PO vs IV Antibiotics for the Treatment of Infected Nonunion of Fractures After Fixation

This is a Phase III clinical randomized control trial to investigate differences between patient with an infected nonunion treated by PO vs. IV antibiotics. The study population will be 250 patients, 18 years or older, being treated for infected nonunion after internal fixation of a fracture with a segmental defect less than one centimeter. Patients will be randomly assigned to either the treatment (group 1) PO antibiotics for 6 weeks or the control group (group 2) IV antibiotics for 6 weeks. The primary hypothesis is that the effectiveness of oral antibiotic therapy is equivalent to traditional intravenous antibiotic therapy for the treatment of infected nonunion after fracture internal fixation, when such therapy is combined with appropriate surgical management. Clinical effectiveness will be measured as the primary outcome as the number of secondary re-admissions related to injury and secondary outcomes of treatment failure (re-infection, nonunion, antibiotic complications) within the first one year of follow-up, as defined by specified criteria and determined by a blinded data assessment panel. In addition, treatment compliance, the cost of treatment, the number of surgeries required, the type and incidence of complications, and the duration of hospitalization will be measured.

The specific Aims of this study are to:

Specific Aim 1. Evaluate the effect of treatment of infected nonunion in bone fractures treated with revision fixation and either: (Group 1) operative debridement and PO antibiotic suppression for 6 weeks; or (Group 2) operative debridement and 6 weeks IV antibiotics.

Primary Hypothesis 1a: The rate of re-hospitalization for injury-related complication by one year in Group 1 will be non-inferior to the rate in Group 2.

Hypothesis 1b:. The rate of treatment failure by one year in Group 1 will be non-inferior to the rate in Group 2.

Hypothesis 1c: The rate of persistent infection by one year in Group 1 will be non-inferior to the rate in Group 2.

Hypothesis 1d: The rate of persistent nonunion by one year in Group 1 will be non-inferior to the rate in Group 2.

Hypothesis 1e: The rate of amputation by one year in Group 1 will be non-inferior to the rate in Group 2. Hypothesis 1f: Per patient total costs at 1 year will be lower in Group 1 than in Group 2.

Hypothesis 1g: Compliance in Group 1 will be non-inferior to compliance in Group 2.

Specific Aim 2. Build and validate a risk prediction model for failure of treatment of infected nonunion after fixation of fractures.

Hypothesis 2a: Demographic and injury characteristics will be highly predictive of treatment failure.

Hypothesis 2b: Open fractures will have a higher treatment failure rate than closed fractures.

Hypothesis 2c: Lower extremity fractures will have a higher treatment failure rate than upper extremity fractures.

Hypothesis 2d: Multiple organism infections will have a higher treatment failure rate than single organism infections.

Hypothesis 2e: Gram positive infections will have a higher treatment failure rate than gram negative infections.

Hypothesis 2f: Revision fixation with IMN and treatment failure will be non-inferior to the rate of treatment failure in revision fixation with plates.

Hypothesis 2g: Revision fixation with external fixation and treatment failure will be non-inferior to the rate of treatment failure in revision fixation with IMN or plates.

Hypothesis 2h: One Stage revision fixation strategies will be non-inferior to the rate of treatment failure in Two Staged revision fixation strategies

Study design: At time of treatment for infected nonunion, patients will be randomized to oral (PO) antibiotics group or intravenous (IV) antibiotics group. Patients will receive PO or IV antibiotics for 6 weeks at discharge from the hospitalization to treat the infected nonunion. Both groups will otherwise receive standard care treatment by attending orthopedic surgeon and healthcare team, including debridement and soft tissue coverage of wounds; laboratory evaluation of inflammatory markers at 2 weeks, and 6 weeks; clinical follow at 2 weeks, 6 weeks, 3 months, 6 months, and 12 months to assess recurrence of wound infection; and radiographic follow up at 6 weeks and 3 months or until boney union is confirmed.

Follow-Up: Assessments at baseline and at 2 weeks, 6 weeks, 3 months, 6 months and 12 months following hospital discharge will determine rates of re-hospitalization, treatment failure, infection, nonunion and amputation and patient compliance with antibiotic treatment.