture will also require a bone graft when there are a number of pieces, or it is "comminuted."
Following a period of casting and immobilization, range of motion exercises represent the first critical phase of rehabilitation. These exercises are very important for limbs that have been immobilized - as joints can quickly become stiff and muscles weakened. A thumb spica splint may be used for protection during this phase, until range of motion and strength of the wrist flexors and extensors improve. Supination, pronation, and grip strength exercises are progressively added.
If a long-arm cast is used and flexion contractures are evident, physical therapy is recommended and a program specific to the patient is developed.
For the first several days following surgical repair with internal fixation patients are encourage to keep the wrist elevated, in order to reduce swelling, and maintain clean, dry bandages. Swelling is further reduced with cold compressions. Analgesic medications may be prescribed to help minimize postoperative pain.
Following an arthroscopic procedure, there is a period of immobilization before range of motion exercises begin. This may vary depending on certain patient factors and the condition of the wrist following surgery. Patients are then given progressive strengthening exercises for the wrist flexors and extensors - with supination, pronation and grip strength exercises gradually added.
Once a fresh fracture is stabilized with fixation, the patient can return to sports in approximately eight weeks. Though following a nonunion and bone grafting, the recovery process may last up to three months.
Hamate Hook Fractures
Also called "hook fractures," hamate hook fractures are the most common type of hamate fractures, which frequently results when a handle sharply impacts the proximal hypothenar palm - most often occurring in tennis, golf, and baseball. These types of fractures may also result from a fall on an outstretched wrist or part of widespread injury sustained in an automobile accident.
The hypothenar muscles attach to the hook of the hamate. When it is fractured through the base, these muscles stress the fracture in different directions - creating an unfavorable environment for healing and producing a nonunion. And because the hook of the hamate borders the Guyon's Canal, the ulnar artery and nerve traveling through the canal often sustain damage as well.
Much like scaphoid fractures, hamate hook fractures are not always evident on a standard x-ray and require special radiographic imaging to confirm diagnosis and determine the extent of the damage. They are also vulnerable to complications, because of their predisposition to nonunion.
In order to prevent future tendon chafing, these types of fractures are generally treated with excision of the hook fragment and smoothing of the base.