On the little finger or ulnar side of the wrist joint there is a small triangular shaped piece of cartilage called the triangular fibrocartilage complex. See figure 1. it occupies the space on the x-ray in figure 2 marked by the arrow. the TFCC performs several important functions. It acts as a shock absorber on the ulnar side of the wrist and helps to spread out pressure more evenly on that side of the joint. It also helps to hold the radius and ulnar together, stabilizing the distal radial ulnar joint, or joint where the radius and ulna rotate around each other to allow your hands to rotate (pronate and supinate). a volar radial ulnar ligaments and dorsal radial ulnar ligament are incorporated in both sides of the TFCC and help hold the two bones together. An ulnar collateral ligament that holds the ulnar side of the wrist together attaches to the TFCC. Finally a sheath that holds one of the wrist extensor tendons(ECU) attaches to the TFCC. Because of its many functions the TFCC is small but important.
The TFCC may be damaged by both injury and attrition. By repetitive wrist wrist motion and forearm rotation, the central portion of the TFCC may become thinned or degenerate. Some research papers estimate that 50% of people over the age of 50 have some degeneration of the central portion of the TFCC. This may produce symptoms were not. a TFCC tear may also be produced by a fall or sudden twist (pronation or supination) of the wrist such as the patient who tries to catch something or have the wrist twisted by a drill when the drill bit catches. they may notice a sudden pop at the time of injury. Symptoms of a torn TFCC are pain/swelling on the ulnar side of the wrist. There may be pain with ulnar deviation of the wrist(moving the wrist towards the little finger). there also may be pain and popping or clicking with extremes of pronation or supination of the wrist and forearm.
Evaluation of a TFCC injury includes careful physical examination to look for swelling and tenderness. There are multiple anatomical structures that can cause ulnar sided wrist pain. There should be tenderness directly over the TFCC. Extremes of pronation and supination may cause discomfort or clicking. Moving or balloting the distal radius and ulna back and forth may produce discomfort. X-rays may be taken to evaluate a possible ulnar fracture that sometimes accompanies a TFCC tear. usually an MRI with or without introduction of dye into the joint(arthrogram) is the gold standard for evaluating a possible TFCC tear. Some small partial tears can still not be visualized by the MRI and may only be detected by arthroscopy, or looking in the joint with a small scope.
Treatment of acute or recent TFCC tears associated with a nondisplaced styloid fracture of the ulna may be treated conservatively with a long-arm splint or cast for 6 weeks. Good results may be achieved if the ulnar styloid fracture heals with the attached TFCC. Most TFCC injuries do not involve a fracture and are strictly soft tissue. These are usually addressed by arthroscopic debridement. In this surgery two small incisions or portals are made at the wrist. one portal is used to introduce the small scope in order to visualize her see the joint. The other portal is used to introduce a small shaver or other tools. Most TFCC tears are in the central portion and it will not heal due to very poor blood supply of the cartilage. The tear is simply trim back to a stable rim using the shaver. Occasionally the TFCC tear will occur out on the periphery where blood supply is better. These tears may be prepared, either through the arthroscope or through a small incision. The surgery is usually performed as an outpatient with general anesthesia or an axillary block, numbing the arm. After debridement or trimming of the TFCC, a simple dressing is applied and gentle active range of motion is permitted. After a TFCC repair a long-arm splint or cast is applied since the repair must be protected for 6 weeks. Risks with these procedures include anesthesia related risks, wound healing problems or infection and continued irritation or arthritis of the wrist.In some cases of TFCC injury the ulna may be longer than average and impact or rub against the ulnar side of the wrist joint, causing or aggravated by, the TFCC tear. This is called ulnar impaction syndrome. If the above treatment does not help, the ulna may need to be shortened by either arthroscopic or open methods.