Role of Suppressive Oral Antibiotics in Orthopedic Hardware Infections for Those Not Undergoing Two-Stage Replacement Surgery.

Background.  The use of suppressive antibiotics in treatment of orthopedic hardware infections (OHIs), including spinal hardware infections, prosthetic joint infections, and infections of internal fixation devices, is controversial. Methods.  Over a 4-year period at 2 academic medical centers, patients with OHI who were treated with debridement and retention of hardware components, with single-stage exchange, or without surgery were studied to determine whether use of oral antibiotics for at least 6 months after diagnosis impacts successful treatment of the infection at 1 year after diagnosis. Results.  Of 89 patients in the study, 42 (47.2%) were free of clinical infection 1 year after initial diagnosis. Suppressive antibiotics used for at least 6 months after diagnosis was not associated with being free of clinical infection (adjusted odds ratio [aOR], 5.29; 95% confidence interval [CI], .74-37.80), but being on suppressive antibiotics at least 3 months after diagnosis was associated with being free of clinical infection (OR, 3.50; 95% CI, 1.30-9.43). Causative organisms impacted the likelihood of success; patients with methicillin-resistant Staphylococcus aureus as well as with Gram-negative rods were both less likely to have achieved clinical success at 1 year after surgery (aOR = 0.018, 95% CI = .0017-.19 and aOR = 0.20, 95% CI = .039-.99, respectively). Conclusions.  Oral suppressive antibiotic therapy in treatment of OHI with retention of hardware for 3 months, but not 6 months, postdiagnosis increases the likelihood of treatment success. The organisms implicated in the infection directly impact the likelihood of treatment success.