Inside Insights On Ankle Replacement Surgery
Ankle arthritis has been the subject of much research and researchers have made a great deal of progress in this area in the past 50 years. In the past, physicians primarily treated post-traumatic arthritis, which accounts for much of the cause of ankle arthritis, with casting. This often caused malalignment and poor articular position, resulting in rapid arthritis of the hindfoot and ankle.
With the advent of internal fixation and external fixation advances, proper anatomic alignment of the hindfoot and ankle has resulted in a dramatic decrease in the rate of post-traumatic arthritis. This being said, the aging population and the resulting baby boomer generation being healthier and more active has resulted in more cases of degenerative age-related arthritis. The numbers of patients with osteoarthritis of the ankle will likely continue to grow as patients live longer and want to be active for a longer period of their lives.
The main options for ankle arthritis have been: lubrication injections and bracing for conservative care; spur removal and joint clean-up for early cases of arthritis; cartilage replacement in minor arthritis cases; and fusion or ankle replacement in severe cases. The idea of ankle replacement has been low on the consideration ladder for severe cases due to the poor outcome of replacement cases in the mid-‘70s and the need for extensive numbers of revision cases in those early ankle replacements.
In the past 15 years, the need for more research and the prospective market for a good ankle replacement system have produced several replacement options with excellent overall outcomes. Each replacement option has positive and negative factors. I will try to provide a guide with regard to three replacement options that I use in my practice.
Keys To Proper Patient Selection
Initially, one needs to consider proper patient selection for ankle replacement. The patient needs to be relatively healthy for surgery and not be morbidly obese. Patients need to have good circulation and no peripheral neuropathy. The patient should also have a well positioned ankle with no major deformity.
Ideally, these patients should be over the age of 55, have a sedentary lifestyle/job and only participate in recreational activity that is not considered high impact activity. However, with the improvements in ankle replacement in the past 15 years, the envelope for the ideal patient has changed. A gray area now exists. One can now consider ankle replacement in certain cases for patients younger than 55. While we have no age cutoff in our practice, we do require a sedentary lifestyle and low-impact exercise. We also warn younger patients of the potential for fusion or revision replacement in the future.
The level of deformity has also been challenged. We often see post-traumatic patients with severe angular deformity who require correction of the angular deformity prior to being eligible for ankle replacement surgery. Often, we also have to realign the foot under the ankle to allow for proper function of the ankle replacement. This may require one surgery at the time of the replacement or there may need to be a two-part surgery.
We also try not to operate on morbidly obese patients due to the increased stress on the ankle but there is no true weight limit for ankle replacement consideration at this time.
I believe the best tactic is to consider all of the situations as a whole. One should pick those patients who understand the risks and rewards of replacement versus fusion, and feel that the added value of motion outweighs the single treatment benefit and dramatic decrease in pain resulting from a fusion.