Triangular fibrocartilage complex (TFCC) injuries of the wrist affect the ulnar (little finger) side of the wrist. Mild injuries of the TFCC may be referred to as a wrist sprain. As the name suggests, the soft tissues of the wrist are complex. They 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.
This guide will help you understand
- what parts if the wrist are involved
- how these injuries occur
- how doctors diagnose the condition
- what treatment options are available
What parts of the wrist are involved?
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 triangular fibrocartilage complex (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).
The entire triangular fibrocartilage complex (TFCC) sits between the ulna and two carpal bones (the lunate and the triquetrum). The TFCC inserts into the lunate and triquetrum via the ulnolunate and ulnotriquetral ligaments. It stabilizes the distal radioulnar joint while improving the range of motion and gliding action within the wrist.
There is a small cartilage pad called the articular disc in the center of the complex that cushions this part of the wrist joint. Other parts of the complex include the dorsal radioulnar ligament, the volar radioulnar ligament, the meniscus homologue (ulnocarpal meniscus), the ulnar collateral ligament, the subsheath of the extensor carpi ulnaris, and the ulnolunate and ulnotriquetral ligaments.
Injury to the triangular fibrocartilage complex involves tears of the fibrocartilage articular disc and meniscal homologue. The homologue refers to the piece of tissue that connects the disc to the triquetrum bone in the wrist. The homologue acts like a sling or leash between these two structures.
The triangular fibrocartilage complex 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.
Power drill injuries can also cause triangular fibrocartilage complex rupture when the drill binds and the wrist rotates instead of the drill bit. Triangular fibrocartilage complex (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.
Wrist pain along the ulnar side is the main symptom. Some patients report diffuse pain. This means the pain is throughout the entire wrist area and 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 at the distal end of the ulna bone (at 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.
Your chirorpactor 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 hypersupination (overly rotating the forearm in a palm-up position) and loading the wrist in a position of ulnar deviation (moving hand away from the thumb) and wrist extension.
If an accurate diagnosis can not be made, you may be referred to your medical doctor for additional imaging, including and MRI or arthrography.
If the wrist is still stable, then conservative (nonoperative) care is advised. You may be given a temporary splint to wear for four to six weeks. The splint will immobilize (hold still) your wrist and allow scar tissue to help heal it. Anti-inflammatory drugs and physical therapy may be prescribed.
If the wrist is unstable but you don’t want surgery, then the surgeon may put a cast on your wrist and forearm. It may be possible to use a splint for six weeks (instead of casting) and then start active rehabilitation. Your doctor will help you decide what would be best for your particular injury.
Surgical treatment is based on the specific injury present. Instability as a result of complete ligamentous ruptures, especially with bone fracture, requires surgery as soon as possible.
If you suspect you may be suffering from TFCC please contact our offices for a thorough examination and to discuss treatment options!