Patients and data collection

We reviewed the medical records of consecutive patients with diabetes who underwent open reduction and internal fixation for the treatment of ankle fracture at our hospital between May 2003 and November 2013. Inclusion criteria were patients who underwent blood testing, including assessment of fasting blood glucose (FBG), glycated hemoglobin (HbA1c), and cholesterol levels, as part of a regular check-up before surgery and again more than 2 times after ankle fracture surgery. Exclusion criteria included concomitant injury, pilon fracture, inability to ambulate before or after surgery, and postoperative complications requiring repeat surgery or prolonged immobilization. Age at the time of surgery, sex, body mass index (BMI), and type of ankle fracture were obtained by medical record review. The type of ankle fracture was divided into 2 categories: single (medial or lateral malleolar) and multiple (bi- or trimalleolar). All venous blood sampling was performed in a fasting state in the morning according to our protocol for regular assessment of diabetes. Blood test results were divided into pre- and postoperative and were grouped by month.