Retrospective Study on Multidrug-Resistant Bacterium Infections After Rigid Internal Fixation of Mandibular Fracture.

Purpose: To retrospectively investigate infection by multidrug-resistant bacteria (MDRB) after rigid internal fixation (RIF) of mandibular fracture and determine risk factors and cure methods.

Patients And Methods: From 2009 through 2014, 933 patients with mandibular fracture were enrolled in the study. Fifteen variables were statistically analyzed using univariate and multivariate logistic regression methods to investigate risk factors for MDRB infection after RIF of mandibular fracture.

Results: Sixteen of 933 patients (1.71%) developed MDRB infection. Of these, 6 were infected with methicillin-resistant Staphylococcus aureus (MRSA), 6 with multidrug-resistant Pseudomonas aeruginosa (MDR-PA), 1 with extended spectrum β-lactamase-producing Klebsiella pneumonia, 1 with extended spectrum β-lactamase-producing Escherichia coli, 1 with multidrug-resistant Acinetobacter baumannii, and 1 with multidrug-resistant Enterobacter cloacae. Univariate analysis showed that risk factors of MDRB infection after RIF of mandibular fracture were age, obesity (body mass index ≥25 kg/m(2) for Asians), polytrauma (Injury Severity Score >16), preoperative infection, open fractures, comminuted fractures accompanied by other facial fractures, and teeth involving the fracture line. Multivariate logistic regression analysis showed that obesity, preoperative infection, and open fractures were independent risk factors of MDRB infection. After systemic anti-infection treatments with vancomycin, piperacillin, tazobactam, local drainage, and debridement, the infections were under control. Fourteen patients achieved clinical healing at an average time of 8.71 months, and 2 did not achieve clinical healing. The overall mean follow-up was 18.81 months.

Conclusion: MDRB infections occurring after RIF of mandibular fracture were caused mainly by MRSA and MDR-PA. Obesity, preoperative infection, and open fractures were the main risk factors. To lower risk, surgical debridement should be performed sooner once acute infection has been controlled, stable fixation should be achieved with the smallest amount of internal fixation material, the blood supply should be protected, and a reconstruction plate should be used to fix sites with greater stress or large comminuted fracture.