Finding the Right PatientAnkle fusion surgery is a good option for patients with severe arthritis of the joint, and can be performed in patients of all ages. When compared to ankle replacement surgery, ankle fusion is often preferred in more active patients, who may wear out the ankle replacement.
Ankle fusion surgery is not a good treatment for patients who can manage their symptoms with simpler, non-surgical treatments: patients who have ankle fusion will have a permanently stiff joint, and may be unable to perform certain activities such as running. In addition, ankle fusion should be performed cautiously in patients who've had infections in the joint, or in patients who are smokers, as these patients have a high risk of developing complications from surgery.
Performing an Ankle FusionThere are many surgical techniques for performing an ankle fusion, but all of these procedures accomplish the same goal of permanently fusing the ankle joint so it can no longer bend. The first step is to remove any remaining cartilage and create a level bone surface on the top and bottom of the ankle joint; the next step is to align the bones in the proper position for the fusion. Finally, metal implants — usually large screws — are used to hold the bones in this position.
The procedure may be performed several different ways, depending on factors such as the amount of deformity of the joint, the extent of the arthritis, and surgeon preference. Some surgeons use ankle arthroscopy to remove the cartilage, while others make a larger incision and look directly at the joint.
Interestingly, the metal hardware that is placed to hold the bones is not needed once the fusion of bone has occurred: the metal is used to hold the joint in place while the fusion heals, but once bone has grown across the joint, the metal is no longer necessary. In some cases, patients can feel the metal screws, so they may be removed. But there's no need to remove the screws if they're not causing a problem.
Recovery From SurgeryAnkle fusion surgery is usually followed by a one-night stay in the hospital to ensure pain is managed, and the patient is comfortable. Patients are placed in a cast and will remain off of the affected ankle by using crutches or a walker. This allows new bone to heal across the fused joint, and once the bone starts to fuse, patients can begin to place weight on the joint. Typically people will have to stay off of the ankle for 8-12 weeks, followed by protected walking in a boot or cast. Complete healing of an ankle fusion may take 4-6 months.
Complications of Ankle FusionThe most significant concern after an ankle fusion surgery is called a nonunion, which occurs when the bones that are being fused do not heal together. There are factors that tend to lead to nonunion, but even in the ideal patient, nonunion can occur. Patients who are smokers have a much higher rate of nonunion, and should carefully consider the risk of this possible complication. Smoking cessation can be helpful in lowering the chance of a nonunion.
Other problems associated with ankle fusion surgery include infection, wound healing problems, and arthritic changes in the small joints of the foot. Because ankle fusion limits motion, patients often develop arthritis in the joints of the foot down the road. Furthermore, patients who undergo ankle fusion surgery may need to get their shoes modified to aid in walking for the rest of their lives.
Abidi, NA, et al. "Ankle Arthrodesis: Indications and Techniques" J. Am. Acad. Ortho. Surg., May/June 2000; 8: 200 - 209.