Hemicallotasis in Tibial Osteotomy using External Fixation. Patients, Pin Site Infection and Pin Site Care

External fixation has been more commonly used during the last decades for correction of bone and soft tissue deformities and in frcture healing. The most common complication of external fixation is pin site infection. Two hundred and nineteen younger and/or physically active patients (mean age 53 (18-75) years) suffering from knee osteoarthritis (OA) or knee deformities operated on by hemicallotasis osteotomy (HCO) were included. In paper I, a commonly used daily pin site care performed by a district nurse was compared to weekly pin site care in the outpatient clinic. Sodium chloride (9 mg/ml) was used as cleansing agent, and prophylactic antibiotics was given for 14 days. There were no differences between daily and weekly pin site care. The clinical pin site infection rate was 15% minor infections and 30% of the pin sites had positive bacterial cultures. The mean total use of antibiotics during the treatment period was 47 days per patient. In paper II, sodium cloride (9 mg/ml) was compared to chlorhexidine solution (2 mg/ml) as cleansing agent and prophylactic antibiotics were reduced to 3 days. In the chlorhexidine group there were less clinical infections, less positive cultures and lower total mean use of antibiotics as compared to the sodium group. In paper III, 3 days of prophylactic antibiotics was compared to a singgle dose. Chlorhexidine (5 mg/ml with alcohol, 70 % ethanol) was used as cleansing agent. There were no differences between 3 days and one dose of prophylactic antibiotics. In paper IV, the healing time and complications that cause longer time in external fixation were investigated in smokers and non-smokers. Smokers had longer healing time and more complications than non-smokers. Smoking was the single most important preoperative risk factor for postoperative complications. In paper V, patients suffering from knee OA were prospectively followed up during the first two years, with special focus of the treatment time in external fixation. Pain, function and knee related quality of life were assessed with the knee-specific questionnaire, Knee injury and Knee Osteoarthritis Outcome Score (KOOS). The patients showed large improvements in self-rated pain, function and quality of life, most of which were seen already during the immediate postoperative period when the external fixation was still used. The clinical pin site infection rate, rate of positive cultures and total use of antibiotics could be redused by changing different factors relating to pin site care. Prolonged prophylactic antibiotics had no benefit. The negative effect of cigarette smoking is an important factor to be considered in patient selection for HCO, and should be an important part of the preoperative information. The treatment by HCO reduced the pain and improved function and quality of life already during the treatment in external fixation and continued during the 2-year follow-up