Triangular fibrocartilage complex (TFCC) injuries of the wrist affect the little finger side of the wrist. Mild injuries of the triangular fibrocartilage complex may be referred to as a wrist sprain. The soft tissues work together to stabilize the very mobile wrist joint. Disruption of this area through injury or degeneration can cause more than just a wrist sprain. A TFCC injury can be a very disabling wrist condition.
Anatomy
How does the wrist joint work?
The wrist is actually a collection of many bones and joints. It is probably the most complex of all the joints in the body. There are 15 bones that form connections from the end of the forearm to the hand. The wrist itself contains eight small bones, called carpal bones. These bones are grouped in two rows across the wrist. The proximal row is where the wrist creases when you bend it. The second row of carpal bones, called the distal row, meets the proximal row a little further toward the fingers.
The proximal row of carpal bones connects the two bones of the forearm, the radius and the ulna, to the bones of the hand. On the ulnar side of the wrist, the end of the ulna bone of the forearm moves with two carpal bones, the lunate and the triquetrum.
The TFCC suspends the ends of the radius and ulna bones over the wrist. It is triangular in shape and made up of several ligaments and cartilage. The TFCC makes it possible for the wrist to move in six different directions (bending, straightening, twisting, side-to-side).
There is a small cartilage pad called the articular disc in the center of the complex that cushions this part of the wrist joint.
Causes
Why do I have this condition?
The triangular fibrocartilage complex (TFCC) stabilizes the wrist at the distal radioulnar joint. It also acts as a focal point for force transmitted across the wrist to the ulnar side. Traumatic injury or a fall onto an outstretched hand is the most common mechanism of injury. The hand is usually in a pronated or palm down position. Tearing or rupture of the TFCC occurs when there is enough force through the ulnar side of the hyperextended wrist to overcome the tensile strength of this structure.
High-demand athletes such as tennis players or gymnasts (including children and teens) are at greatest risk for TFCC injuries. TFCC injuries in children and adolescents occur more often after an ulnar styloid fracture that doesn’t heal. Power drill injuries can also cause triangular fibrocartilage complex rupture when the drill binds and the wrist rotates instead of the drill bit.TFCC tears can also occur with degenerative changes. Repetitive pronation (palm down position) and gripping with load or force through the wrist are risk factors for tissue degeneration. Degenerative changes in the TFCC structure also increase in frequency and severity as we get older. Thinning soft tissue structures can result in a TFCC tear with minor force or minimal trauma.
Symptoms
What does this condition feel like?
- Wrist pain along the ulnar (little finger) side is the main symptom. Some patients report diffuse This means the pain is throughout the entire wrist area. It can’t be pinpointed to one area.
- The pain is made worse by any activity or position that requires forearm rotation and movement in the ulnar direction. This includes simple activities like turning a doorknob or key in the door, using a can opener, or lifting a heavy pan or gallon of milk with one hand.
- Other symptoms include swelling; clicking, snapping, or crackling called crepitus; and weakness. Some patients report a feeling of instability – like the wrist is going to give out on them. You may feel as if something is catching inside the joint. There is usually tenderness along the ulnar side of the wrist.
- If a fracture of the wrist is present along with soft tissue instability, then forearm rotation may be limited. The direction of limitation (palm up or palm down) depends on which direction the ulna dislocates.
Diagnosis
How do we identify the problem?
The Osteopath relies on the history (how, when, and what happened), symptoms, and physical examination to make the diagnosis. Tests of joint stability can be conducted. Special tests such as stress testing of the wrist radioulnar and ulnocarpal joints help define specific areas of injury.
An accurate diagnosis and grading of the injury (degree of severity) is important. Usually, the grade is based on how much disruption of the ligament has occurred (minimal, partial, or complete tear). There are two basic grades of triangular fibrocartilage complex injuries. Class 1 is for traumatic injuries. Class 2 is used to label or describe degenerative conditions.
Other tests may be done to provoke the symptoms and test for excess movement. These include overly rotating the forearm in a palm-up position and loading the wrist in a position where the hand is moving away from the thumb.
A new test called the fovea sign applies external pressure to the area of the fovea. The examiner compares the involved wrist with the wrist on the other side. Tenderness and pain during this test is a sign that there is a split- tear injury (down the middle length-wise).
Split tears are more common with lower energy, repetitive torque injuries such as bowling or golf.
Treatment
What treatment options are available?
- Soft tissue and special joint mobilisation techniques of the joints helps to restore their range of motion, reduce inflammation and pain.
- Strengthening exercises for the arm and hand help steady the hand and protect the wrist joint from shock and stress. Strengthening improves joint stability and prevents deformity and/or dislocation.
- Acupuncture to encourage healing.
