Raising Questions About Ankle Arthrodiastasis
I read the recent article “A New Solution For The Arthritic Ankle?” (see page 36, December 2005) with interest. I applaud the authors for their work and agree that this is an option for patients with degenerative joint disease of the ankle.
George R. Vito, DPM, et. al., accurately point out that there are few surgeons who have total ankle implant training and regularly perform this procedure. I have had years of training with the inventor of the only FDA approved ankle implant, and have performed a tremendous number of these procedures successfuly.
Unfortunately, the authors’ review of total ankle arthroplasty articles is incomplete. I understand that it would be impossible to cite every reference. However, Knecht, in a 2004 article in The Journal of Bone and Joint Surgery, showed an 11 percent revision rate and 92 percent overall satisfaction rate with the Agility (DePuy) total ankle. This was at a mean follow-up of nine years.
Dr. Vito and his co-authors summarize implant arthroplasty by citing Salzman’s 2000 article and stating “the literature regarding ankle implants suggests that improvements in implant design are needed.” However, there are many more recent papers, such as the aforementioned Knecht paper, that show favorable outcomes. Implant design improvement is an appropriate and even necessary goal of any system, and there have been multiple and ongoing design improvements with the Agility implant.
Additionally, the authors claim the combination of arthrodiastasis and joint fluid replacement is a minimally invasive operation. While the incisions may be minimally invasive, is this procedure really minimally invasive to the patient (see the photo on page 38 of the article)? Other than the benefit of joint sparing, how much less invasive is this treatment compared to an implant or fusion? These are big, clumsy, very invasive devices to a patient’s life.
Also, the cited statistic of only 17 percent pin tract infections is very low. In my experience, almost all pins and wires of external fixators become at least superficially infected in a five-week course and a headache at best. On that same note, five weeks of treatment is significant. Six weeks after a total ankle arthroplasty, the patient is beginning to bear weight.
In looking at the pre- and postoperative X-rays provided, this patient has severe end-stage ankle arthritis with a significant varus deformity. Even if there is some reparative process to the articular cartilage that goes on as the authors eloquently discuss in the article, I cannot imagine that this patient will not need an implant or arthrodesis in the very near future. Furthermore, for this patient, delaying an ankle implant can be detrimental to the patient as the longer this deformity is allowed to progress, the more damage to surrounding soft tissue and bone occurs, making an implant much more difficult if not impossible. It seems that a less advanced scenario with no deformity would lend itself more favorably to your study treatment.
In the conclusion, the authors claim that, “One can use these minimally invasive procedures to treat ankle arthritis and delay, if not avoid altogether, the need for ankle fusion.” I can accept that this may delay joint destructive procedures but the follow-up is only one year. At another point in the article, the authors claim they “are unable to determine how long the positive trend in pain relief will continue.”
I congratulate Dr. Vito, et. al., on their innovative work. I believe that arthrodiastasis and joint fluid replacement is a tool to delay joint destructive procedures in the appropriate patient. However, in my hands, joint replacement is a very reliable option when “conservative” measures such as arthrodiastasis fail. In fact, survivorship at 10 years is approaching that of hips and knees in the experienced surgeon’s hands.
—Jerome K. Steck, DPM, FACFAS
Assistant Clinical Professor of Surgery,
University of Arizona
Ankle & Foot Institute of Arizona
Institute for Peripheral Nerve Surgery