Bacterial osteomyelitis: microbiological, clinical, therapeutic, and evolutive characteristics of 344 episodes

Osteomyelitis is a difficult-to-cure infection, with high relapse rate despite adequate therapy. Large published osteomyelitis series in adults are rare. A total of 344 adult osteomyelitis patients were studied and followed > 12 months after hospital discharge. Demographic, microbiological, clinical, therapeutic and outcome data were analyzed. Mean age was 52.5 ± 18.3 years and 233 (67.7%) were male. Main osteomyelitis types were post-surgical (31.1%), post-traumatic (26.2%) and hematogenous (23%). Tibia (24.1%) and femur (21.8%), and methicillin-susceptible S. aureus (29.6%) were the most commonly involved bone and bacteria, respectively. Median follow-up was 12.0 (IQR 0-48) months. Inflammatory markers were increased in 73.6%. Overall, patients were treated by IV and oral routes with one (IV: 44.5%, oral: 26.7%), two (IV: 30.1%, oral: 21.8%) or ≥ 2 (IV: 15.2%, oral: 6.1%) antibiotics. Median duration on IV/oral antimicrobials was 28.0 (IQR 24-28) and 19.5 (IQR 4-56) days, respectively. Anti-staphylococcal β-lactams cloxacillin/cefazolin (19.2%) and ciprofloxacin (5.5%) were the most frequently used IV and orally, respectively. Overall 234 (68.0%) underwent surgery, 113 (32.8%) debridement, 97 (27.4%) debridement + muscle flap and 24 (7%) amputation. At the end of follow-up 208 patients (60.6%) did not have relapsed. Operated patients had significantly less relapses (p