Fusion of Arthritic Joints
Fusion (arthrodesis) is an operation performed to remove the cartilage from the joint surfaces and bones are fixed together using metalwork (screws, plate or a combination). The body then heals it like a fracture and new bone grows across the joint to complete the fusion.
Why do I need a fusion?
Fusion surgery is performed to treat the symptoms of a severely arthritic (worn out) joint to alleviate pain and improve function. It is considered when nonsurgical methods of controlling the pain fail. The fusion makes the joint completely stiff and you lose the movements in it, however the neighbouring joints continue to move and try to compensate for the absent movements in the fused joint.
The affected joint is exposed by an incision directly over that joint and the worn out surfaces are prepared by removing all the remaining cartilage. The bones are then fixed with screws or a plate or a combination. Bone graft is also used which is taken from local bone chips, or synthetic material to help in appropriate healing. The operation is performed either under a general or a spinal anaesthetic (the options discussed by the anaesthetic in detail prior to surgery) depending on your medical fitness and mutual preference.
Regional local anaesthetic in the nerves of the lower part of the leg is also often used to help in maintaining appropriate pain relief after surgery. The wound is closed with removable (removed in two weeks after surgery) or absorbable sutures depending on surgeon’s preference. You will have a temporary half plaster of Paris slab behind your lower leg. Depending on the number of joints operated on, the procedure may be performed as a day-case or you may have to stay in the hospital for one night depending on your pain and mobility assessment by the physiotherapists. You will use a walking frame or a pair of crutches with only toe-touch weight bearing on the operated leg for a period of 6 weeks.
After going home, elevation of the ankle and pain killer medications are recommended in the first few days. You are likely to be given heparin injections (depending on surgeon’s preference) for 6 weeks to minimise the risk of blood clots. Wound dressings are not disturbed until you are seen in clinic at 3 weeks stage. At that stage, the ankle is placed in a walker boot and weight bearing is increased gradually. At 6 weeks you will be reviewed in the clinic for x-rays and will continue to mobilise with the boot until the healing is complete (3-4 months). A good level of recovery may take 3-6 months and in some cases even longer depending on the progress of the healing.
What complications can occur after surgery?
Potential risks and complications include infection, wound problems, bleeding, blood clots in the leg or lungs (deep vein thrombosis, pulmonary embolism), non-healing, delayed healing, ongoing pain, stiffness, damage to nerves and vessels, numbness around the scar, chronic regional pain syndrome, metal work problems requiring further surgery, wear and tear in the adjacent joints in the long-term and anaesthetic risks. These potential problems occur in a small percentage of cases but the risk increases with the presence of certain medical conditions and the use of certain long-term medications.