What is Wrist Instability?
The wrist is a complex and flexible part of the body. It’s made up of many small joints, which allow your wrist to move in different ways such as side to side, up and down, and in a circular motion. However, because of its structure and flexibility, the wrist is quite susceptible to injuries like sprains and strains. Despite this, it is quite durable and can withstand force from various directions.
Your wrist stays balanced due to the ligaments, which are like strong bands connecting the bones. High pressure or force can disrupt this balance and cause instability, meaning the wrist becomes less secure and can move in ways it shouldn’t.
The kind of instability in the wrist can be different depending on the type and severity of the injury to the ligaments or bones. If the instability only occurs when the wrist is moving, it’s called ‘dynamic’ instability. If the wrist is unstable even when it’s not moving, it’s considered ‘static’ instability. The two most common forms of instability are Radiocarpal (involving the main wrist joint) and mid-carpal (involving the middle part of the wrist). Treatment for wrist instabilities can vary, from wearing wrist braces to repair surgery, depending on how severe the instability is.
What Causes Wrist Instability?
Acute Ligament Instability happens when someone experiences a trauma or an injury. This can occur when an indirect force is applied to the ligament, causing severe instability.
Acute Bony Instability, on the other hand, is generally caused by bone fractures. This happens when a strong force or impact breaks the bone, leading to an unstable situation.
Chronic Instability commonly develops from repetitive minor injuries or from the lingering effects of a past injury, like a fracture in the distal radius (which is the larger of the two bones in your forearm).
Systemic illnesses can also result in joint instability. Conditions like avascular necrosis (a disease that results from the death of bone tissues due to lack of blood supply) of the scaphoid (one of the small bones in the wrist), or rheumatoid arthritis (a chronic inflammatory disorder that affects the joints).
Neurological conditions can lead to joint instability often through the development of neurogenic arthropathies. This means that a disease of the nervous system can affect the joints in a way that’s similar to a condition called Charcot joints. Syringomyelia, a rare disorder in which a cyst forms within the spinal cord, is an example of such a condition.
Congenital Instability means someone is born with a condition that begins during pregnancy and leads to instability. An example is Madelung deformity, which causes a misalignment in the forearm (radius, ulna) and wrist bones, predisposing the person to progressive arthritis and instability.
Risk Factors and Frequency for Wrist Instability
- A study by O’Brien found that 44% of cases showed signs of carpal instability two years after an injury.
- Andersson’s research indicated that in 22% of cases, malunion or stopped growth were the reasons for secondary instability in the distal radio-ulnar joint (an area in the wrist).
- J B Tang reported that 30.6% of patients were found to have an incidence after the fracture of the lower end of the radius bone (one of the bones in the forearm).
- Irregular Scapholunate angles, a specific measurement used to assess wrist health, were observed in 39% of patients when they first presented and in 35% of patients after receiving treatment for fractures in the distal radius.
- Reports suggest that the rates of instability in the lower radial-ulnar joint following fractures in the distal radius fall between 10% and 19%.
Signs and Symptoms of Wrist Instability
Commonly, wrist injuries are the result of a sudden trauma such as a fall on an outstretched hand, with the wrist bent or twisted. Signs of injury typically include:
- A sudden, painful clicking or popping sensation
- Swelling or deformation
- Pain when in a push-up position
- Weaker grip
- The feeling of the wrist buckling or giving out
- Numbness or ‘pins and needles’ feeling, primarily in the area serviced by the median nerve
A doctor will carry out a physical examination to check for these signs:
- Tenderness in the so-called ‘snuffbox’ region of the wrist which might indicate a potential scaphoid fracture
- Certain tests for Dorsal Intercalated Segment Instability (DISI), including pain with certain wrist movements, tenderness at specific points in the wrist, and the Watson Test
- Tests for Volar Intercalated Segment Instability (VISI) which involves assessing pain and clicking in the lunotriquetral joint during active and passive sideways wrist movements
- The presence of Carpal Instability Nondissociative (CIND) symptoms, such as an unexpected shift in the alignment of the wrist bones during wrist movements
- Painful compression of the bones in the distal radioulnar joint (where the two forearm bones meet) and the Piano Key Test
Further, the person might exhibit overall looseness in the wrist ligaments. A positive Tinel sign – tingling sensation when the median nerve is tapped – could be present if the median nerve is compressed.
Testing for Wrist Instability
Your doctor will want to conduct several tests if they suspect you have a condition that involves your connective tissues. This will often start with routine lab tests to establish a baseline of your overall health. They may then conduct more specialized tests, such as checking for the rheumatoid factor or other indicators related to connective tissue issues.
If your doctor suspects inflammation or infection, they may look at two markers in your blood: C-reactive protein (CRP) and white cells (WC). High levels of these in the blood can suggest chronic inflammation or infection is present.
In addition to blood tests, your doctor may want to take a closer look at your wrist using various imaging techniques. They will often start with a series of X-rays taken from different angles (anterior-posterior, lateral, clenched fist, scaphoid, radial and ulnar deviation, flexion and extension views). These images can help your doctor identify any signs of instability in your wrist.
If the X-rays suggest that there may be issues, your doctor may suggest other forms of imaging for a clearer view. For example, a CT scan can be used to examine chronic distal radio-ulnar joint (the joint between the forearm bones), complex fractures, misalignments and non-unions (fractures that didn’t heal correctly).
If ligament injuries or suspected fracture-dislocations need to be diagnosed, an MRI comes handy. This can provide a detailed image of the tendons and ligaments in your wrist.
Lastly, if your doctor isn’t able to identify the problem using imaging, you may need to undergo a procedure called arthroscopy. This involves inserting a small camera into your wrist to inspect the structures inside. This procedure is more invasive than the others but is also considered the “gold standard” for diagnosing ligament-related injuries.
Treatment Options for Wrist Instability
If you have a Dorsal Intercalated Segment Instability (DISI), a condition where bones of your wrist aren’t correctly aligned, treatments aim to reduce pain and maintain wrist function. For minor injuries or chronic injuries without further complications, pain medication and limited hand movement using immobilization devices may be recommended. Even if you’re not feeling any pain, treatments can still help manage the instability. These treatments usually consist of patient education, devices that keep your wrist steady (splints), drugs to lower inflammation (anti-inflammatories), and short periods of hand therapy.
In some stubborn cases, surgery might be needed, although the results can’t always be predicted. There are several surgical procedures available to correct the problems in the ligaments, bones, and tissues of the hand and wrist, each with their specific advantages.
Various fusions techniques are also available. They are techniques used to join together certain bones in the wrist to reduce pain and maintain some level of flexibility and movement. An example is the triscaphe arthrodesis, which joins three bones in the wrist and can help retain around 80% of the wrist’s normal movement.
Volar Intercalated Segment Instability (VISI) can also be managed with several treatments. Upper-arm strength exercises, over-the-counter pain relievers, and wrist braces are typical options. For more severe cases, surgeries like capsulorrhaphy, which shrinks the wrist joint capsule, reefing techniques, and others may be implemented. Commonly, four-corner fusion and radiolunate fusion are used, where certain bones in your wrist are permanently joined together.
For perilunate dislocation, a serious injury that happens when one of the wrist bones (the lunate) is pushed out of place, the preferred treatment is immediate reduction and subsequent fixation and ligament reconstruction. This means that doctors will put the bone back in place and use special tools to keep it there until it heals. If the injury is older than 8 weeks, proximal row carpectomy is typically advised. This is a procedure where some bones in the wrist are removed to alleviate pain and restore function.
Adaptive instability, which happens when the ligaments (bands of tissue) that hold the bones together stretch out or tear, is typically corrected with what’s called an osteotomy. This is a surgical procedure that realigns the bones of your wrist.
In cases of distal radio-ulnar joint instability (DRUJ), where the joint at the end of two forearm bones (the radius and ulna) becomes dislocated or unstable, a variety of treatments can be considered. If the injury is stable, the management usually involves reduction and pinning, where the surgeon puts your bones back in place and secures them as they heal. For more severe injuries, where the cartilage disc between the radius and ulna is damaged, the surgeon may resort to arthroscopic or open debridement. This is a procedure that cleans out the damaged parts of the joint. For some specific complications where the bones of the wrist painfully collide, a procedure called distal ulna resection surgery (DURS) can be done where part of the ulna bone is removed.
What else can Wrist Instability be?
If your wrist hurts, makes a clunking noise, or feels weak, it might be due to various issues. However, here is a list of common conditions that could be causing these symptoms:
- Painful ganglion (a fluid-filled lump associated with a joint)
- Carpal fractures (broken wrists)
- Stress fractures (tiny cracks in a bone)
- Ulnar impaction syndrome (wrist pain due to the longer ulna bone)
- Essex-Lopresti injuries (injuries to the forearm)
- Galeazzi fractures (broken bones in the forearm)
- Kienbock disease (a condition that interrupts the blood supply to one small wrist bone)
- Tendinitis (inflammation or irritation of a tendon)
What to expect with Wrist Instability
The results of hand injuries affecting the palm side (volar carpal instability) are generally worse than injuries affecting the back of the hand (dorsal instability). A person can usually expect a good outcome following treatment of an acute (recent) instability, which usually involves reducing (or setting) the dislocation and fixing it in place.
Over a period of seven years, it was found that 83 percent of patients who received treatment within three months of tearing a critical ligament in the wrist — the scapholunate ligament — remained symptom-free and their injured joint remained in a healthy state.
Another study showed that those who receive surgical treatment quickly after an injury generally fare better in terms of survival rates and improved physical functionality in comparison to those who are treated for chronic (long-standing) injuries.
However, a specific type of surgery known as lunotriquetral arthrodesis, is associated with more complications and a higher likelihood that further surgery will be required.
In contrast, chronic injuries and fractures that have been ignored or not treated properly can lead to poor outcomes such as arthritis, a need for the wrist to be fused in position, or the need for a procedure called a proximal carpectomy, which involves some of the wrist bones being removed.
Possible Complications When Diagnosed with Wrist Instability
Perilunate dislocations can lead to a variety of complications such as:
- Compression of the median nerve
- Compartment syndrome, a painful condition that arises from an increase in pressure in a muscle compartment
- Decreased blood supply to the lunate, a small bone in the wrist (lunate ischemia)
- Loss of blood flow causing the lunate bone in the wrist to die (avascular necrosis)
Radiocarpal instability, a condition that affecting the wrist’s ability to move and rotate, can lead to:
- Acute carpal tunnel syndrome, a symptom caused by pressure on the median nerve
- Stiffness in the wrist
- Arthritis in the wrist joint
- Chronic instability or instability over time
- Deformities in the wrist
In the condition known as DISI (Dorsal Intercalated Segment Instability), one might experience:
- Advanced scapholunate collapse, which is a nonunion or failure to heal
- Stiffness in the wrist joint
- Arthritis in the wrist joint
- Weakness in the wrist grip
VISI, or Volar Intercalated Segment Instability, can result in:
- Stiffness in the wrist
- Loss of the ability to perform dart-throwing motion
- Chronic instability in the wrist
And lastly, problems associated with the distal radioulnar joint, or DRUJ, may include:
- Distal radioulnar arthrosis, which is arthritis in the joint where the two forearm bones meet
- Chronic pain in the wrist joint
- Pain during rotational wrist movements like supination (rotating palm upward) and pronation (rotating palm downward)
Recovery from Wrist Instability
After a medical procedure to correct a particular condition (reduction), a support gear (orthosis) is placed on the patient for six weeks. This gear aids in the healing process.
Following these 6 weeks, the patient will start doing range-of-motion exercises to help the injured wrist heal in an organized manner. These exercises will help in mending the ligaments, which are tough elastic bands of tissue connecting the bones in your wrist.
The so-called ‘dart-throwing’ motion is a crucial movement of the wrist, and it is particularly important during the healing process.
Two muscles in the forearm,
the flexor carpi ulnaris and the extensor carpi ulnaris, are strengthened because they play a role in preventing a specific disorder of the wrist, known as Volar carpal intercalated instability.
Putting weight on the wrist is permitted after three months of the procedure. This means you can start using your wrist for normal activities like lifting objects.
Once the wrist bones are stable enough, isometric exercises (a type of strength training), strengthening exercises, and weight-bearing wrist exercises are recommended by doctors. These exercises are designed to strengthen your wrist, helping in a faster and more effective recovery
Lastly, exercises and techniques promoting better control of muscles (proprioceptive and neuromuscular stabilization) are fundamental in managing instability in the part of the wrist called the distal radioulnar joint (DRUJ).
Preventing Wrist Instability
Instability in the wrist mostly occurs due to a direct blow, like a fall or some other type of injury. If you’re experiencing ongoing discomfort or any other issues with your wrist after such an incident, it’s a good idea to see a doctor who specializes in hand and wrist injuries. The earlier you get treated, preferably before any long-term changes happen in the small bones of the wrist (known as carpals), the less aggressive the treatment needs to be. Proper treatment, followed by a good rehabilitation program, plays a key role in getting your wrist back to its normal functioning capacity.
