Ulnar Wrist Pain: Triangulofibrocartilage Complex
Injuries to the trianulofibrocartilage complex (TFCC) may be degenerative and develop over time or traumatic and develop more acutely. The TFCC is a shock absorbing structure in the wrist similar to the meniscus in the knee. A good history regarding the location and onset of symptoms and a thorough physical examination are instrumental in clarifying the diagnosis.
Pain along the fifth finger or ulnar side of the wrist, which occurs when the wrist is moved away from the palm, such as when you push yourself up from a chair or during twisting activities, such as opening a jar or a door, is often present. There may not be any swelling or bruising. The frequency and intensity of symptoms may vary, causing the patient to delay seeking orthopaedic evaluation and treatment.
Examination of the wrist will confirm tenderness along the ulnar side of the wrist made worse with passive wrist extension and deviation towards that side of the wrist. X-rays will usually not show abnormalities, but comparing the length of the forearm bones—the ulna and radius—to each other may provide a clue to the nature of the problem. When the ulna is longer than the radius, known as ulnar positive variance, the TFCC is subjected to increased loads and risk of injury.
Initial treatment involves relative rest with a short arm splint or cast and anti-inflammatory medications. If symptoms do not respond to conservative measures, additional imaging is usually ordered. A magnetic resonance imaging (MRI) scan can show the soft tissues and structural changes to the TFCC to make the diagnosis. In order to better see the TFCC, dye may be injected into the wrist to enhance the ability of the MRI to visualize injuries or abnormalities of the TFCC.
With degenerative conditions, the TFCC slowly wears until a perforation develops in the central portion where the blood supply is the poorest and does not allow for healing. This tearing is treated with arthroscopy to debride or remove the damaged tissue. If the ulna is longer than the radius, it will need to be shaved down and shortened. If the condition exists for a long enough period of time, the forces may also damage the ligaments of the wrist and a shortening of the ulna by removing a sliver of bone and repairing the bone with a plate and screws like a fracture can help stabilize the associated ligament injury.
Traumatic injuries may involve different areas of the TFCC. The location of the tear will determine the appropriate treatment. Areas with good blood supply, along the back or dorsal side of the wrist, can heal if the TFCC is repaired. Tears that involve the central portion of the TFCC are treated with removal of the torn tissue in a fashion similar to degenerative tears.
Hand or occupational therapy is usually required during the recovery period after surgery to regain motion and strength to return the wrist to a healthy state.