Triangular Fibrocartilage Disc
The triangular fibrocartilage complex (TFCC) is located between the head of the ulna and the ulnar carpal bones and is comprised of a central segment, the disc (Triangular Fibrocartilage Disc) and a peripheral segment, the radioulnar ligament. The disc acts as a cushion between the carpal bones and the radius and ulna. Its function is similar to that of the meniscus in the knee joint. In most cases, an accident causes a tear of the triangular fibrocartilage complex (TFCC). However, in some cases, it can also be caused by uneven strain onthe wrist, initially causing wear-and-tear and later lesions or injuries and damage to the cartilage disc. Some people have an ulna that is longer than their radius (known as Ulnar Plus Variant). This type of ulnar displacement causes permanently increased pressure to be placed on the triangular fibrocartilage disc which, over time, leads to degeneration or disc perforation.
Examination and Diagnosis
As with all suspicious wrist pain, a careful and accurate diagnosis is the highest priority. A triangular fibrocartilage disc can often be very similar to a sprain and therefore the real cause is not subject to further investigation. Patients commonly report pain and loss of strength during rotational movement in the ulnar side of the wrist. During examination, patients have a positive ulnar grind and Fovea sign clinical test. The patient experiences a trapped nerve sensation in the ulnar region of the wrist. Conventional 2-plane x-ray imaging and a stressed joint x-ray (ball-catcher view) helps rule out other types of injuries. High-resolution magnetic resonance imaging (MRI) provides additional confirmation of the diagnoses while often identifying existing lesions.
In rare cases, a fall onto the wrist with a distal radius fracture can lead to a tear of the stabilising TFCC ligaments or disc. A congenital shortening of the radius compared to the ulna or an ulna-plus variant following shortening as a result of a healed distal radius fracture are further possible causes of wrist pain. Alongside disc repair, an ulnar shortening osteotomy can also be considered for pressure relief.
Conservative therapy following a disc injury rarely leads to long-term treatment success. To begin, splint immobilisation can be used to protect the wrist for a few weeks. The administration of non-steroidal antiphlogistic medication can help relieve the pain. Following this, hand therapy will be necessary.
If the pain does not subside despite conservative therapy, then the option of operative therapy should be discussed. The pain levels usually lead the patient to seek out the advice of a hand surgeon; most patients will already want to undergo surgery to return to a good and pain-free quality of life.. Today, the standard surgical procedure in these cases is a wrist arthroscopy. This is a minimally invasive procedure using a small camera that allows for assessment of all regions of the wrist. Delicate surgical instrumentation is used to perform both the diagnosis and surgical measures For example, for certain types of injuries to the disc, an instrument known as a shaver may be used to flatten the area or the obliterated disc fragments are removed.
If the disc has become detached as the result of an injury, then arthroscopic surgical techniques can be used to reattach the disc to its original and anatomically relevant position.
The procedure is normally carried out on an outpatient basis and takes between 20 and 40 minutes. Plexus anaesthesia or general anaesthesia is used. If approved by the health insurance provider, a one-night inpatient stay is possible.
After the operation, a splint bandage is fitted to the wrist while still in the operating theatre. Finger exercises should begin immediately after the operation. The preoperative pain will gradually subside. The suture material is removed after 12 to 14 days. Regular hand therapy is necessary following the removal of the splint. Generally, full load bearing of the hand can be resumed after 8 to 12 weeks.