Reamputation after minor foot amputation in diabetic patients: risk factors leading to limb loss.

The prevalence of lower extremity reamputation in diabetic patients has been well-documented. We sought to determine the risk factors for major lower extremity amputation (LEA) after minor foot amputation in diabetic patients. We studied 163 diabetic patients who had undergone an initial minor foot amputation and then had undergone at least 1 subsequent major or minor LEA. The patients were separated into a minor LEA group (initial minor LEA followed by at least 1 subsequent minor LEA) and a major LEA group (initial minor LEA followed by at least 1 subsequent major LEA). We then studied the possible risk factors for both groups. The possible risk factors analyzed were age, glycemic control, kidney function, previous kidney or kidney-pancreas transplantation, smoking history, and presence and severity of peripheral arterial disease (PAD). No statistical significance was found between the 2 groups for hemoglobin A1c, smoking status, chronic kidney disease, end-stage renal disease requiring dialysis, kidney or kidney-pancreas transplantation, or vascular intervention (peripheral arterial bypass). In the minor group, 22.23% had severe PAD. In the major group, 71.15% had severe PAD. This was statistically significant (p < .001). The average interval to major amputation in those without PAD, mild to moderate PAD, and severe PAD was 1,180.9, 591.0, and 559.6 days, respectively. This demonstrates the importance of assessing the peripheral vascular status in all diabetic patients with minor LEA. Early referral to a vascular surgeon might delay (or prevent) major LEA.

Rate of residual osteomyelitis after partial foot amputation in diabetic patients: a standardized method for evaluating bone margins with intraoperative culture.

The purpose of this study was to determine the rate of residual osteomyelitis after different foot amputations in diabetic patients with a standardized method of determining a clean bone margin. This retrospective observational pilot study evaluated 27 diabetic patients who had a forefoot amputation (toe, partial ray, or transmetatarsal) for osteomyelitis at our institution from January 1, 2010, to August 1, 2011. A standardized method was used intraoperatively to determine if bone margins were negative for residual osteomyelitis. Short-term outcomes were assessed. Negative outcomes included wound dehiscence, re-ulceration, re-amputation, or death. The overall rate of residual osteomyelitis was 40.7% (11/27 patients). Patients who underwent toe amputation with joint disarticulation had a positive margin culture rate of 23.1% (3/13). Patients who underwent partial metatarsal or transmetatarsal amputation had a positive margin culture rate of 57.1% (8/14). Although twice as frequent, this was not considered to be statistically significant (p = .1201). Overall, 48.1% (13/27) of patients were considered to have poor outcomes, and 9/11 (81.8%) patients with a positive bone margin had poor outcomes, whereas only 4/16 (25%) patients with a negative bone margin had poor outcomes. This difference was considered statistically significant (p = .0063). Although this is a pilot study, our results do confirm the high incidence of residual osteomyelitis with associated poor outcomes. Based on our data, we recommend routine standardized bone margin culture after thorough debridement and irrigation.