Risk Factors and Characteristics of Recalcitrant Osteomyelitis Following Initial Surgical and Antibiotic Treatment.

Abstract

To evaluate the injury, patient, and microbiological characteristics that place patients at risk for recalcitrant fracture related infection and osteomyelitis despite appropriate initial treatment. Retrospective Chart Review. Three level I trauma centers. Two hundred and fifty-seven patients undergoing surgical debridement and antibiotic therapy for osteomyelitis from 2003 to 2019. Patients were categorized as having undergone serial bone debridement if they had two separate procedures a minimum of six weeks apart with a full course of appropriate antibiotics in between. Patient records were reviewed for age, injury location, body mass index (BMI), smoking status, comorbidities, and culture results including the presence of multidrug resistant organisms (MDRO) and culture-negative osteomyelitis. A total of 257 patients were identified; 49% (n=125) had a successful single course of treatment, and 51% (n=132) required repeat debridement for recalcitrant osteomyelitis. At the index treatment for osteomyelitis, the most common organisms in both groups were Methicillin-resistant (MRSA) and Methicillin-sensitive Staphylococcus aureus (MSSA). There was no significant difference in incidence of polymicrobial infection between the two groups (25% vs 20%, p=0.49). The most common organisms cultured at the time of repeat saucerization remained MRSA and MSSA, however, the same organism was cultured from both the index and repeat procedure in only 28% (n=37) of cases. Diabetic patients, IVDU, delay to diagnosis, and open fractures of the lower leg are independent risk factors for failure of initial treatment of post-traumatic osteomyelitis. Successful eradication of fracture related infection and post-traumatic osteomyelitis is difficult and fails 51% of the time despite standard surgical and antimicrobial therapy. While MRSA and MSSA remain the most common organisms cultured, patients who fail initial treatment for osteomyelitis often do not culture the same organisms as those obtained at the index procedure.