The Influence of an Occult Infection on the Outcome of Autologous Bone Grafting During Surgical Bone Reconstruction: A Large Single-Center Case-Control Study

Abstract

Michael C Tanner,1 Raban Arved Heller,1– 3 Andreas Grimm,1 Stefan Zimmermann,4 Maximilian Pilz,5 Louisa Jurytko,1 Matthias Miska,1 Lars Helbig,1 Gerhard Schmidmaier,1 Patrick Haubruck1,6 1HTRG – Heidelberg Trauma Research Group, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Trauma and Reconstructive Surgery, Heidelberg University Hospital, Heidelberg, D-69118, Germany; 2Institute for Experimental Endocrinology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt Universität Zu Berlin, Berlin Institute of Health, Berlin, D-13353, Germany; 3Department of General Practice and Health Services Research, Heidelberg University Hospital, Heidelberg, D-69120, Germany; 4Division Bacteriology, Department of Infectious Diseases, Heidelberg University Hospital, Heidelberg, D-69120, Germany; 5Institute of Medical Biometry and Informatics, Heidelberg University Hospital, Heidelberg, D-69120, Germany; 6Raymond Purves Bone and Joint Research Laboratory, Institute of Bone and Joint Research, Kolling Institute, Royal North Shore Hospital, University of Sydney, St. Leonards, New South Wales, A-2068, AustraliaCorrespondence: Patrick HaubruckRaymond Purves Bone and Joint Research Laboratory, Institute of Bone and Joint Research, Kolling Institute, Royal North Shore Hospital, University of Sydney, St Leonards, NSW, A-2068, AustraliaTel [phone]Email [email protected]: Occult infections (OI) lack typical inflammatory signs, making them challenging to diagnose. Uncertainty remains regarding OI’s influence on the outcome of autologous bone grafting (ABG), and evidence-based recommendations regarding an appropriate course of action are missing. Thus, we sought to determine the incidence of an OI in patients receiving ABG, evaluate whether it influences the outcome of ABG and whether associated risk factors have a further negative influence.Methods: This study was designed as a large size single-center case-control study investigating patients treated between 01/01/2010 and 31/12/2016 with a minimum follow-up of 12 months. Patients ≥ 18 years presenting with a recalcitrant non-union of the lower limb receiving surgical bone reconstruction, including bone grafting, were included. A total of 625 patients were recruited, and 509 patients included in the current study. All patients received surgical non-union therapy based on the “diamond concept” including bone reconstruction using ABG. Additionally, multiple tissue samples were harvested and microbiologically analyzed. Tissue samples were microbiologically evaluated regarding an OI. Bone healing was analyzed using clinical and radiological parameters, patient characteristics and comorbidities investigated and ultimately results correlated.Results: Forty-six out of 509 cases with OI resulted in an incidence of 9.04%. Overall consolidation time was increased by 15.08 weeks and radiological outcome slightly impaired (79.38% vs 71.42%), differences were at a non-significant extent. Diabetes mellitus had a significant negative influence on consolidation time (p=0.0313), while age (p=0.0339), smoking status (p=0.0337), diabetes mellitus (p=0.0400) and increased BMI (p=0.0315) showed a significant negative influence on the outcome of bone grafting.Conclusion: Surgeons treating recalcitrant non-unions should be aware that an OI is common. If an OI is diagnosed subsequent to ABG the majority of patients does not need immediate revision surgery. However, special attention needs to be paid to high-risk patients.Keywords: infection, bone healing, bone regeneration, non-union, bone infection

Keywords

• infection
• bone healing
• bone regeneration
• non-union
• bone infection