title: Mortality and reoperations following lower limb amputations.
abstract: BACKGROUND
  Above-the-knee amputations (AKA) and below-the-knee amputations (BKA) are commonly indicated in patients with ischemia, extensive tissue loss, or infection. AKA were previously reported to have better wound-healing rates but poorer rehabilitation rates than BKA.
  
  
  OBJECTIVE
  To compare the outcomes of AKA and BKA and to identify risk factors for poor outcome following leg amputation.
  
  
  METHODS
  This retrospective cohort study comprised 188 consecutive patients (mean age 72 years, range 25-103, 71 males) who underwent 198 amputations (91 AKA, 107 BK 10 bilateral procedures) between February 2007 and May 2010. Included were male and female adults who underwent amputations for ischemic, infected or gangrenotic foot. Excluded were patients whose surgery was performed for other indications (trauma, tumors). Mortality and reoperations (wound debridement or need for conversion to a higher levelof amputation) were evaluated as outcomes. Patient- and surgery-related risk factors were studied in relation to these primary outcomes.
  
  
  RESULTS
  The risk factors for mortality were dementia [hazard ratio (HR) 2.769], non-ambulatory status preoperatively (HR 2.281), heart failure (HR 2.013) and renal failure (HR 1.87). Resistant bacterial infection (HR 3.083) emerged as a risk factor for reoperation. Neither AKA nor BKA was found to be an independent predictor of mortality or reoperation.
  
  
  CONCLUSIONS
  Both AKA and BKA are associated with very high mortality rates. Mortality is most probably related to serious comorbidities (renal and heart disease) and to reduced functional status and dementia. Resistant bacterial infections are associated with high rates of reoperation. The risk factors identified can aid surgeons and patients to better anticipate and possibly prevent severe complications.
authors.forename: Noam
authors.initials: N
authors.lastname: Rosen
authors.forename: Roy
authors.initials: R
authors.lastname: Gigi
authors.forename: Amir
authors.initials: A
authors.lastname: Haim
authors.forename: Moshe
authors.initials: M
authors.lastname: Salai
authors.forename: Ofir
authors.initials: O
authors.lastname: Chechik
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical / Q000009:adverse effects / Q000379:methods / Q000401:mortality; D015897:Comorbidity; D005260:Female; D005734:Gangrene / Q000453:epidemiology / Q000209:etiology / Q000601:surgery; D006801:Humans; D007511:Ischemia / Q000453:epidemiology / Q000209:etiology / Q000601:surgery; D007557:Israel / Q000453:epidemiology; D035002:Lower Extremity / Q000098:blood supply / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009026:Mortality; D017063:Outcome Assessment, Health Care; D011183:Postoperative Complications / Q000145:classification / Q000453:epidemiology / Q000601:surgery; D012086:Reoperation / Q000706:statistics & numerical data; D012307:Risk Factors; D016896:Treatment Outcome; D014945:Wound Healing