Influence of osteomyelitis location in the foot of diabetic patients with transtibial amputation.

Abstract

To evaluate the prevalence of osteomyelitis in different areas of the foot and the possible correlation between localization and outcome of major amputation. From January 2008 to December 2010, a total of 350 diabetic patients were admitted to our diabetic foot unit for the surgical treatment of osteomyelitis. Osteomyelitis was diagnosed when both the probe-to-bone maneuver and plain radiography were positive. In all of these patients, osteomyelitis was confirmed by histological examination. Osteomyelitis was localized to the forefoot in 300 (85.7%) patients, to the midfoot in 27 (7.7%) patients, and to the hindfoot in the remaining 23 (6.75) patients. On average, foot lesions had developed 6.6 ± 5.6 months before admission to our unit. Transtibial amputation was performed in 1 (0.33%) patient with forefoot osteomyelitis, in 5 (18.5%) patients with midfoot osteomyelitis, and in 12 (52.2%) patients with osteomyelitis of the heel (χ(2) = 128.4, P < .001). Multivariate analysis showed the independent role that osteomyelitis in the heel region had in major amputation outcome (odds ratio 15.3; P < .001; confidence interval, 17.4-5336.0), dialysis treatment (odds ratio 6.3; P = .012; confidence interval, 2.5-1667.2), and leukocyte count greater than 10(3) mm(3) (odds ratio 2.25; P = .036; confidence interval, 1.1-76.6). We found a higher rate of transtibial amputation when osteomyelitis involved the heel instead of the midfoot or forefoot in diabetic patients. Level III, retrospective comparative series.