Injury of the Wrist

Because of the large role the wrist plays in daily activities, it is often prone to stress and injury that results in pain and instability.

The proximal bones of the wrist - the scaphoid, lunate, and triquetrum - have no muscular attachment. With the help of many strong ligaments, their main purpose is to stabilize the wrist joint. Damage to any of these ligaments that bind the proximal bones together can result in a malalignment of the carpal bones, which, if left untreated, could cause abnormal wear and tear and eventually lead to osteoarthritis.

The most common ligamentous injury of the wrist is Scapholunate Instability. It is diagnosed when two of the three main ligaments that bind the Lunate and Scaphoid bones are significantly damaged. These ligaments include the Volar radioscapholunate ligament, the scapholunate interosseous ligament, and the dorsal scapholunate ligament.

Initially the symptoms of a ligament injury may result in pain, weakness and a sense of "giving way." Often times the pain will subside after a few days even though carpal instability exists - unfortunately leading patients to believe a physical examination and subsequent treatment unnecessary.

Those at Risk
Ligament injuries and carpal instability most often occur in the young and middle aged, because they are more active and have stronger bones. Injury to the increasingly fragile bones of older patients most often results in a fracture rather than soft tissue damage.

Diagnosis
With the right imaging and careful assessment, modifications in carpal bone contours or positions following an injury will confirm carpal instability. Early treatment is essential in preventing the development of osteoarthritis.

Treatment
If diagnosed early enough a minor injury can be addressed with conservative treatment. This consists of splinting and the use of NSAIDs (non steroidal anti inflammatory drugs). But if the injury is determined to be severe, surgery is necessary to correct the alignment.

If carpal insufficiencies are left untreated, further shifts of the carpal bones may occur. In the case of scapholunate instability, the continuation of shifting can eventually lead to a condition known as scapholunate advanced collapse, or SLAC - and wrist fusion may be required.

Distal radioulnar joint (DRUJ) injuries can occur separately or in conjunction with distal radius fractures and both-bone forearm fractures. In fact, nearly 60 percent of forearm fractures adversely affect the DRUJ.

The ulna is the stationary, stable anatomical point of reference for rotation of the forearm - around which the radius rotates in pronation and supination. The distal and proximal radioulnar joints form the forearm joint. Mobility and stability of the distal radioulnar joint is accomplished with fully congruent articulating surfaces and radioulnar ligaments that are strong and secured.

Following a distal radius fracture, the congruency is lost and stabilizing ligaments tear. DRUJ injuries are classified as stable, partially unstable (subluxation), and unstable (dislocation) patterns - depending on the injured structures and clinical findings.

Diagnosis
The nature of the accident and area of pain is the first indication of possible DRUJ damage. A radiograph and possible CT scan can further identify the extent of the damage and area of instability. Accurate assessment of the stability of the DRUJ is challenging - particularly when late instability is suspected after the associated fractures have healed. A series of scans with the forearm in pronation, neutral and supination are recommended in order to compare the injured and uninjured joints.

Exploratory arthroscopy can also help identify stable and partially unstable lesions.

Treatment
Once any associated fractures are addressed with internal fixation the remaining instability of the DRUJ is assessed. Treatment depends on whether an injury is a simple or complex dislocation. Reduction is the first course of action for a simple dislocation - accomplished with either direct pressure over the ulna with a period of mobilization or a period of directed mobilization, depending on the location.

In complex dislocations it may be necessary to reattach massive tears with the use of anchor sutures or pull-out wires. Depending on the level of instability, additional fixation of the joint may also be required - generally using Kirschner wires.

A small meniscus located on the ulnar side of the wrist (the side opposite the thumb), the triangular fibrocartilage complex (TFCC) serves as a connective site for ligaments, as well as a cushion between the carpal wrist bones and the end of the forearm. It is damaged when a strong compression and shearing force is applied to it. Since the wrist is not a weight-bearing joint, the pain and functional discomfort are minimal.

Those at Risk
While a fall on an outstretched arm could result in such an injury, athletes involved in activities requiring a large amount of wrist motion such as swinging a baseball bat, throwing a ball or other object, as well as gymnastics and other events requiring wrists to balance weight are most at risk.

Diagnosis
Patients experiencing TFCC damage may experience discomfort on the ulnar side (little finger) of the wrist, increased pain when the hand is rotated away from the thumb and a popping sound. While a physical examination and description of the accident that resulted in the injury will indicate the possibility of TFCC damage, an MRI will confirm the diagnosis.

Treatment
Depending on the severity of the damage either conservative treatment, arthroscopy or a surgical procedure to repair a tear is recommended.

Conservative treatment consists of rest and change in activity in order to reduce stress to the affected hand. It may also include casting of the wrist and the use of non-steroidal anti-inflammatory medications (NSAIDs).

If pain persists following conservative treatment, or if there was a severe tear, wrist arthroscopy may be performed. Chronic tears may require an excision of the tear.

A wrist sprain occurs when ligaments that support the wrist and connect the bones to each other are stretched or torn. This often happens when an outstretched hand is used to break a fall. Individuals suffering from a wrist sprain may experience pain and swelling around the wrist. The area may be sensitive and warm, with visible redness or bruising. Those suffering from a wrist sprain have limited ability to move the wrist.

An x-ray is generally taken to ensure that no bones are broken. While not frequently performed for this type of injury, occasionally a magnetic resonance imaging (MRI) scan may be done in order to determine if a more severe ligament injury exists.

Risk Factors
Those individuals involved in sports, as well as those experiencing poor coordination, balance, flexibility and strength in muscles and ligaments, are at greater risk for wrist sprains.

Treatment
Treatment options for wrist sprains are generally non-invasive and may include a period of rest from rigorous hand activities. Cold compression is used to reduce pain and swelling - and elevation helps drain fluid and reduce swelling. Inflammation reducing medication such as Ibuprofen, Naproxen, Acetaminophen (Tylenol) and aspirin, may also be prescribed.

Occasionally a brace or cast may be placed on the wrist to ensure immobilization. Surgery, though rare in such cases, is sometimes necessary to repair a ligament that has completely torn - or address an associated fracture.

Rehabilitation
Following a period of rest, patients then begin a series of exercises, in order to restore flexibility, range of motion and wrist strength. While some of the exercises focus on strengthening all muscles surrounding the area of vulnerability, others are developed specific to the patient's lifestyle and can fit easily into daily activities.