Things are changing in the treatment of severe ankle arthritis. What was once treated with ankle fusion can now be managed with a joint replacement. Improved surgical techniques and better implant designs have made the shift possible. But the question remains: are the long-term results comparable?
That’s what the authors of this study set out to see for themselves. They compared two groups of patients with severe, disabling ankle arthritis that did not respond as hoped to conservative care. As you might suspect, one group had the fusion procedure.
The second group received a total ankle replacement (TAR), also known as an ankle arthroplasty. The ankle replacement group did not all get the same type of implant. There were four different implants used. Not everyone had the same surgical approach either. Some patients had open incision surgery while others were treated with arthroscopy.
Besides looking at final function after two years, they also paid attention and compared complications along the way for both groups. X-rays were used to evaluate the joint itself. CT scans added information on the status of the healing process. The Ankle Osteoarthritis Scale (AOS) was used as a measure of pain, function, and disability. Before surgery and postoperative values were recorded for each patient.
Everyone in both groups had significant (and fairly equal) improvements. Pain relief, increased ankle range-of-motion, and improved function (e.g., walking, going up or down stairs, managing uneven terrain) were observed. The complication rate was high for both groups, but twice as high in the ankle arthroplasty group compared with the fusion group.
What kind of complications are we talking about? Well, fractures, skin and deep wound infections, and chronic pain after surgery are possible with either procedure. Likewise, infection that spreads to the bone called osteomyelitis can develop after any surgical procedure that disrupts bone as these two procedures do. Then there is the risk of cutting or damaging nerves and/or blood vessels.
Ankle fusion is well-known for complications such as off angles, poor alignment and deformity, nonunion, and arthritis in the surrounding joints. Altered gait or abnormal walking pattern is typical with an ankle fusion. And of course, activities like jogging or running will never be the same if even possible.
Ankle arthroplasty (total ankle replacement) comes with its own set of potential problems. Common complications with ankle joint replacement include loosening of the implant, impingement (pinching), and malalignment. There can also be subsidence (implant sinks down into the bone), the wrong implant size used, and/or excessive wear on any part of the implant. Though rare, the implant can also fracture or break as well.
Let’s take a look at the results after surgery and after all the complications were noted and treated. Everyone was followed for at least two years and some patients for up to 10 years. As it turned out, the affect different complication varied. For example, an implant that had come loose often required a second surgery, whereas even a deep infection could be treated and cleared up with antibiotics.
Anyone in either group with ongoing pain and discomfort from a nerve lesion caused by the surgery was less likely to be satisfied with the long-term results compared with patients who had less significant complications.
The authors concluded that some complications can have significant effects on outcomes in both groups (fusion and joint replacement). Patients receiving a total joint replacement are more likely to have problems. Older, less active adults seem to weather the complications better than younger patients who expect to do more and expect to have fewer problems so are surprised when they have any.
Studies like this help point the direction for future comparisons. One of those will be to compare the results between and among the various implant types. The goal now is to reduce the high level of complications following fusion or ankle arthroplasty (replacement).