Research Article| Volume 136, P14-19, June 2023

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Bone flap infections after craniotomy: a review of 63 cases and the implications for definitions, classification and surveillance methodologies

Published:March 31, 2023DOI:



      Bone flap infections (BFIs) occur following neurosurgical procedures such as craniotomies. However, they are poorly defined and often not clearly differentiated from other surgical site infection in neurosurgery.


      To review data from a national adult neurosurgical centre to explore some clinical aspects to better inform definitions, classification and surveillance methodologies.


      We retrospectively reviewed data on clinical samples sent for culture from patients with suspected BFI. We also accessed information recorded prospectively from national and local databases for evidence of BFI or related conditions based on terms used in surgical operative notes or discharge summaries and documented monomicrobial and polymicrobial infections related to craniotomy sites.


      Between January 2016 and December 2020, we documented 63 patients with a mean age of 45 years (16–80). Craniectomy for infection of the skull was the most common terminology used to describe BFI in the coding used in a national database, 40/63 (63%), but other terms were used. A malignant neoplasm was the most common underlying condition necessitating craniectomy in 28/63 (44%) cases. Specimens submitted for microbiological investigation included 48/63 (76%) bone flaps, 38/63 (60%) fluid/pus, and 29/63 (46%) tissue. Fifty-eight (92%) patients had at least one culture-positive specimen; 32 (55%) were monomicrobial and 26 (45%) were polymicrobial. Gram-positive bacteria predominated and Staphylococcus aureus was the most common.


      Greater clarity on how to define BFI is required to enable better classification and the carrying out of appropriate surveillance. This will inform preventative strategies and more effective patient management.


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        • Kolpa M.
        • Walaszek M.
        • Różańska A.
        • Wolak Z.
        • Wójkowskám-Mach J.
        Hospital-wide surveillance of healthcare-associated infections as a source of information about specific hospital needs. A 5-year observation in a multi-profile provincial hospital in the South of Poland.
        Int J Environ Res Pub Health. 2018; 15: 1956
        • Pérez C.D.-A.
        • López-Fresneňa N.
        • Carlavilla A.L.R.
        • Garcia M.H.
        • Ruiz-Garbajosa P.
        • Aranaz-Andrés J.M.
        • et al.
        Local presence of extended-spectrum β-lactamase (ESBL), producing Enterobacteraciae intestinal carriers at admission and co-expression of ESBL and OXA-48 carbapenemase in Klebsiella pneumoniae: a prevalence survey in a Spanish university hospital.
        BMJ Open. 2019; 9e024879
        • Wong J.L.C.
        • Ho C.W.I.
        • Scott G.
        • Machin J.T.
        • Briggs T.W.R.
        The National Surgical Site infection Audit Collaborators. Getting it right first time: the national survey of surgical site infection rates in NHS Trusts in England.
        Am R Coll Surg Engl. 2019; 101: 463-471
        • Hamdeh S.A.
        • Lytsy B.
        • Ronne-Engström E.
        Surgical site infections in standard neurosurgery procedures – a study of incidence, impact and potential risk factors.
        Br J Neurosurg. 2014; 28: 270-275
        • Pereira P.L.
        • Pérez C.D.-A.
        • Fresneňa N.L.
        • Mosteiro J.L.H.
        • Cabrera A.P.
        • Carlavilla A.L.R.
        • et al.
        Epidemiology of surgical site infection in a neurosurgery department.
        Br J Neurosurg. 2017; 31: 10-15
        • Han C.
        • Song Q.
        • Ren Y.
        • Luo J.
        • Jiang X.
        • Hu D.
        Dose–response association of operative time and surgical site infection in neurosurgery patients: a systematic review and meta-analysis.
        Am J Infect Control. 2019; 47: 1393-1396
        • Jiménez-Martínez E.
        • Cuervo G.
        • Hornero A.
        • Ciercoles P.
        • Gabarrós A.
        • Cabellos C.
        • et al.
        Risk factors for surgical site infection after craniotomy: a perspective cohort study.
        Antimicrob Res Infect Control. 2019; 8: 69
        • Shepetovsky D.
        • Mezzini G.
        • Magrassi L.
        Complications of cranioplasty in relationship to traumatic brain injury: a systematic review and meta-analysis.
        Neurosurg Rev. 2021; 44: 3125-3142
        • Henry J.
        • Amoo M.
        • Murphy A.
        • O’Brien D.P.
        Complications of cranioplasty following decompressive craniectomy for traumatic brain injury: systematic review and meta-analysis.
        Acta Neurochir. 2021; 163: 1423-1435
        • Goedemans T.
        • Verbaan D.
        • van der Veer O.
        • Bot M.
        • Post R.
        • Hoogmoed J.
        • et al.
        Complications in cranioplasty after decompressive craniectomy: timing of the intervention.
        J Neurolog. 2020; 267: 1312-1320
        • Ortiz Torres M.
        • Ziu E.
        • Agunbiade S.
        • Carr S.B.
        • Litofsky N.S.
        Bifrontal osteoplastic flap: an option to decrease infection in bifrontal craniotomies with skull base osteotomies.
        Brain Sci. 2022; 12: 163
        • Skally M.
        • Finn C.
        • O’Brien D.
        • Fitzpatrick F.
        • Burns K.
        • McFadden E.
        • et al.
        Invasive MRSA infections in neurosurgical patients – a decade of progress.
        Br J Neurosurg. 2017; 31: 374-378
        • Creedon M.
        • Humphreys S.
        • Connolly R.
        • Gaughan L.
        • Caird J.
        • Duddy J.
        • et al.
        Multi-disciplinary neurosurgical rounds incorporating antimicrobials stewardship. Are they of benefit?.
        Brain Spine. 2022; 100885
        • Chiang H.-Y.
        • Kamath A.
        • Pottinger J.M.
        • Greenlee J.D.W.
        • Howard III, M.A.
        • Cavanaugh J.E.
        • et al.
        Risk factors and outcomes associated with surgical site infections after craniotomy or craniectomy.
        J Neurosurg. 2014; 120: 509-521
        • Shafiei M.
        • Sourani A.
        • Saboori M.
        • Aminmansour B.
        • Mahram S.
        Comparison of subcutaneous pocket with cryopreservation method for storing for storing autologous bone flaps in developing surgical wound infection after cranioplasty; a randomised clinical trial.
        J Clin Neurosci. 2021; 91: 136-143
        • Bhaskar I.P.
        • Zaw N.N.
        • Zheng M.
        • Lee G.Y.
        Bone flap storage following craniectomy: a survey of practices in major Australian neurosurgical centres.
        ANZ J Surg. 2011; 81: 137-141
        • Chiang H.Y.
        • Steelman V.M.
        • Pottinger J.M.
        • Schlueter A.J.
        • Diekema D.J.
        • Greenlee J.D.
        • et al.
        Clinical significance of positive cranial bone flap cultures and associated risk of surgical site infection after craniotomies or craniectomies.
        J Neurosurg. 2011 Jun; 114: 1746-1754