title: Patient-reported allergies cause inferior outcomes after total knee arthroplasty.
abstract: OBJECTIVE
  The main objective of this study was to analyse the outcomes after total knee arthroplasty (TKA) of a group of patients with at least one self-reported allergy and a group of patients without reported allergies. We hypothesized there is a significant negative influence on clinical outcome scores after TKA in patients with self-reported allergies.
  
  
  METHODS
  Four-hundred and seventy-five patients who had undergone TKA were analysed preoperatively and 1 year after surgery. The WOMAC, KSS and SF-36 scores were obtained. The patients' Yesavage depression questionnaire score was also recorded. The scores of the 330 (69.5 %) patients without self-reported allergies were compared to the scores of the 145 (30.5 %) patients with at least one self-reported allergy in the medical record.
  
  
  RESULTS
  Preoperative scores were similar in both groups. The WOMAC post-operative scores (23.6 vs 20.4; p = 0.037) and the KSS-Knee score (91.1 vs 87.6; p = 0.027) were worse in the group of patients with self-reported allergies than in the group without allergies. The scores from the Yesavage depression questionnaire and in the SF-36 were similar in both groups.
  
  
  CONCLUSIONS
  Patients with at least one self-reported allergy have worse post-operative outcomes in terms of the WOMAC and KSS-Knee scores after TKA than patients without allergies. These poor outcomes do not seem to be related to depression. Therefore, more research is needed to explain them. Reported allergies could be considered a prognostic factor and used when counselling TKA patients.
  
  
  METHODS
  I.
authors.affiliation: Department of Orthopedic Surgery, Parc de Salut Mar. Hospital de la Esperanza. Universitat Autònoma de Barcelona, Sant Josep de la Muntanya, 12, 08024, Barcelona, Spain. Phinarejos@parcdesalutmar.cat.
authors.forename: Pedro
authors.initials: P
authors.lastname: Hinarejos
authors.affiliation: Department of Orthopedic Surgery, Parc de Salut Mar. Hospital de la Esperanza. Universitat Autònoma de Barcelona, Sant Josep de la Muntanya, 12, 08024, Barcelona, Spain.
authors.forename: Tulia
authors.initials: T
authors.lastname: Ferrer
authors.affiliation: Department of Orthopedic Surgery, Parc de Salut Mar. Hospital de la Esperanza. Universitat Autònoma de Barcelona, Sant Josep de la Muntanya, 12, 08024, Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Leal
authors.affiliation: Department of Orthopedic Surgery, Parc de Salut Mar. Hospital de la Esperanza. Universitat Autònoma de Barcelona, Sant Josep de la Muntanya, 12, 08024, Barcelona, Spain.
authors.forename: Raul
authors.initials: R
authors.lastname: Torres-Claramunt
authors.affiliation: Department of Orthopedic Surgery, Parc de Salut Mar. Hospital de la Esperanza. Universitat Autònoma de Barcelona, Sant Josep de la Muntanya, 12, 08024, Barcelona, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Sánchez-Soler
authors.affiliation: Department of Orthopedic Surgery, Parc de Salut Mar. Hospital de la Esperanza. Universitat Autònoma de Barcelona, Sant Josep de la Muntanya, 12, 08024, Barcelona, Spain.
authors.forename: Joan Carles
authors.initials: JC
authors.lastname: Monllau
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology*; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D063868:Patient Outcome Assessment; D011379:Prognosis; D011446:Prospective Studies; D057566:Self Report; D013030:Spain / Q000453:epidemiology
keywords: Allergies; Depression; KSS; Outcomes; Total knee arthroplasty; WOMAC