Injuries to the Triangular Fibro-Cartilaginous Complex (TFCC)

What is the TFCC?
The TFCC refers to a number of structures that includes ligaments and cartilage, that connects the ends of the ulna and radius together. It is one of the main stabilisers of the wrist particularly on twisting movements. The TFCC transmits 20% of the forearm’s axial load and acts as a shocker absorber.

What happens to the TFCC with age?
As with all joint structures, they undergo wear and tear as people age. In very young patients, there is a thick layer of cartilage covering the bones of the wrist, and the fibrocartilage of the TFCC is also thick and strong. With age, the cartilage wears down, so that when people hit around 80 years of age, the layer is comparatively thin and has lost much of its strength. In addition, the central part of the fibrocartilage disk often perforates in the middle, resulting from pressure from the underlying ulnar head. It is quite normal for these changes to occur, and most of the time the changes seen do not produce any instability of the wrist.

How is the TFCC injured?
There are two types of injury seen at the TFCC:

TRAUMATIC INJURIES – In a traumatic TFCC injury, there is disruption of the attachments or the substance of the TFCC. The TFCC can be injured in isolation or as part of a generalised wrist injury, such as a fracture of the distal radius. Isolated TFCC injuries often occur from a fall with a significant twist applied to the wrist joint, but may also occur when forcibly twisting the wrist with a high torque, such as a power drill jamming or hitting a golf ball awkwardly. These injuries can be stable or unstable (see treatment below).

DEGENERATIVE INJURIES – These are really mis-named, as they are not injuries, but degenerative conditions that can produce pain from the TFCC.

TRAUMATIC TFCC INJURIES

What are the symptoms of a traumatic TFCC injury?
The most common symptoms of TFCC injury are pain and swelling over the ulnar side of the wrist, and difficulty rotating the forearm. Occasionally, clicking or snapping in the wrist is seen on rotation, and very occasionally the wrist ‘jams’ such that it does not rotate at all.

How is a traumatic TFCC tear diagnosed?
Usually the diagnosis is made provisionally with the clinical history and examination findings. There is a history of injury, with many of the symptoms above noticed. Clinical examination centres on the STABILITY of two joints around the wrist – the distal radio-ulnar joint and the ulna-carpal joint. These joints are stable when the ligaments around the joints are maintaining a normal relationship between the bones, even when a force is applied. They are unstable when the relationship between the bones shifts to an abnormal appearance and this can usually be demonstrated when force is applied to the joint.

Investigation of a TFCC tear involves a plain X-ray. This will show any associated bony injury and can help establish whether the joints are stable or unstable. An MRI is then performed, and this will usually pick up a significant tear or injury to the TFCC. Occasionally, wrist arthroscopy is recommended to assess the injury. We do not offer this procedure in Fife, but if appropriate, we will ask our colleagues in Lothian to undertake this operation.

What is the natural history of a traumatic TFCC tear?
Stable injuries – The vast majority of TFCC tears heal with time. The body uses scar tissue to substitute for torn ligament or fibrocartilage tissue, and this is not quite as strong as normal ligament or fibrocartilage. In addition, the scar tissue is bulky, and takes around 18 months to mature and become reliable. Unfortunately, this makes recovery from a TFCC tear much slower than most people think is reasonable!

With time, however, the wrist pain slowly improves and in most cases eventually settles. The scar tissue that has formed often gives the wrist a slightly different contour on the injured side which can worry people, but is normal after this injury.

Unstable Injuries – Even when unstable initially, the majority of these injuries will heal with time. Problems arise when the abnormal position of the joint is maintained – in this case, even although healing occurs, the normal function of the joint is impaired and can therefore give rise to long term symptoms.

A patient demonstrating instability of the ulnar side of the wrist.

What are the treatment options?
For most stable injuries, the wrist is immobilised in a splint or cast is order to help with pain relief whilst the body heals. The healing process takes around 3 months with this type of injury and it is often 6-12 months before normal function is regained.

In the case of an unstable injury, then the goal of treatment is to convert this into a stable injury in order to allow healing in an anatomical position. This will usually involve surgery, and often require any associated bone injury to also be stabilised. Repairing the TFCC uses very strong sutures or thread which are attached to an anchor – usually made of metal. This anchor is placed in the underlying bone and allows surgeons to reattach the cartilage or ligament to the bone where it has been injured.

What is the outcome following surgery for an unstable TFCC injury?
The outcome is generally good, but few people think that their wrist is normal after this injury. This is usually because rotation of the forearm is limited or because the wrist feels weaker on the injured side. Occasionally, people report very poor results, and this usually represents failure of the repair, or a situation where an unstable injury has been mistaken for a stable injury.

DEGENERATIVE TFCC INJURIES

These are misnamed, because they are not associated with injury, but occur as part of a degenerative process. The triangular fibrocartilage (TFC) is most often involved, and rarely the ligaments. Where the TFC wears, it can become frayed, or detached from its normal bone attachment. This is very common, and often gives no symptoms. In some patients, inflammation is seen around the cartilage, and this generally does give pain.

What are the treatment options?
– Conservative management – Once the diagnosis is made, the most common recommendation is for conservative management. A wrist splint may be useful, and sometimes a tubigrip support bandage helps. Pain will settle with time, but this can be a bit frustrating as it can be up to 2 years before the wrist settles for some patients.
– Painkillers – Although painkillers can be useful where symptoms are interfering with a specific function (eg golf), all painkillers carry a small risk of harm if taken regularly. Few patients report that they are particularly useful, and therefore we do not recommend regular analgesia for this problem.
– Steroid injection – Steroid injections have a powerful anti-inflammatory effect, and can help relieve pain from a degenerative TFC tear. Unfortunately, steroid is not particularly good for the cartilage tissue and the pain relieving effect is often short lived. You can read more about steroid injections here.
– Surgery – Surgery may be an option where there is a clear underlying structural problem giving rise to the pain. This can be a problem with the underlying bone, or a mechanical displacement of the TFC which is jamming the joint. If this is an option, then a full discussion of risks versus benefits with the surgeon is essential before making any final decision.

© Fife Hand Service 2020

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