title: Cerebral fat microembolism and cognitive decline after hip and knee replacement.
abstract: OBJECTIVE
  Intra-operative cerebral microembolism may be a factor in the etiology of cognitive decline after orthopedic surgery. We here examine the impact of intra-operative microembolism on cognitive dysfunction after hip and knee replacement surgery.
  
  
  METHODS
  We enrolled 24 patients, at least 65 years old, requiring elective knee or hip replacement surgery. A transcranial Doppler shunt study was done to determine study eligibility so that the final study population consisted of 12 consecutive patients with and 12 consecutive patients without a venous-arterial shunt. A standard neuropsychological test battery was administered before surgery, at hospital discharge and 3 months after surgery. All patients were monitored intra-operatively for microemboli. Quality of life data were assessed at 1 year.
  
  
  RESULTS
  The mean age of patients was 74 years. All patients had intra-operative microemboli. The mean number of emboli was 9.9+/-18. Cognitive decline was present in 18/22 (75%) at discharge and in 10/22 (45%) at 3 months, despite improved quality of life measures. There was no correlation between cognitive decline and intra-operative microembolism.
  
  
  CONCLUSIONS
  Cognitive decline was seen frequently after hip and knee surgery. Intra-operative microembolism occurred universally but did not significantly influence postoperative cognition. Quality of life and functional outcome demonstrated improvement in all cases in spite of cognitive dysfunction.
authors.affiliation: Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL, USA. skoch@med.miami.edu
authors.forename: Sebastian
authors.initials: S
authors.lastname: Koch
authors.forename: Alejandro
authors.initials: A
authors.lastname: Forteza
authors.forename: Carlos
authors.initials: C
authors.lastname: Lavernia
authors.forename: Jose G
authors.initials: JG
authors.lastname: Romano
authors.forename: Iszet
authors.initials: I
authors.lastname: Campo-Bustillo
authors.forename: Nelly
authors.initials: N
authors.lastname: Campo
authors.forename: Stuart
authors.initials: S
authors.lastname: Gold
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D003072:Cognition Disorders / Q000209:etiology / Q000523:psychology*; D004620:Embolism, Fat / Q000209:etiology / Q000523:psychology*; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000209:etiology / Q000523:psychology*; D007431:Intraoperative Complications / Q000523:psychology; D008297:Male