Osteocutaneous-flap-related osteomyelitis following mandibular reconstruction: a cohort study of an emerging and complex bone infection

Osteocutaneous flap (OCF) mandible reconstruction is at high risk for surgical site infection. This study aimed to describe diagnosis, management, and outcome of OCF-related osteomyelitis. All patients managed at our institution for an OCF-related osteomyelitis following mandible reconstruction were included in a retrospective cohort study (2012–2019). Microbiology was described according to gold-standard surgical samples, considering all virulent pathogens, and potential contaminants if present on at least two samples. Determinants of treatment failure were assessed by logistic regression and Kaplan–Meier curve analysis. The 48 included patients (median age 60.5 (IQR, 52.4–66.6) years) benefited from OCF mandible reconstruction mostly for carcinoma ( [Formula: see text] ; 56.3 %) or osteoradionecrosis ( [Formula: see text] ; 25.0 %). OCF-related osteomyelitis was mostly early ( [Formula: see text] months post-surgery; [Formula: see text] ; 89.6 %), presenting with local inflammation ( [Formula: see text] ; 59.6 %), nonunion (wound dehiscence) or sinus tract ( [Formula: see text] ; 59.6 %), and/or bone or device exposure ( [Formula: see text] ; 44.7 %). Main implicated pathogens were Enterobacteriaceae ( [Formula: see text] ; 61.0 %), streptococci ( [Formula: see text] ; 53.7 %), Staphylococcus aureus ( [Formula: see text] ; 24.4 %), enterococci ( [Formula: see text] ; 22.0 %), non-fermenting Gram-negative bacilli ( [Formula: see text] ; 19.5 %), and anaerobes ( [Formula: see text] ; 19.5 %). Thirty-nine patients (81.3 %) benefited from surgery, consisting of debridement with implant retention (DAIR) in [Formula: see text] (64.1 %) cases, associated with 93 (IQR, 64–128) days of antimicrobial therapy. After a follow-up of 18 (IQR, 11–31) months, [Formula: see text] (50.0 %) treatment failures were observed. Determinants of treatment outcomes were DAIR (OR, 3.333; 95 % CI, 1.020–10.898) and an early infectious disease specialist referral (OR, 0.236 if [Formula: see text] weeks; 95 % CI, 0.062–0.933). OCF-related osteomyelitis following mandibular reconstruction represents difficult-to-treat infections. Our results advocate for a multidisciplinary management, including an early infectious-disease-specialist referral to manage the antimicrobial therapy driven by complex microbiological documentation.