Finger fusion

Mr Mike Hayton
FRCS(Trauma and Orth) FFSEM (UK)
Consultant Orthopaedic Hand Surgeon

A joint fusion is an operation that involves removing the damaged ends of the joint and compressing them together until the bone has grown across the joint.

Finger fusions are often performed for osteoarthritis. The most common joint to be fused is the distal interphalangeal joint (DIP joint). This is the end finger joint, just behind the nail.

Who does it affect?

Finger arthritis usually occurs in patients over 40 years of age.

Why does it occur?

The articular cartilage, which is the slippery lining of the surface, has been worn away, and the exposed bones rub against each other, causing pain. Therefore a small joint fusion, such as this, is very successful at reducing this pain. There are very few functional limitations as a consequence of fusing the DIP joint.

Symptoms

Patients often present with a painful, lumpy joint and a decreased range of movement.

Clinical examination

Finger arthritis usually has a stiff swollen joint, often with knobbly bumps.

Operative treatment

The surgery usually takes place under local anaesthetic, under x-ray control. An incision is made on the back of the joint. The tendons are divided and the underlying bone prepared so that the two ends of the bone are freshened and come into close contact. These are then held with a variety of fixation devices, most commonly stainless steel wires. The wires are kept in place until the bone has united, usually somewhere between four and eight weeks.

Fixation

There are a number of different methods of fixation of the DIP joint and these include exposed wires, buried wires under the skin, internal screw fixation. The results of each type of surgery are very similar, and generally speaking a 90% chance of the bones healing across can be expected. Here is an x-ray on a patient whose DIP joint was compressed with a headless screw.

Post-operative rehabilitation

If the wires are exposed these need protecting whilst in place. If the wires are buried patients can often return to activities relatively quickly.

Return to activities of daily living

Once the bone has grown across the joint, a rapid return to function can be expected.

Complications

The main risk is the bones not growing together. This occurs in approximately 10% of cases. Other risks are infection and damage to the nail.