What the TFCC is
The TFCC sits on the little-finger side of the wrist, between the end of the ulna (the forearm bone on that side) and the small wrist bones. It is a disc of tough cartilage (fibrocartilage) plus the ligaments that tie the two forearm bones together and the ulna to the wrist, and the sheath of a tendon. It steadies the distal radioulnar joint (DRUJ), where the forearm bones turn on each other as you turn your palm up and down, and spreads load across the wrist. Soft tissues give about 80% of that joint's stability.
Only the outer 20% or so of the disc has a blood supply. That is why tears at the edge can heal, while tears in the middle mostly can't, though they often stop hurting.
Sources 1, 2
Types of tear, and who gets them
Doctors sort tears into traumatic ones, from a fall on an outstretched hand or a forced twist, and degenerative ones, from wear. Traumatic tears are named by where they are: in the centre of the disc, at its edge on the little-finger side, at the ligaments to the wrist bones, or where it joins the radius. Tears at the edges may be repairable; a central tear can only be trimmed.
Repeated loading with the wrist bent towards the little finger, in racquet sports, golf, weight-bearing on the hands and manual work, raises the strain, as does an ulna that is long compared with the radius. Wear starts early: in a study of 180 wrists from people who had died, holes in the disc were absent before 20 and found in 7.6% of wrists of people in their 20s, rising to 53.1% over 60.
Sources 3, 1, 2, 4
How it's recognised
Pain on the little-finger side of the wrist, worse twisting, gripping or leaning on the hand, sometimes with clicking and a weak grip. A clinician will press a soft spot next to the bony knob on that side (the ulnar fovea). In 272 people who had keyhole wrist surgery, tenderness there picked up 95% of the ligament injuries it looks for and was seldom positive without one, though another study found it far less specific.
X-rays rule out a fracture and show the length of the forearm bones. MRI (magnetic resonance imaging) is the usual scan: in the figures one review cites, it finds about 92% of tears, but it misses some at the edge. Keyhole surgery (arthroscopy) is the most reliable test, and is used when surgery is being considered.
Sources 2, 1, 5
What a scan finding does and doesn't mean
TFCC tears are common in wrists that don't hurt. In 103 volunteers with no wrist symptoms, MRI looked abnormal in 39 wrists, including 23 complete tears, and in all 3 people over 60. In 92 people scanned for other wrist problems, 44% had TFCC changes, against 80% of 40 people who had pain on the little-finger side. A review of 7 studies (501 wrists) found such changes at every age.
So a tear on a scan doesn't prove it is causing your pain. What counts is whether your symptoms, the tender spot and the stability of the joint match it.
Sources 6, 4, 7, 8
Things that look like a TFCC tear
Several problems cause pain in the same place, and their signs overlap, so pain that doesn't settle needs a clinician's check.
- The extensor carpi ulnaris (ECU) tendon on the back of the wrist: pain over the tendon, sometimes with it clicking out of its groove as the palm turns up. Overuse usually settles with a break from the provoking movement, a splint for about 3 weeks, anti-inflammatory medicines and retraining the muscle.
- Ulnar impaction: a long ulna pressing into the wrist bones, usually with wear of the TFCC.
- Other ligament injuries, and arthritis between the small wrist bones on that side.
- The ulnar nerve at the wrist: weakness, clumsiness and numbness in the ring and little fingers.
- The ulnar artery: a blocked artery from repeatedly striking things with the heel of the hand.
- A fracture of the hamate, the tip of the ulna or the end of the radius.
Source 2
How it usually goes
Many tears settle without surgery. In 84 people splinted or in a cast for at least 4 weeks, 57% didn't go on to an operation. In 89 traumatic tears splinted for 6 weeks, 76% did well with a splint that also held the forearm still against 29% with a wrist splint. In 33 people whose forearm joint was stable, non-surgical care and keyhole trimming gave similar results at about 2 years, and a review of 8 studies (425 people) found non-surgical care comparable to surgery.
In one series of children and teenagers with a suspected TFCC injury, non-surgical care worked in 36%, and only with a cast above the elbow, so a young person with ongoing pain needs a hand specialist's assessment.
Sources 9, 10, 11, 12, 13