title: Do smokers have greater risk of delayed and non-union after fracture, osteotomy and arthrodesis? A systematic review with meta-analysis.
abstract: Systematic review and meta-analysis of published observational cohort studies. To quantify the increased risk smokers have of experiencing a delayed and/or non-union in fractures, spinal fusion, osteotomy, arthrodesis or established non-unions.
  
  
  
  Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (EMBASE), Allied and Complementary Medicine Database (AMED) and Web of Science Core Collection from 1966 to 2015.
  
  
  
  Observational cohort studies that reported adult smokers and non-smokers with delayed and/or non-union or time to union of the fracture, spinal fusion, osteotomy, arthrodesis or established non-union were eligible.
  
  
  
  2 authors screen titles, abstracts and full papers. Data were extracted by 1 author and checked independently by a second. The relative risk ratios of smoking versus non-smoking and the mean difference in time to union patients developing a delayed and/or non-union were calculated.
  
  
  
  The search identified 3013 articles; of which, 40 studies were included. The meta-analysis of 7516 procedures revealed that smoking is linked to an increased risk of delayed and/or non-union. When considered collectively, smokers have 2.2 (1.9 to 2.6) times the risk of experiencing delayed and/or non-union. In all the subgroups, the increased risk was always ≥1.6 times that of non-smokers. In the patients where union did occur, it was a longer process in the smokers. The data from 923 procedures were included and revealed an increase in time to union of 27.7 days (14.2 to 41.3).
  
  
  
  Smokers have twice the risk of experiencing a non-union after fracture, spinal fusion, osteotomy, arthrodesis or treatment of non-union. Time to union following fracture, osteotomy, arthrodesis or treatment of an established non-union is longer in smokers. Smokers should be encouraged to abstain from smoking to improve the outcome of these orthopaedic treatments.
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, UK.
authors.forename: R G
authors.initials: RG
authors.lastname: Pearson
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, UK.
authors.forename: R G E
authors.initials: RG
authors.lastname: Clement
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, UK.
authors.forename: K L
authors.initials: KL
authors.lastname: Edwards
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, UK.
authors.forename: B E
authors.initials: BE
authors.lastname: Scammell
mesh_terms: D001174:Arthrodesis; D017102:Fracture Healing / Q000276:immunology; D050723:Fractures, Bone / Q000503:physiopathology*; D017759:Fractures, Malunited / Q000503:physiopathology; D005599:Fractures, Ununited / Q000503:physiopathology; D006801:Humans; D010027:Osteotomy; D011183:Postoperative Complications / Q000276:immunology / Q000503:physiopathology*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000276:immunology / Q000503:physiopathology; D013530:Surgical Wound Infection / Q000276:immunology / Q000503:physiopathology*
keywords: Delayed-uion; Fracture; Non-union; Smoking; meta-analysis