Prognostic difference between soft tissue abscess and osteomyelitis of the foot in patients with diabetes: data from a consecutive series of 452 hospitalized patients.

Abstract

From January 2008 to December 2010, 452 patients with diabetes were admitted to our diabetic foot unit because of deep soft tissue abscess (group A: n = 210) or chronic osteomyelitis (group B: n = 242). Patients from group A underwent emergency debridement in the operating room. Patients from group B underwent elective surgery. Twenty-six (5.8%) major amputations were performed: of these, 18 (8.57%) were performed in patients from group A and 8 (3.31%) were performed in patients from group B (p = .024). Multivariate analysis showed the independent role on amputation outcome of the abscess (odds ratio, 2.64; p = .029; confidence interval [CI] 1.11 to 6.28), dialysis treatment (odds ratio, 3.17; p = .039, CI 1.06-9.51), and C-reactive protein > 0.5 mg/dL (odds ratio, 3.75; p = .022, CI 1.21-11.64). In group A, 43 (22.6%) patients healed only with drainage, and 147 (70.0%) minor amputations were performed: 53 (36.1%) at the level of the forefoot and 94 (63.9%) at the level of the midfoot. In group B, 234 (96.7%) minor amputations were performed, 208 (88.9%) at the forefoot and 26 (11.1%) at the midfoot level (p < .001). Fourteen postoperative complications occurred in patients from group A and 2 in patients from group B (p < .001). In group A, 3 patients died during hospitalization, 1 from septic shock and 2 from sudden death. None of the group B patients died. This study demonstrates that the severity of a foot soft tissue abscess is not comparable with that of a chronic osteomyelitis not only because of a higher rate of major amputation, but also because of a much more proximal level of minor amputation.