In outpatient clinics, we often encounter patients who have wrist pain. After applying creams, topical safflower oil and fotarine, the pain is relieved, but the swelling and pain start again when they move. Most of the time, this is due to damage to the triangular cartilage complex of the wrist.
The triangular fibrocartilagecomplex (TFCC) is a group of important structures on the ulnar side of the wrist, including the articular disc, meniscal homologue, palmar and dorsal distal ulnar radial ligaments, deep ulnar extensor tendon sheath, ulnar capsule, ulnar ligament, and ulnar deltoid ligament. The palmar and dorsal distal ulnar radial ligaments include superficial and deep fibers and converge at the radial attachment. The complex anatomy and multiple functions of the TFCC make it susceptible to trauma and degeneration.
Because the TFCC structure is deeply embedded in the small space of the ulnar wrist joint, the pain and swelling symptoms at the time of injury are not always obvious, and patients usually mistake it for a common wrist sprain, which often delays consultation and treatment of the injury. Injuries such as fractures of the distal radius are often combined with injuries from falling hands on the ground, and injuries from TFCC are also easily overlooked or missed at the initial visit.
Common causes of TFCC injuries.
(1) Fall with the palm of the hand on the ground;
(2) ulnar side force and rapid twisting activities of the wrist in tennis, golf, badminton, etc;
(3) Rotational distraction violence on the wrist of the driver holding the steering wheel in a car accident;
(4) violence to the wrist in the process of sparring with people;
(5) Sprain from inadvertent lifting of heavy objects or improper wrist force.
Diagnosis.
Acute TFCC injuries are usually combined with ulnar swelling of the wrist joint. The sensitivity and specificity of pressure pain at the ulnar head recess for the diagnosis of ulnar head recess discontinuity and/or ulnar deltoid ligament tear are 95% and 86%, respectively. the TFCC crush test may be positive, i.e., pain with axial stress applied during wrist ulnar deviation. The stability of the distal ulnar radial joint is examined in the anterior and posterior forearm rotation positions, and the ulnar head is examined for a positive piano key sign.
If combined with a tear of the lunotriquetral ligament, this may be accompanied by local pressure pain of the injury and a positive lunotriquetral shear test. Stabilization of the radius and passive movement of the ulna, if there is an increase in anterior-posterior slip relative to the radial ulna, indicates instability of the distal ulnar radial joint (DRUJ). Because the slip of the joint varies with forearm position and among individuals, the examination should be performed in all positions of the forearm and should be compared with the contralateral side.
Imaging. Although X-rays do not directly show soft tissue lesions, certain indirect information can be obtained, such as ulnar varus, the condition of the inferior ulnar radial joint and the presence of ulnar styloid or distal radius fractures. If cystic degeneration exists in the lunate and distal ulna, and when combined with ulna with or without positive degeneration, it indirectly proves that the ulnar side of the carpal bone is overstressed, and methods of weight reduction should be considered during treatment.
Magnetic resonance imaging (MRI) has become the primary means of diagnosing TFCC. If the injury is degenerative and combined with ulnar impingement syndrome, MRI can show edema on the ulnar side of the lunate bone.
Wrist arthroscopy is the gold standard and the best method for diagnosing TFCC injuries.
Treatment.
There are many options for treating TFCC injuries, and the type of treatment needed depends on the following factors: the presence of wrist pain (including mechanical irritation from the injury or persistent joint pain from synovitis), the presence of an associated fracture or fracture malunion, and the presence of distal ulnar radial instability. If the patient’s history and examination are suggestive of a TFCC injury, but the x-ray is normal, the patient may be immobilized with a long-arm cast or brace for 4-6 weeks in the acute phase.
If there is no relief of symptoms after immobilization, further investigations, such as MRI and arthroscopy, are required. TFCC injuries that have failed to respond to 2-3 months of conservative treatment have indications for arthroscopic surgery.
Acute TFCC injuries (less than three months before repair) have a better prognosis than subacute (three months to one year) and chronic injuries (more than one year), as they can sometimes be repaired directly, but usually with reduced strength. Rarely chronic injuries can also be repaired, but often unsatisfactorily compared to acute injuries, for reasons presumably related to ligamentous strain and degeneration of the fibrocartilage rim.
Therefore, for chronic injuries, ulnar shortening and/or TFCC debridement is usually required, and in some patients, reconstruction of the distal ulnar radial ligament is required if combined with symptomatic chronic distal ulnar radial instability .
Rehabilitation
If only arthroscopic TFCC debridement is performed, postoperative braking is generally not required. If arthroscopic TFCC repair is performed, postoperative braking with a neutral supra-elbow brace is required for 4-6 weeks. after 6 weeks, gradual passive joint mobility exercises and gentle active strength training are started, and daily activities are gradually resumed after about 10-12 weeks, and sports activities are generally resumed gradually after 6 months.