Surgical site infection after surgery to repair femoral neck fracture: a French multicenter retrospective study

Abstract

Objective: Femoral neck fracture is the most frequent orthopedic emergency among elderly persons. Despite a high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage in this population, no multicenter study of antibiotic prophylaxis practices and the rate and microbiological characteristics of surgical site infection (SSI) has been performed in France.

Design: Retrospective, multicenter cohort study.

Setting: Twenty-two university and community hospitals in France.

Patients: Each center provided data on 25 consecutive patients who underwent surgery for femoral neck fracture during the first quarter of 2005. Demographic, clinical, and follow-up characteristics were recorded, and most patients had a follow-up office visit or were involved in a telephone survey 1 year after surgery.

Results: These 22 centers provided data on 541 patients, 396 (73%) of whom were followed up 1 year after surgery. Of 504 (93%) patients for whom antibiotic prophylaxis was recorded, 433 (86%) received a cephalosporin. Twenty-two patients had an SSI, for a rate of 5.6% (95% confidence interval, 3.7-8.0). SSI was reported for 15 (6.9%) of patients who had a prosthesis placed and for 7 (3.9%) who underwent osteosynthesis (P=.27). SSI was diagnosed a median of 30 days after surgery (interquartile range, 21-41 days); 7 (32%) of these SSIs were superficial infections, and 15 (68%) were deep or organ-space infections. MRSA caused 7 SSIs (32%), Pseudomonas aeruginosa caused 5 (23%), other staphylococci caused 4 (18%), and other bacteria caused 2 (9%); the etiologic pathogen was unknown in 4 cases (18%). Reoperation was performed for 14 patients with deep or organ-space SSI, including 6 of 7 patients with MRSA SSI. The mortality rate 1 year after surgery was 20% overall but 50% among patients with SSI. In univariate analysis, only the National Nosocomial Infections Surveillance System risk index score was significantly associated with SSI (P=.006).

Conclusions: SSI after surgery for femoral neck fracture is severe, and MRSA is the most frequently encountered etiologic pathogen. A large, multicenter prospective trial is necessary to determine whether the use of antibiotic prophylaxis effective against MRSA would decrease the SSI rate in this population.