The Triangular Fibrocartilage Complex (TFCC) is a soft tissue structure in the wrist. When injured, it is a frequent cause of pain on the pinky-finger side of the wrist, known as the ulnar side. An injury, often called a TFCC tear, can range from a mild sprain to a significant tear or rupture of the supporting structures. Because the wrist is highly mobile and used in nearly all daily activities, disruption of the TFCC can be a particularly disabling condition.
The Triangular Fibrocartilage Complex: Anatomy and Function
The TFCC is a set of cartilage, ligaments, and tendons connecting the ulna and the radius to the small bones of the wrist. Located on the ulnar side, its primary purpose is to stabilize the distal radioulnar joint (DRUJ). The structure acts as a shock absorber, distributing loads across the wrist joint, similar to the meniscus in the knee. It also maintains stability during rotational movements of the forearm, such as turning a doorknob. Without an intact TFCC, the ulna would bear significantly greater force, potentially leading to instability and long-term degeneration.
Mechanisms of TFCC Injury
Injuries to the TFCC are categorized into two main groups: traumatic (Type 1) and degenerative (Type 2). Traumatic tears commonly occur from a fall onto an outstretched hand (FOOSH), especially when the wrist is hyperextended and pronated, or from a sudden, forceful twist or blow to the ulnar side. Degenerative tears happen over time due to chronic wear, repetitive stress, or conditions like ulnar positive variance. Ulnar positive variance occurs when the ulna bone is slightly longer than the radius, leading to chronic impaction and thinning of the TFCC. Athletes in high-demand rotational sports like tennis or gymnastics are often at risk for both acute and chronic tears.
Symptoms and Clinical Presentation
The hallmark symptom of a TFCC injury is persistent pain localized to the ulnar side of the wrist. This pain is intensified by activities involving gripping, twisting, or bearing weight on the hand, such as pushing off a chair or opening a jar. The quality of the pain can vary from a deep, dull ache to a sharp, catching sensation during movement. Patients frequently report mechanical symptoms like clicking, popping, or a grinding noise (crepitus) when rotating the wrist. A feeling of instability or the sensation that the wrist is going to “give way” is also common, and swelling may be present in acute traumatic cases.
Diagnosis Confirmation
Diagnosis begins with a detailed history and physical examination, including specific stress tests. These tests manipulate the wrist into positions of ulnar deviation and rotation to provoke symptoms, such as the TFCC compression test or the fovea sign. Tenderness at the fovea, a specific spot on the ulna, is a strong indicator of a TFCC tear. Imaging starts with X-rays to check for fractures or assess for ulnar positive variance. Magnetic Resonance Imaging (MRI) is the best non-invasive tool for visualizing the complex structure and confirming a tear, though arthroscopy is considered the diagnostic gold standard if the diagnosis remains unclear.
Treatment and Rehabilitation
Initial management for many TFCC injuries is non-operative, focusing on reducing inflammation and allowing the tissue to heal. This conservative approach includes rest, often requiring the wrist to be immobilized with a splint or brace for several weeks. Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to alleviate pain and reduce swelling, and if symptoms persist, a corticosteroid injection may be administered into the joint. Surgery is typically reserved for severe tears, chronic instability, or cases where non-operative treatments have failed after three to six months. Operative treatment usually involves arthroscopic surgery to either repair the torn TFCC tissue or debride the damaged fragments, followed by rehabilitation emphasizing strengthening the muscles to improve grip strength, stability, and range of motion.