Age, Diabetes Affect Arthrodesis Outcomes in Charcot Patients



LOS ANGELES – Older Charcot patients may fare better than young ones after arthrodesis of the foot and ankle, according to Dr. Dane Wukich, a University of Pittsburgh orthopedic surgeon.

In a study comparing Charcot patients with and without diabetes mellitus, those with diabetes fared much worse, as did patients who smoked or had peripheral neuropathy, Dr. Wukich reported at the Diabetic Foot Global Conference.

Dr. Dane Wukich

Such data could help surgeons determine which Charcot foot patients are the best candidates for surgery, he said. "Surgical treatment is controversial, and I think it lacks sound scientific evidence to support what we do," he said at the conference, presented by Valley Presbyterian Hospital, Van Nuys, Calif.

But helping Charcot patients is important because they report themselves to be more disabled than people with Parkinson’s, heart failure, or hemodialysis (Foot Ankle Int. 2005;26:717-31).

The surgery is challenging, with a high risk of complications, said Dr. Wukich. But in his experience, patients’ expectations are relatively low. Surgeons aim to eliminate pain, avoid amputation, and maintain ambulation. "Limb salvage should be 90% with proper technique and good patient selection," he said.

In a review of the literature on the surgical management of Charcot foot, Dr. Wukich and his colleagues found about 95 studies looking at 1,129 diabetic patients who had surgery. But there were no prospective trials; most of the studies were expert opinions and case reports, or at best case series, and half the reports came from only four surgeons.

"When people get up and talk to you about these things, half the evidence is based on opinion," Dr. Wukich warned. "It’s really not sound scientific evidence."

Such as it is, the literature suggests that the results of surgery in the acute stages are encouraging, he said. "But there has never been a study comparing operating on somebody when it first happens to operating on somebody in the chronic phase. So it’s inconclusive at this time. We have no evidence telling you when you should operate."

Most procedures – 59% – were in the midfoot, with 29% in the ankle and relatively few in the hindfoot.

Using grades from A to D, with A meeting the strongest standards for evidence, the researchers attached a grade of C to the evidence for exostectomy, in which surgeons shape bone on the bottom of the foot. And this is a relatively simple procedure.

They gave a B to Achilles tendon lengthening. "It reduces forefoot pressure. It improves the alignment of the ankle with regard to the forefoot," said Dr. Wukich.

They also gave a grade of C to arthrodesis, in which bones are fused to reduce pain, instability, and recurrent ulcers. "We know that about 25% of these people are not going to fuse properly," he said.

As for fixation, the researchers gave it an I for incomplete. "We get all excited about these new technologies, and we spend $12,000 just putting a frame on a patient, but quite honestly I can’t sit here and tell you based on all the evidence whether I should use internal fixation or external fixation," said Dr. Wukich.

Finding so little of use in the literature, Dr. Wukich and his colleagues undertook their own study of arthrodesis of the foot and ankle, comparing 74 diabetes patients to 74 patients without diabetes. The diabetes patients weighed more, but they were closely matched to the comparison group in terms of age, sex, and previous surgery.

Comparing the complication rates, the researchers found that diabetes conferred a risk factor of 2.9.

However, age was associated with fewer complications. "That’s a surprising fact, because you would expect the opposite," said Dr. Wukich. "Perhaps it’s that our older patients are less active postoperatively that results in fewer complications."

Diabetes patients were 17 times as likely to get an infection. In addition, patients with a hemoglobin A1c level of more than 7% were five times as likely to suffer an infection. Not surprisingly, tobacco use, peripheral neuropathy, and peripheral artery disease also increased the risk of infection.

Turning to noninfectious complications, such as hardware failure, symptomatic hardware, and failure to fuse, the researchers found that patients with diabetes, a history of tobacco use, or a history of a transplant were more likely to suffer.

"Diabetes and tobacco are a bad combination," said Dr. Wukich. "That’s something you can tell the patient."