The bones of the wrist have no muscular attachment. Wrist stability comes primarily from many strong ligaments, all with the primary goal to stabilize the wrist joint. Damage to any of these ligaments may result in movement of the carpal bones (scaphoid, lunate, triquetrum) resulting in an unstable environment, or carpal instability.

Scapholunate Instability is among the most common ligamentous injury of the wrist. It is the result of significant damage to two of the three main ligaments that bind the lunate and scaphoid bones. These ligaments include the volar radioscapholunate ligament, the scapholunate interosseous ligament, and the dorsal scapholunate ligament.

The early symptoms of a ligament injury resulting in carpal instability include pain, weakness and a sense of "giving way." Often times the pain will subside after a few days even though carpal instability persists. Unfortunately, this reduction in pain leads patients to believe that a physical examination and subsequent treatment plan are unnecessary.

If left untreated, carpal instability could cause abnormal wear and tear on the joint and eventually lead to osteoarthritis.

Risk Factors
Carpal instability and ligament injuries prompting this condition occur more often in the young and middle- aged, as a result of their level of activity and bone strength. Injury to the increasingly fragile bones of older patients most often results in a fracture rather than soft tissue damage and discreet instability.

Treatment
Carpal instability is confirmed following a physical examination, assessment of the manner in which the injury was incurred and imaging scans.

Carpal instability, if left untreated, can result in further shifting of the carpal bones. In the case of scapholunate instability, the continuation of shifting can eventually lead to a condition known as scapholunate advanced collapse, or SLAC.

A distal radioulnar joint (DRUJ) injury may be the result of ligamentous disruption or fracture, which compromises joint stability.

A DRUJ injury can occur separately or in conjunction with distal radius fractures and both-bone forearm fractures. In fact, nearly 60 percent of forearm fractures negatively impact the DRUJ.

The radius rotates around the ulna, a stable and stationary anatomical point of reference for rotation for the forearm. While the distal and proximal radioulnar joints form the forearm joint, mobility and stability of the distal radioulnar joint is accomplished only with fully congruent articulating surfaces and radioulnar ligaments that are strong and secured.

Risk Factors
Those involved in activities or sports that put the forearm at risk of strong force or impact or those suffering from osteoarthritis or rheumatoid arthritis are likely to suffer from DRUJ pain or instability.

Diagnosis and Treatment
Following a thorough review of patient history and a physical examination, a radiograph and possible CT scan can further identify the extent of the damage and area of instability. Accurate assessment of DRUJ stability, particularly when late instability is suspected after the associated fractures have healed, requires a detailed assessment.

Exploratory arthroscopy may be used to help identify stable and partially unstable lesions.

If a DRUJ injury occurred as the result of a fracture, the associated fracture is first addressed. Depending on the level of joint instability, additional fixation of the joint may also be required.

The triangular fibrocartilage complex (TFCC) is a small meniscus located on the ulnar side of the wrist and serves as a connective site for ligaments, as well as a cushion between the carpal wrist bones and the end of the forearm. A strong compression or force can damage the TFCC.

TFCC tears cause minimal pain and discomfort, because the wrist is not a weight-bearing joint.

Risk Factors
While TFCC tears can occur during an accident or fall on an outstretched arm, athletes involved in activities requiring a large amount of wrist motion such as swinging a baseball bat, throwing a ball, or balancing as in gymnastics are at greatest risk.

Diagnosis and Treatment
TFCC damage may cause discomfort on the ulnar side (little finger) of the wrist and increased pain when the hand is rotated away from the thumb. There may also be a popping sound during movement. Following a thorough review of patient history, physical examination and assessment of the manner in which the injury was incurred, a MRI will confirm the diagnosis.

Treatment will depend on the severity of the damage and may involve conservative treatment, arthroscopy, or surgical repair.

Conservative treatment consists of rest and change in activity in order to reduce the stress on the affected hand. It may also include casting 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.

When the ligaments responsible for connecting the wrist bones and supporting the wrist are stretched or torn, it is called a wrist sprain. 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 and have limited range of motion. The area may also be sensitive and warm, with visible redness or bruising.

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.

Diagnosis and Treatment
Generally a description of the pain followed by an x-ray to ensure that there are no broken bones will determine diagnosis. Occasionally a magnetic resonance imaging (MRI) scan may be done in order to determine if a more severe ligament injury exists.

Conservative treatment is generally all that is required for wrist sprains and may include a period of rest from inflammatory hand activities. Cold compression is used to reduce pain and swelling. Elevation helps drain fluid and reduce swelling as well. Medication may also be prescribed in order to reduce inflammation.

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.