Sat., 10/16/10 Polytrauma & Femur, Paper #73, 11:09 am OTA-2010
The Fate of Patients with a ‘Surprise’ Positive Culture after Nonunion Surgery
Paul Tornetta, III, MD1; Dana Olszewski, MD1; Clifford B. Jones, MD2; Martin Hoffmann, MD2;
Debra L. Sietsema, PhD2; Charlton Stucken, MD1; William R. Creevy, MD1;
William M. Ricci, MD3; Michael J. Gardner, MD3; Phillipp N. Streubel, MD3;
1Boston University Medical Center, Boston, Massachusetts, USA;
2Orthopaedic Associates of Michigan, Grand Rapids, Michigan, USA;
3Washington University Medical Center, St. Louis, Missouri, USA
Introduction: Patients who had prior surgery and undergo surgery for a nonunion typically have cultures sent at the time of definitive treatment. A positive culture result that comes back after the procedure is done may represent indolent infection and presents a challenge in treatment. The purpose of this study is to review a series of patients who had a “surprise” positive culture result from definitive surgery for nonunion with regard to postoperative treatment and ultimate result.
Materials: All patients treated for nonunion at 3 Level 1 trauma centers who were considered at risk for indolent infection and had cultures taken at the time of definitive nonunion surgery were evaluated. The course of the patients with a “surprise” positive culture result was documented, including the use of antibiotics, surgery performed, and the outcome regarding infection and union.
Results: Of 666 consecutive nonunions, 456 (68%) had cultures sent at the time of definitive surgical management. This was for a history of prior surgery or open fracture. 94 (21%) had a “surprise” positive culture. The definitive procedures were intramedullary nail (45), open reduction and internal fixation (42), external fixation (1), and bone graft alone (6). 45 (52%) of the patients who had internal stabilization also had local augmentation with graft and/or bone morphogenetic protein. The bacteria isolated from the cultures were: coagulase- negative staphylococcus (45), Staphylococcus aureus (unspecified) (3), S. epidermidis (1), enterococcus (2), pseudomonas (8), bacillus (4), peptostreptococcus (3), methicillin-resistant S. aureus (MRSA) (12), methicillin-sensitive S. aureus (MSSA) (7), Propionobacter (6), strep viridans (2), beta hemolytic streptococcus (1), Serratia marcescens (1), Clostridium tertium (2), Aspergillus (1), and Escherichia coli (1). Seven of the patients had multiple organisms. Infectious disease consultants were involved in all cases. Eight cultures were considered probable contaminants and no additional antibiotics were given. The other 86 patients were treated with 6 to 8 weeks of culture specific antibiotics (77) or with a slightly shorter duration (9). Of the 8 patients with presumed contaminants, 5 have healed and 3 have a persistent nonunion, of which 2 are infected and 1 was amputated. Of the 86 treated with antibiotics, 79 (92%) healed, 5 (6%) developed a recurrent nonunion, and 2 (2%) became grossly infected. Ultimately, 12 (15%) of the 79 who healed had their hardware removed after union. 94% of patients who had augmentation healed as compared with 93% of those not grafted. 2% of those grafted and 2% without grafting developed an infection.
Discussion: The treatment of nonunions is challenging, and in patients with a history of prior surgery or open fracture, we found that 21% had positive intraoperative cultures from the definitive surgery. All but those felt to be contaminants were treated with antibiotics, leading to a postreconstruction infection rate of 2.2%, all with the same organisms cultured at the definitive procedure. Infection was not more common after grafting than if fixation was performed without grafting (such as exchange nailing). The use of culture-specific antibiotics seems justified based on the overall low rate of infection in this complex patient population. This is further supported by 2 of 8 (25%) of those treated as contaminants resulting in infection. Patients may be counseled that a positive culture after nonunion surgery is largely a treatable problem, but that hardware removal may be recommended (15% in this series).
Alphabetical Disclosure Listing (292K PDF)
• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.