Ligament and TFCC injuries (instability) of the wrist
What is it?
The wrist is one of the most complex joints in the body. It consists of 8 carpal bones arranged in two rows. These bones articulate with one another and the two-forearm bones - the radius on the thumb side and the ulna on the little finger side. All the bones and the joints they form, are stabilized by a number of ligaments. The ligaments also control the movements of the bones with one another. In addition there is also a joint between the radius and ulna (the distal radio-ulnar joint). This joint is connected to the wrist by a complex of ligaments, tendon and a cartilage disc. The complex that stabilizes the wrist at the distal radioulnar joint is known at the ‘triangular fibrocartilage complex’ (TFCC). It also bears most of the forces that go through the wrist.
What is its cause?
The wrist ligaments and the TFCC can be injured in various ways. The most common way the wrist becomes injured is through impact via a fall. Injuries can also occur due to other direct impact or forceful twisting or overuse (racquet sports, gymnastics). Once the ligaments are disrupted, the bones will collapse under load causing symptoms. TFCC injuries are the most common soft tissue injuries of the wrist. The other ligaments that become commonly injured are the ligaments between the scaphoid and the lunate; and between the lunate and triquetrum.
What are the symptoms and how is the condition diagnosed?
The symptoms of wrist instability will range from pain after gripping, to clicking or popping within the wrist. With TFCC injuries, the pain will be mainly on the little finger side of the wrist and made worse by movement of the wrist in the direction of the little finger or when the forearm is rotated. The clinical diagnosis is made by noting the area of tenderness and performing special provocative tests.
Will further tests or investigations be needed?
After appropriate clinical assessment, a set of x-rays will usually be recommended. If a ligament between two bones is torn, the gap between the bones increases (x-ray below) and the bones will not be normally aligned.
Sometimes x-rays will not show subtle ligament injuries and therefore further investigation will be needed by an MR arthrogram. A dye is injected and a magnetic field is used to create cross sectional images.
What is the treatment?
- Physiotherapy and splintage is the initial method of treatment. Activities that aggravate the symptoms should be avoided.
- If the symptoms persist, surgery has to be considered.
Arthroscopic (keyhole) wrist surgery for TFCC injuries: About 2-3 small incisions of 5mm each are needed. A telescope is passed into the wrist through one of these incisions and special surgical instruments are passed through the other incisions. Recent injuries to the TFCC complex can be confirmed and repaired arthroscopically. Simple tears of the cartilage will be debrided. The advantage of keyhole surgery is that it is less traumatic and so recovery is quicker. It is usually carried out as a day procedure.
Arthroscopic (keyhole) surgery for wrist instability: About 2-3 small incisions of 5mm each are needed. A telescope is passed into the wrist through one of these incisions and special surgical instruments are passed through the other incisions. The aim of arthroscopy in wrist instability, is to confirm the ligament injury and assess the instability.
Open surgery for TFCC tears: It is not possible to repair old, degenerative tears. A surgical procedure that will shorten the ulna, and reduce load on the little finger side of the wrist, is used to reduce pain in such circumstances.
Open surgery for wrist instability: With this type of surgery, the torn ligaments are reconstructed by using a part of a tendon. This is because acute repair of the ligaments is usually not possible. Different procedures are described for various ligament injuries and you will need to discuss this with your specialist, as treatment of such injuries is complex.
What happens if it is not treated?
If the above conditions are not treated it is likely that the symptoms will persist. It may be that the wrist may become less troublesome if activities that cause the problems are stopped. It is possible that an unstable wrist may cause arthritis in the long term (need link to wrist arthritis page here). This depends on the nature of the original injury and extent of instability.
What is the success of surgical treatment?
Surgical treatment for TFCC injuries results in a good success rate. The injuries that cause wrist instability can also be treated successfully, but since the instability is due to a spectrum of injuries, success rate for individual injuries and their surgery will vary.
What are the complications of surgical treatment?
- Infection of the wound is possible and can usually be successfully treated with antibiotics.
- Loss of movement is possible especially after open surgery.
- Damage to the nerve or blood vessels is possible.
- The operation may fail to relieve the symptoms.
- Any surgical intervention has the risk of developing complications that are unpredicted. These complications may have the potential to leave the patient worse than before surgery.
Is there anything I can do to improve the outcome?
Keep the wounds dry and clean until they have healed.
It is important to remember that at operation ligaments are reconstructed. The wrist will be protected in a splint that extends to the elbow after the operation. The physiotherapist will supervise rehabilitation of the wrist after the operation. It is very important that the instructions are followed.
When can I do various activities?
Return to work depends on many factors including the nature of the job and hand dominance. Generally, patients return to a desk job within 4-6 weeks of the operation and perform reasonable tasks with the limb within 6-8 weeks. You will be unable to drive for a period of 6-8 weeks and activities like golf; racquet sports are best avoided for at least 3-4 months. These recommendations will vary from patient to patient.