title: The reason why orthopaedic surgeons perform total knee replacement: results of a randomised study using case vignettes.
abstract: OBJECTIVE
  End-stage knee osteoarthritis (OA) results in total knee arthroplasty (TKA) surgery. The decision to perform TKA is not well defined, resulting in variation of indications among orthopaedic surgeons. Non-operative treatment measures are often not extensively used. Aim of this study was to investigate factors influencing the decision to perform TKA by Dutch orthopaedic surgeons.
  
  
  METHODS
  Three case vignettes, each case divided into two versions, being identical except for information on age (younger and older age), pain (mild and severe pain) or radiological OA (low and high grade) were developed. A questionnaire including these three case vignettes was sent to 599 Dutch orthopaedic surgeons, who were randomised to either one of the two versions. The orthopaedic surgeons were asked whether TKA would be the next step in treatment. Furthermore, from a list of patient factors they were asked how strong these factors would influence the decision to perform TKA.
  
  
  RESULTS
  54 % of the orthopaedic surgeons completed the questionnaire (n = 326). Orthopaedic surgeons indicated to perform TKA significantly more often at higher age (73.3 vs. 45.5 %, p < 0.001). In the presence of mild pain, orthopaedic surgeons were slightly more reluctant to perform a TKA compared to severe pain (57.0 vs. 64.0 %, n.s.). Mild radiological OA made surgeons more reluctant to perform TKA compared to severe OA (9.7 vs. 96.9 %, p < 0.001).
  
  
  CONCLUSIONS
  Old age and severe radiological OA are variables which are considered to be important in the decision to perform a TKA. Pain symptoms of moderate or severe pain are unequivocal when considering a TKA.
  
  
  METHODS
  Economic/decision analysis, Level III.
authors.affiliation: Department of Orthopaedic Surgery, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands. w.c.verra@lumc.nl.
authors.forename: W C
authors.initials: WC
authors.lastname: Verra
authors.affiliation: Department of Orthopaedic Surgery, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands.
authors.forename: K Q
authors.initials: KQ
authors.lastname: Witteveen
authors.affiliation: Section of Gerontology and Geriatrics, Department of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: A B
authors.initials: AB
authors.lastname: Maier
authors.affiliation: Department of Orthopaedic Surgery, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands.|Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: M G J
authors.initials: MG
authors.lastname: Gademan
authors.affiliation: Department of Orthopaedic Surgery, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands.
authors.forename: H M J
authors.initials: HM
authors.lastname: van der Linden
authors.affiliation: Department of Orthopaedic Surgery, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands.
authors.forename: R G H H
authors.initials: RG
authors.lastname: Nelissen
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D000066491:Clinical Decision-Making; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000072161:Orthopedic Surgeons; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D010146:Pain / Q000175:diagnosis; D010818:Practice Patterns, Physicians'; D011859:Radiography; D011795:Surveys and Questionnaires
keywords: Age; Indication; Osteoarthritis; Pain; Total knee replacement