Partial wrist fusion is performed for painful, arthritis in the wrist. Partial wrist fusion allows some of the wrist movement to be preserved, where a full wrist fusion prevents all wrist movements.
There are many different types of partial wrist fusions, which is not surprising when you consider that the large number of bones involved in the wrist joint (namely the radius, scaphoid, lunate, triquetrum, trapezium, trapezoid, capitate, hamate bones).
The pattern of arthritis and degenerative change in your wrist will determine whether you are suitable for a partial wrist fusion and which bones should be fused.
Broadly speaking, joints that are very arthritic need to be fused (or removed) and joints that are healthy can be left intact.
The upside of wrist fusions is the preservation of movement.
The downsides of a partial wrist fusion are:
- A prolonged recovery is involved, with at least 6 weeks in a cast, and 6-12 months before you are cleared for heavy lifting and contact sports
- The bones may fail to fuse. This is termed “non-union”, because the bones fail to unite. The likelihood of non-union varies between the different types of fusions, but is 10-30%. The risk of non-union is higher in smokers and in patients who fail to adhere to the post operative period of immobilisation.
- Incomplete relief of pain, because there is still some movement in the wrist
- A partial wrist fusion alters the wrist biomechanics, increasing the load on the remaining joints and increasing the risk of arthritis in the wrist joints that were not previously affected. If this occurs your wrist will become painful once more, and if your symptoms are severe a total wrist fusion may then be recommended.
To fuse bones it is necessary to remove the cartilage and joint space between the bones, so a surgical incision is required to gain access to the bones. Usually bone graft will be used to increase the fusion rate. This bone is commonly taken from the wrist that is being operated on, but occasionally a graft from the hip bone (iliac crest bone graft) is used.