title: Risk factors for early revision after primary TKA in Medicare patients.
abstract: BACKGROUND
  Patient, surgeon, health system, and device factors are all known to influence outcomes in total knee arthroplasty (TKA). However, patient-related factors associated with an increased risk of early failure are not well understood, particularly in elderly patients.
  
  
  OBJECTIVE
  The purpose of this study was to identify specific comorbid conditions associated with increased risk of early revision in Medicare patients undergoing TKA.
  
  
  METHODS
  A total of 117,903 Medicare patients who underwent primary TKA between 1998 and 2010 were identified from the Medicare 5% national sample administrative database and used to determine the relative risk of revision within 12 months after primary TKA as a function of baseline medical comorbidities. Cox regression was used to evaluate the impact of 29 comorbid conditions on risk of early failure controlling for age, sex, race, census region, socioeconomic status, and all other baseline comorbidities.
  
  
  RESULTS
  The most significant independent risk factors for revision TKA within 12 months were chronic pulmonary disease, depression, alcohol abuse, drug abuse, renal disease, hemiplegia or paraplegia, and obesity.
  
  
  CONCLUSIONS
  This information could be valuable to patients and their surgeons when making shared medical decisions regarding elective TKA and for risk-stratifying publicly reported outcomes in Medicare patients undergoing TKA.
authors: Department of Orthopaedic Surgery, University of California, San Francisco, 500 Parnassus MU 320W, San Francisco, CA, 94143-0728, USA, kevin.bozic@ucsf.edu.
authors: Kevin J
authors: KJ
authors: Bozic
authors: Edmund
authors: E
authors: Lau
authors: Kevin
authors: K
authors: Ong
authors: Vanessa
authors: V
authors: Chan
authors: Steven
authors: S
authors: Kurtz
authors: Thomas P
authors: TP
authors: Vail
authors: Harry E
authors: HE
authors: Rubash
authors: Daniel J
authors: DJ
authors: Berry
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D006278:Medicare; D012086:Reoperation; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014481:United States
references: J Arthroplasty. 2006 Apr;21(3):358-61
references: 16627143
references: Clin Orthop Relat Res. 2008 Jul;466(7):1710-5
references: 18421542
references: Clin Orthop Relat Res. 2010 Nov;468(11):3070-6
references: 20499292
references: Clin Orthop Relat Res. 2010 Jan;468(1):45-51
references: 19554385
references: J Chronic Dis. 1987;40(5):373-83
references: 3558716
references: Clin Orthop Relat Res. 2012 Jan;470(1):130-7
references: 21874391
references: J Bone Joint Surg Am. 2006 Jul;88(7):1425-30
references: 16818966
references: Med Care. 1998 May;36(5):661-9
references: 9596057
references: J Bone Joint Surg Am. 2001 Oct;83(10):1582-5
references: 11679613
references: Clin Orthop Relat Res. 2013 Jan;471(1):201-5
references: 22528384
references: Med Care. 1998 Jan;36(1):8-27
references: 9431328
references: Clin Orthop Relat Res. 2010 Aug;468(8):2052-9
references: 20309657
references: N Engl J Med. 2012 Jul 26;367(4):292-5
references: 22830460
references: J Bone Joint Surg Am. 2007 Oct;89 Suppl 3:144-51
references: 17908880
references: Clin Orthop Relat Res. 2007 Nov;464:83-7
references: 17589362
references: N Engl J Med. 1990 Sep 13;323(11):725-31
references: 2201916
references: Fed Regist. 2011 Nov 30;76(230):74122-584
references: 22145188
references: Clin Orthop Relat Res. 2006 May;446:15-21
references: 16672866
references: J Arthroplasty. 2012 Oct;27(9):1690-1695.e1
references: 22633104
references: J Bone Joint Surg Br. 2012 Aug;94(8):1058-66
references: 22844046
references: JAMA. 2012 Aug 8;308(6):577-8
references: 22871868