Could surgery prevent amputation?
Ulcer prevention is the key to amputation prevention in patients with Charcot arthropathy, according to research from Chicago that raises the question of whether pre-emptive surgical correction of deformities is warranted in Charcot patients.
Investigators from Loyola University reviewed 911 cases of Charcot arthropathy and 15,117 cases of diabetic foot ulcer in the absence of Charcot, from a national Department of Veterans Affairs database. During a five-year follow up period, 59% of the Charcot cases were treated for foot ulceration.
Crude lower extremity amputation rates were similar for patients with Charcot arthropathy (14.7%) and those with foot ulcers in the absence of Charcot (14.5%). However, further analysis suggested that most of the amputation risk in the Charcot group could be attributed to the development of foot ulcers.
Compared to patients with Charcot arthropathy and no foot ulcer, the relative risk of amputation was seven times higher in patients with foot ulcers in the absence of Charcot, and nearly 12 times higher in those with both Charcot and a diabetic foot ulcer. In patients over the age of 65, the amputation risk was nine times higher in those with ulcer alone and 13 times higher in those with both Charcot and diabetic foot ulcer.
The findings contrast with those of a meta-analysis in the December 1999 issue of the Journal of Orthopedic and Sports Physical Therapy, in which researchers from Washington University in St. Louis estimated an amputation rate of 6.6% in Charcot patients
“Patients with Charcot foot have a higher risk of amputation than previously thought,” said Michael Pinzur, MD, a professor of orthopaedic surgery and rehabilitation at Loyola University, who presented his group’s findings in July at the annual meeting of the American Orthopaedic Foot & Ankle Society. The Loyola results were also published in the January issue of Diabetes Care.
The discrepancy underscores the likelihood that Charcot arthropathy treatment nationwide may be very different from Charcot treatment at an institution dedicated to high-level diabetes care and research. Investigators from one such institution, Baylor University Medical Center in Dallas, reported in a separate AOFAS presentation their four year outcomes for 340 Charcot arthropathy patients, which included very low rates of both ulceration and amputation.
Out of 340 Charcot patients, only 56% underwent surgery during the follow up period, and fewer than 5% of those procedures were amputations, said Alexander Rabinovich, MD, a foot and ankle fellow in the department of orthopaedic surgery at Baylor, who presented the findings. By the end of the study period, 97.4% of patients were ambulatory.
“Excellent outcomes with predominantly conservative treatment of Charcot foot can be achieved,” Rabinovich said. Conservative treatment modalities included total contact casting, bracing, diabetic footwear, and insoles.
Ulcers were present at the first visit in 34% of patients, but only 8% at the last visit. Rabinovich also noted a relatively high rate of forefoot ulcers, which would be more likely to result from neuropathy than from a Charcot deformity.
The Baylor outcomes illustrate the importance of ulcer prevention in patients with Charcot arthropathy, Pinzur said.
“If you have Charcot and you don’t have an ulcer, as in the Baylor experience, then you can get very good results nonoperatively,” he said. “Once the patient develops an ulcer, that’s the beginning of the downslide.”
But given the higher rates of amputation seen in the Loyola study’s national VA population and the emergence of ulceration as a contributing risk factor, Pinzur suggested that in some clinical settings more aggressive preventive measures may be warranted.
“The next question,” he said, “is should you correct the deformity to prevent the ulcer?”