title: Is potential malnutrition associated with septic failure and acute infection after revision total joint arthroplasty?
abstract: BACKGROUND
  Although malnutrition has been hypothesized to increase the risk of periprosthetic joint infection (PJI), strong evidence linking the two is lacking.
  
  
  OBJECTIVE
  The purposes of this study were to determine (1) if one or more laboratory values suggestive of malnutrition is independently associated with being revised for an infected joint arthroplasty as opposed to for an aseptic failure; (2) the relationship between laboratory parameters suggestive of malnutrition and obesity; and (3) if one or more laboratory parameters suggestive of malnutrition is independently associated with acute PJI complicating an aseptic revision procedure.
  
  
  METHODS
  Between 2002 and 2010, one surgeon performed 600 revision total joint arthroplasties in 547 patients; during that time, nutritional parameters (including serum albumin, total lymphocyte count, and transferrin) were routinely obtained preoperatively; complete data sets were available on 454 patients (501 procedures [84%]). We compared the frequency of having one or more laboratory parameters suggestive of malnutrition between patients undergoing a revision for septic reasons and aseptic reasons as well as between obese and nonobese patients. The 375 aseptic revisions were then assessed for the incidence of acute postoperative infection (within 90 days, diagnosed with Musculoskeletal Infection Society criteria). Multivariate logistic regression modeling was used to evaluate factors independently associated with (1) a septic as opposed to an aseptic mode of failure; and (2) acute postoperative infection after an aseptic revision.
  
  
  RESULTS
  Patients in 67 of 126 (53%) revisions for PJI had one or more laboratory parameters suggestive of malnutrition compared with 123 of 375 (33%) undergoing revision for a noninfectious etiology (odds ratio [OR], 2.3 [95% confidence interval, 1.5-3.5]; p<0.001). Patients who were of normal weight at the time of revision had the highest frequency of laboratory parameters suggestive of malnutrition (42 of 82 [51%]), although this was common in obese patients as well (76 of 238 [32%]) (p=0.002). Among the 375 aseptic revisions, 12 developed an acute postoperative infection (3%). The frequency of infection was nine of 123 in the group having one or more laboratory parameters suggestive of malnutrition and three of 252 in the group not having such laboratory parameters (7% versus 1%; p=0.003). Multivariate regression revealed that having laboratory parameters suggestive of malnutrition is independently associated with both chronic PJI (p=0.003; OR, 2.1) and an acute postoperative infection complicating an aseptic revision arthroplasty (p=0.02; OR, 5.9).
  
  
  CONCLUSIONS
  Having one or more laboratory parameters suggestive of malnutrition is common among patients undergoing revision arthroplasty and is independently associated with both chronic septic failure and acute postoperative infection complicating a revision performed for a noninfectious etiology. Future studies should assess the impact of a standardized screening protocol with subsequent correction of abnormal laboratory parameters suggestive of malnutrition on the risk of PJI to determine a potential causal relationship between the two.
  
  
  METHODS
  Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Midwest Orthopaedics at Rush University Medical Center, 1611 W Harrison Street, Suite 300, Chicago, IL, 60612, USA.
authors.forename: Paul H
authors.initials: PH
authors.lastname: Yi
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Frank
authors.forename: Elliott
authors.initials: E
authors.lastname: Vann
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Sonn
authors.forename: Mario
authors.initials: M
authors.lastname: Moric
authors.forename: Craig J
authors.initials: CJ
authors.lastname: Della Valle
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement / Q000009:adverse effects* / Q000295:instrumentation*; D005260:Female; D006801:Humans; D007595:Joint Prosthesis / Q000009:adverse effects*; D016015:Logistic Models; D008297:Male; D044342:Malnutrition / Q000150:complications* / Q000175:diagnosis; D008875:Middle Aged; D015999:Multivariate Analysis; D015596:Nutrition Assessment; D009752:Nutritional Status; D016017:Odds Ratio; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000175:diagnosis / Q000209:etiology* / Q000382:microbiology / Q000503:physiopathology; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D018805:Sepsis / Q000175:diagnosis / Q000209:etiology* / Q000382:microbiology / Q000503:physiopathology; D013997:Time Factors