Osteoarthritis of the wrist (carpus) or ankle (tarsus) often leads to debilitating joint pain and lameness. Similarly fractures of the wrist or ankle often involve the joint, or the ligaments of the joint, and create a number of small fragments. If the injury to the joint or ligaments is severe, then fusion of the joint may be the best long-term option to minimise the risk of complication, ongoing joint pain and the development of severe osteoarthritis. Joint fusion removes the articular cartilage from the joint surfaces, and uses a metal plate to hold the joint at a fixed angle whilst the bone heals at a normal walking angle. Once the bones have fused the implants may be removed, or most stay in position for the life of the patient, unless they cause irritation or develop a late infection. Joint fusion (arthrodesis) are most reliably performed using plates and screws, but other techniques using pins, wires or external fixation may be considered. Joint fusion aims to provide pain relief by immobilising the joint and allowing early return to function and weight bearing.
Complications rates are low, with the most common complications being infection, usually less than 5% depending on the type of the fracture and other injuries sustained at the time. The infections usually only require antibiotics in addition to the ones dispensed at the time of surgery, or in a much smaller number of cases where the implants are infected, removal of the implant via a short simple procedure. Generally, the implants never need to be removed and cause no problems, however a very small number may develop an infection years following the surgery, which will present as a painful limb, limping or discharging wound near the previous surgical site. Occasionally the implants can cause irritation to the soft tissues, causing discomfort and lameness, and may benefit from being removed. Tarsal arthrodesis implants are more commonly removed as they may cause irritation of the long bones of the feet. Should the implants cause discomfort removal is usually an easy procedure requiring a short general anaesthesia.
Other complications are related to either the injuries of the trauma themselves, or those sustained during manipulation of the bones during surgery and reconstruction. Nerve injuries are often difficult to accurately assess immediately following trauma as there may be a period of time required for trauma related shock and inflammation to resolve, and also the limb function will often be severely affected.
The other most common complication is related to the patient themselves, with over activity and excessive stress placed on the healing bone and implants, with either failure and breakage of the implants or bone the implants are anchored to. Generally gentle lead controlled walks in incrementally increasing lengths are well tolerated in the weeks following fracture repair. However, it is the short periods of high risk activity when these avoidable complications occur. Jumping, stairs, slippery floors, any off-lead activity will increase this risk and potentially cause catastrophic failure requiring repeat surgery. As the owner you will be the brains of the recovery and be responsible for enforcing the strict rest and confinement, rehabilitation program, and lead controlled walks, prior to a return to normal activity over a 12-16 week period.
Pancarpal Arthrodesis Discharge Form (PDF)