Current bacterial speciation and antibiotic resistance in deep infections after operative fixation of fractures

Infection after fracture fixation is a major source of morbidity. Information regarding bacterial speciation and antibiotic resistance is lacking. We attempted to determine the speciation and drug resistance profiles associated with fracture fixation infections.

Retrospective study.

Level I trauma center.

Two hundred eleven patients with 214 infections underwent surgery for postoperative infection from December 2006 to December 2010. Deep postoperative infections within 12 months of fixation were included.

None.

Incidence of each bacterial species and rate of clinically relevant resistance in Staphylococcus aureus, gram-negative rod (GNR), and Enterococcus species. The effect of timing of infection presentation and location of fracture on bacterial speciation was also investigated.

Fifty-six percent of infections had S. aureus present, with 58% of those (32% of all infections) being methicillin-resistant S. aureus. Thirty-two percent of infections had at least one GNR present, with only 4% of those being multidrug resistant. We found a marked increase in the rate of GNR infections of the pelvis, acetabulum, and proximal femur (63%) compared with other locations (27%), which was statistically significant (P = 0.0002).

At our center, S. aureus and GNR are most often found in deep postoperative infections after fixation. Methicillin-resistant S. aureus is common in this population. Our GNR rate is high, but resistance in this group was low. The proportion of GNR infections in the pelvis, acetabulum, and proximal femur was high even in closed fractures. These data provide a modern snapshot of orthopaedic infections after fracture fixation and might be useful in designing future studies and protocols for antibiotic prophylactic treatment. We are considering the use of aminoglycosides in the treatment of closed fractures of the pelvis, acetabulum, and proximal femur.

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.