Ankle Arthrodesis After Failed Total Ankle Replacement
While ankle fusion has long been considered the standard treatment for ankle arthritis, advancements in total ankle replacement (TAR) are offering new options for patients. TAR procedures have improved over time with better surgical techniques and implant designs, leading to an increase in their popularity. In the United States, the number of TAR surgeries has grown significantly over the years.
However, it’s important to note that as more TAR surgeries are performed, the rate of complications has also risen. Complications can vary widely, ranging from minor issues to more serious problems like implant fracture, infection, technical errors, implant shifting, dislocation, wound complications, and others. These complications can occur in anywhere from 1.3% to 50% of cases.
In cases where a TAR cannot be revised or salvaged, alternative options include ankle fusion (tibiotalar arthrodesis), fusion involving the ankle and heel bone (tibiotalocalcaneal arthrodesis), or in extreme cases, amputation. It’s essential for patients to discuss the potential risks and benefits of TAR surgery thoroughly with their orthopedic surgeon to make informed decisions about their treatment options.
Ensuring there’s enough healthy bone in the ankle is crucial for successful fusion after a total ankle replacement (TAR) surgery. Depending on the amount of remaining bone, different bone grafting techniques may be recommended. If the bone stock in the talus (the bone in the ankle) is greater or less than 2 cm, there are specific strategies to consider.
For small bone defects (<2 cm) where limb length shortening isn’t a concern, a fusion procedure can be done in place, with the option of adding graft material from nearby bones or the hip. It’s important to watch out for any impingement between the bones during fusion. If the bone defect is larger than 2 cm, a fusion using structural grafts is preferred. This method not only provides stability but also helps maintain proper limb length and keeps ankle muscles and tendons working effectively.
Structural graft options may include bone from the hip (iliac crest), the femur, or the lower leg (distal tibia). If there’s arthritis in the subtalar joint or the talus has collapsed due to bone death (osteonecrosis), a fusion involving the ankle and heel bones may be necessary. Your orthopedic surgeon will determine the best approach based on your specific condition and needs.
Result
As ankle replacement surgery becomes more common, orthopedic surgeons are increasingly challenged with managing complications and failures that may arise. When severe issues like bone loss, implant shifting, tissue problems, infection, or significant bone damage occur, the standard approach is to consider either a direct or staged fusion of the ankle joint.
When converting from ankle replacement to fusion, surgeons must address two key concerns: filling the void left by the removed implant and ensuring proper fixation of the fused bones. Various techniques have been explored, but there isn’t one universally perfect method.
Around two years post-surgery, more than 90% of patients showed radiographic evidence of successful fusion, regardless of the specific technique used. Moreover, overall patient satisfaction rates were high, with approximately 91.5% reporting positive outcomes. It’s important to note, though, that complications were seen in about 22% of cases. Your surgeon will discuss these findings with you and help determine the most suitable treatment approach based on your individual circumstances.
Among 193 patients who underwent revision surgery to fuse either the ankle or the tibiotalocalcaneal (TTC) joint, 84% successfully fused after their first fusion attempt. Importantly, they experienced significant improvements in their foot and ankle function, as measured by the AOFAS score. Notably, those who received bone grafts for ankle fusion had a 100% fusion rate after their initial surgery, while those undergoing TTC fusion had a lower rate of 50%.
For patients who required a second fusion attempt, the overall fusion rate was 62.5%, leaving only a small number without fusion. However, some patients chose not to undergo a second surgery despite successful pain relief, even though X-rays showed incomplete fusion. Notably, complications were rare in these cases, likely due to the absence of hardware.
In patients with bone defects smaller than 2 cm, the authors suggest using either bone from the hip (iliac crest) or donated bone with sturdy internal fixation, based on promising study results. However, it’s essential for surgeons to carefully evaluate this approach before proceeding, as it’s based on older studies with limited patient numbers and hasn’t been consistently replicated in current research. This technique is typically reserved for specific cases with good bone quality and minimal health issues, requiring precise surgical preparation and bone graft placement to ensure stability.
For patients with larger bone defects exceeding 2 cm, the recommended approach involves using hip bone grafts with internal fixation using screws, with additional plating if necessary for added stability.
The review included patients who were managed with varied techniques to arthrodesis the ankle and, at times, included the subtalar joint. The tibiotalocalcaneal arthrodesis fused in only 43% of patients. Of this group, the subtalar joint fused in 65% of patients (at first attempt), thus contributing to 10% of the failure rate.
Overall, these patients had lower satisfaction scores and higher complication rates, though it could not be said with statistical power that fusing the subtalar joint is a negative prognostic factor. This may indicate that perhaps the techniques to address the subtalar joint are inadequate; perhaps the subtalar fusion should be staged after the ankle has fusion. Alternatively, the patients who require a TTC fusion may be set up for failure by host factors (bone mineral density, medical comorbidities), the severity of their arthroplasty failure, and the large amount of tibia and talar bone loss.
Conclusion
When a total ankle replacement (TAR) doesn’t work out as expected, salvaging the ankle through fusion surgery can lead to positive outcomes and high satisfaction levels in the short term, provided that fusion is successful. Using bone graft fusion technique tends to have the best initial fusion rates with minimal complications.
In the future, it’s important for studies to include prospective comparisons between different surgical approaches or control groups. Using standardized outcome measures will make it easier to directly compare results and understand which methods work best for patients.
Do you have more questions?
What are the common causes of failed total ankle replacement (TAR)?
Common causes of failed total ankle replacement (TAR) include implant loosening, component wear, infection, instability, malalignment, and bone loss.
How is the decision made to proceed with ankle arthrodesis after failed TAR?
The decision to proceed with ankle arthrodesis after failed TAR is based on factors such as the extent of implant failure, patient symptoms, functional limitations, and surgical candidacy.
What are the goals of ankle arthrodesis following failed TAR?
The goals of ankle arthrodesis following failed TAR include pain relief, restoration of stability, improvement in function, and prevention of further joint deterioration.
What are the different surgical techniques used for ankle arthrodesis?
Different surgical techniques for ankle arthrodesis include open fusion, arthroscopic fusion, and minimally invasive fusion procedures using screws, plates, or intramedullary devices.
How is bone fusion achieved during ankle arthrodesis?
Bone fusion during ankle arthrodesis is achieved by removing any remaining cartilage from the joint surfaces, compressing the bones together, and securing them in the desired position until new bone growth occurs across the joint.
What is the typical recovery process after ankle arthrodesis?
The typical recovery process after ankle arthrodesis involves immobilization in a cast or brace for several weeks, followed by gradual weight-bearing and physical therapy to regain strength, mobility, and function.
What are the potential complications of ankle arthrodesis?
Potential complications of ankle arthrodesis include nonunion (failure of bone fusion), malunion (improper alignment of fused bones), infection, nerve injury, stiffness, and arthritis in adjacent joints.
Can ankle arthrodesis be performed as a revision procedure after previous failed fusion attempts?
Yes, ankle arthrodesis can be performed as a revision procedure after previous failed fusion attempts, but the success rate may vary depending on the underlying cause of failure and the condition of surrounding soft tissues.
How does ankle arthrodesis compare to other salvage procedures for failed TAR?
Ankle arthrodesis is one of the salvage procedures for failed TAR, with the goal of providing pain relief and functional improvement, but comparisons with other salvage options such as revision TAR or ankle arthroplasty revisions depend on individual patient factors and surgical outcomes.
Can ankle arthrodesis be performed using minimally invasive techniques?
Yes, ankle arthrodesis can be performed using minimally invasive techniques, such as arthroscopy or percutaneous fusion methods, which may offer advantages such as smaller incisions, reduced soft tissue trauma, and faster recovery times.
How long does it take for bone fusion to occur after ankle arthrodesis?
Bone fusion after ankle arthrodesis typically takes several months to complete, with the timing varying depending on factors such as patient age, bone quality, surgical technique, and post-operative rehabilitation.
What is the expected prognosis and long-term outcomes after ankle arthrodesis following failed TAR?
The expected prognosis and long-term outcomes after ankle arthrodesis following failed TAR depend on factors such as patient age, activity level, severity of joint degeneration, surgical technique, and rehabilitation compliance.
Are there any alternative treatments or procedures for failed TAR besides ankle arthrodesis?
Yes, alternative treatments or procedures for failed TAR may include revision TAR, ankle arthroplasty revisions with different implant designs, or salvage options such as ankle distraction arthroplasty or arthroscopic debridement, depending on the specific circumstances and patient preferences.
How does the presence of underlying conditions such as arthritis or osteoporosis affect the success of ankle arthrodesis?
The presence of underlying conditions such as arthritis or osteoporosis may affect the success of ankle arthrodesis by influencing bone quality, healing capacity, and the risk of complications such as nonunion or implant failure.
Can ankle arthrodesis be performed bilaterally if both ankles have failed TAR?
Yes, ankle arthrodesis can be performed bilaterally if both ankles have failed TAR, but careful consideration of patient factors, functional goals, and potential risks is necessary to ensure optimal outcomes and rehabilitation.
What is the role of physical therapy in the recovery process after ankle arthrodesis?
Physical therapy plays a crucial role in the recovery process after ankle arthrodesis by helping restore strength, mobility, and function, as well as improving gait mechanics and balance to optimize patient outcomes.
Are there any age limitations for undergoing ankle arthrodesis after failed TAR?
There are typically no strict age limitations for undergoing ankle arthrodesis after failed TAR, as long as patients are medically fit for surgery and have realistic expectations regarding the procedure’s goals and outcomes.
Can ankle arthrodesis be performed in patients with previous ankle surgeries or implants besides TAR?
Yes, ankle arthrodesis can be performed in patients with previous ankle surgeries or implants besides TAR, but the presence of hardware or bone alterations from prior procedures may pose challenges and require individualized surgical planning.
