Mortality in patients with diabetic neuropathic osteoarthropathy (Charcot foot)

Abstract

To determine the mortality of a population of patients diagnosed with Charcot neuropathic osteoarthropathy managed by a single specialist unit and to compare the results with a control population. We have undertaken a retrospective analysis of all cases of Charcot foot on the comprehensive database which has been maintained at the specialist diabetic foot clinic at the City Hospital, Nottingham since 1982. Survival and the incidence of amputation (major and minor) was compared with a control population referred with uncomplicated neuropathic ulceration. Controls were individually matched for gender, age (+/-2 years), disease type, disease duration (+/-2 years) and year of referral (+/-3 years). Forty-seven cases (21 female, 26 male) of Charcot foot were identified, of whom 18 (38.3%) had Type 1 diabetes. Mean age and disease duration at presentation were 59.2 +/- 13.4 (sd) and 16.2 +/- 11.2 years, compared with 59.7 +/- 12.6 and 16.3 +/- 11.2 years, respectively, in the controls. Twenty-one (44.7%) of those with Charcot had died, after a mean interval of 3.7 +/- 2.8 years. This compared with 16 (34.0%) after a mean 3.1 +/- 2.7 years in the control group. Mean duration of follow-up in the survivors was 4.7 +/- 4.9 years (Charcot) and 5.3 +/- 3.9 years (controls). A total of 11 (23.4%) Charcot patients had had a major amputation on the side of the index lesion, compared with five (10.6%) controls. There was no difference between the two groups (P > 0.05, Chi-square). The mortality in this group of patients with Charcot foot was higher than expected. Nevertheless, there was no difference between those with Charcot and those with uncomplicated neuropathic ulceration. It is possible that it is neuropathy, rather than Charcot osteoarthropathy, which is independently associated with increased mortality in diabetes. The mechanism underlying any such association is not known. There is a need for a formal, prospective, multicentre study to investigate the life expectancy and cardiovascular risk of those with Charcot osteoarthropathy.