Risk factors of pin tract infection during bone transport using unilateral external fixator in the treatment of bone defects

The bone transport using the unilateral external fixator, one of the Ilizarov techniques, is widely practiced in lower limb reconstructive surgery. Pin tract infection (PTI), one of most common complication, has become the important postoperative problems which plague clinicians gradually.A group of 130 patients who received bone transport surgery for tibia or femur defects using the unilateral external fixation (Orthofix limb reconstruction system, Verona, Italy) and met the inclusion criteria were selected for the study from 2015 to 2019. Regular pin tract care was performed twice a day, and the conditions of the pin tract were evaluated by the same observer using clinical appearance criteria. The Saw's classification of PTI was used to assess the condition around screws. After the data were significant by the T-test or Pearson's Chi-square test analyzed, odds ratios were calculated using logistic regression tests to describe factors associated with the diagnosis of PTI.Ninety-one males and thirty-nine females with a mean age of 43 years (range 28-58 years) were included in this cohort. 7816 observations were documented from 12 to 36 months, and 58 cases (44.6%) of PTI (thirty-nine cases in grade 1, 17 cases in grade 2, and 2 cases in grade 3). The top five risk factors were agricultural work (OR 1.86, CI 0.94-2.39), non-urban living (OR 1.75, CI 1.24-3.26), male (OR 1.71, CI 1.02-2.31), smoking (OR 1.53, CI 0.76-1.89), and diabetes (OR 1.26, CI 1.12-2.64). No long-term sequelae were observed at the latest clinical visit.Occupation, gender, living environment (non-urban), smoking, and diabetes were the top five significant risk factors for PTI in the period of bone transport using unilateral external fixation. Awareness of predictable risk factors of PTI is beneficial to avoid or early detect the severe complications which can affect the effectiveness.