The triangular fibrocartilage complex (TFC) is a very common source of pain on the ulnar (small finger) side of your wrist. The TFC is the main ligament that stabilizes the distal radio-ulnar joint (DRUJ). The DRUJ is the part of the wrist joint that lies between the two bones of your forearm (the radius and ulna) and allows your forearm to rotate. The TFC also functions as a shock-absorber for your wrist, like a meniscus in the knee.
The TFC may become injured by a fall, sports injury, car crash, or other trauma. TFC tears are especially common with wrist fractures, and are often the main cause of wrist pain after the fractures have healed. Sometimes, the TFC can get worn through over time and tear without any injury if the ulna bone (the forearm bone on the small finger side) is longer than your radius (the forearm bone on the thumb side). This relatively long ulna puts a lot of pressure on the TFC with wrist use.
MRIs are not very accurate in diagnosing TFC injuries, which are better diagnosed based on a good history and physical examination. Nonoperative treatment starts with a splint, a steroid injection, avoiding forceful forearm rotation (like when using tools) and avoiding putting weight on the extended wrist (like when pushing to get up off the floor, out of a pool, pushing a heavy door open, etc). If you weight-lift, you want to use a splint while lifting to avoid keep the wrist from extending. All heavy weight lifting should be done with the wrist in neutral, not extension.
If nonoperative management fails and the TFC tear is still painful, the next step is often a diagnostic arthroscopy. If there’s just a flap of injured tissue causing the problems, but the DRUJ is stable, the flap can be removed arthroscopically. If the TFC is torn, but the DRUJ is stable, the TFC tear can be repaired arthroscopically. If the TFC is torn and the DRUJ is unstable (loose), an open repair is usually the best treatment. The results from these surgeries are usually very good. If a TFC repair is performed, an above-elbow cast will be used for 4 weeks, and then therapy is started.
Often times, the TFC injury is either caused or exacerbated by the ulna being longer than the radius. In these cases, the ulna may have to be shortened to prevent the TFC from re-tearing. The ulnar shortening can be performed at the same time as the TFC repair. Sometimes, if the relative ulnar length is not too bad, a TFC repair is done without ulnar shortening. In these cases, if pain persists the ulnar shortening is then performed as a 2nd surgery.
Ulnar shortenings are traditionally done through a long incision: A small length of bone (usually 2-4 mm) is removed from the middle of the ulna and a plate is put on to stabilize the ulna while it heals. A short-arm cast is worn for 6 weeks and heavy activities are avoided until the bone is healed, which can take 3-4 months. However, a newer technique of ulnar shortening can be performed through a smaller incision, with a quicker healing time. In these cases, after 2 weeks only a removable splint is used. The newer type of ulnar shortening usually heals in 6 weeks. Most, but not all, patients will have this newer option available to them.
In summary, TFC tears are very common. Fortunately, there is effective treatment for them. All of the surgeries discussed here are performed as outpatient procedures (you go home the same day), and newer techniques are available that allow patients to return to activities quicker, with fewer problems.