Total wrist fusion is predominantly performed for severe wrist arthritis. A total wrist fusion stops all movement at the wrist joint, so it is not an operation to undertake lightly. However, it provides welcome relief for patients who are unable to use their hand due to wrist pain and instability.
The severe arthritis that leads patients to a total wrist fusion can be the result of a number of conditions. Sometimes damage to the wrist ligaments as a young adult sets up changes in wrist biomechanics that lead to progressive arthritis. Sometimes rheumatoid arthritis is the underlying cause. There are also other uncommon reasons patients may undergo a wrist fusion – when part of the wrist has to be removed due to cancer or infection, or when there is paralysis of the wrist or hand.
When to have a total wrist fusion
Total wrist fusion may be performed after a (failed) partial wrist fusion, after a (failed) joint replacement or after surgery for major trauma (or tumour) at the wrist. It can be used as a “surgery of last resort”. It can also be used in younger patients who face progressive arthritis and wish to have a single operation and recovery, rather than try a partial fusion.
How will the loss of movement affect me?
Most activities can be performed despite the loss of wrist movement. The most difficult activity is toileting (most people find that they need to hold the toilet paper in their unfused wrist when wiping themselves). Lifting a glass from a low table is problematic, as is picking up coins from a table. If you want to know how the limited range of motion will affect you simply try wearing a splint that holds you in the position that you will be fused in.
What does the surgery involve?
The surgery involves having a metal plate will be placed across the wrist joints, preventing movement. The cartilage surfaces of the wrist bones will be removed, and bone graft placed between the gaps to facilitate bone-to-bone fusion. The bone that is used for grafting is generally taken from the bones around the wrist that is undergoing the fusion. Discuss with your doctor whether excision of the nerves that transmit pain from the wrist would also be suitable for you as part of this operation.
Post operative management
After the surgery you will be immobilised in a cast for 6 weeks. This is necessary to ensure that there is no movement at the fusion site, to maximise the chances of the bones successfully uniting. In the normal post operative course you will begin strengthening exercises at 8 weeks, and be allowed full use at 10 weeks. Your post operative strengthening and recovery will continue for many weeks; many patients report that they are not fully recovered until the 6 month stage and grip strength often continues to improve until the 12 month stage.
Complications may include ongoing pain, non-union (failure of the bones to fuse), plate or screw fracture or loosening, worsening of carpal tunnel syndrome, an unsightly scar and rubbing of tendons on the plate leading to rupture of tendons.