Neuropathy and Poorly Controlled Diabetes Increase the Rate of Surgical Site Infection After Foot and Ankle Surgery

SLR - October 2014 - Kristina T. Ruff

Reference:  Wukich DK, Crim BE, Frykberg RG, Rosario BL Neuropathy and Poorly Controlled Diabetes Increase the Rate of Surgical Site Infection After Foot and Ankle Surgery. J Bone Joint Surg Am. 2014 May 21; 96(10): 832-9.

Scientific Literature Review

Reviewed By: Kristina T. Ruff, DPM
Residency Program: New York Hospital of Queens

Podiatric Relevance: As podiatric physicians, diabetes mellitus is a condition encountered on a daily basis. The rate at which diabetes has been growing is alarming. An estimated 8.3percent of the population currently has the disease with the prevalence increasing to 26.9 percent for patients over the age of sixty-five years. Diabetes and/or hyperglycemia are associated with numerous comorbidities such as peripheral neuropathy, Charcot neuroarthropathy, peripheral arterial disease and foot ulcers. Increased infection rates have been observed in diabetics due to increased vulnerability secondary to these comorbidities. In particular, diabetic patients after ankle fractures and major foot/ankle surgery have shown increased rates of infection. A previous retrospective controlled study revealed that there are higher rates of surgical site infections after foot and ankle surgery in diabetics with complications, compared with uncomplicated diabetics and non-diabetics. The aim of this prospective study was to corroborate with the findings of the previous retrospective study. The secondary objective was to assess non-diabetics with and without peripheral neuropathy and the effect on surgical site infections.

Methods: From 2008 to 2011, two thousand and sixty consecutive surgical cases were evaluated. Patients were divided into four groups. Group 1 included non-diabetic patients without peripheral neuropathy (n=1536).  Group 2 included non-diabetic patients with peripheral neuropathy (n=201). Group 3 included patients with diabetes, but no complications. Group 4 included patients with diabetes who had at least one complication of diabetes. Multiple methods of statistical analysis were used to evaluate the four groups.

Results: Surgical site infections were seen in 64 (3.1 percent) of the 2060 patients. Mild infections were seen with fifteen (4.6 percent) of the 323 patients with Diabetes compared to twenty-nine (1.7 percent) of the 1737 without diabetes. Severe infections were seen in eleven (3.4 percent) of the 3232 patients with diabetes compared to nine (0.5 percent) of the 1737 patients without diabetes. There was a 7.25-fold increased risk of surgical site infections compared with non-diabetic patients without neuropathy and a 3.72-fold increased risk of surgical site infection compared with diabetic patients without complications. Group 2 patients with non-diabetic neuropathy were found to have a 4.72-fold increased risk of surgical site infection compared with non-diabetic patients without neuropathy. Patients with increased HbA1c of >8% was associated with 2.7-fold increased risk of surgical site infection.

Conclusions: This study validated what previous studies have shown, namely that complicated diabetes increases the risk of surgical site infection compared with the risk for non-diabetic patients without neuropathy and patients with uncomplicated diabetes. The highest prevalence of surgical site infections was observed in patients with complicated diabetes and patients with non-diabetic neuropathy. This demonstrated that neuropathy was found to be a major risk factor for surgical site infections, even in patients without diabetes. Poor long-term glycemic control also revealed an increased risk of surgical site infections, confirming need for long term glycemic management of diabetic patients.