title: Incidence and severity of complications due to femoral nerve blocks performed for knee surgery.
abstract: BACKGROUND
  While single shot femoral nerve blocks and indwelling femoral nerve catheters provide significant peri-operative analgesia, there are small but serious risks of neurovascular complications. We aimed to determine the incidence and characterise the nature of neural complications arising from femoral nerve blocks performed for knee surgery.
  
  
  METHODS
  One thousand eight hundred and two patients receiving a femoral nerve block for knee surgery during the study period were screened. Patients with possible neurological symptoms were evaluated with a detailed physical examination and self-report questionnaires. Also measures of depression, anxiety and tension/stress were collected.
  
  
  RESULTS
  In the patients screened, an incidence of 1.94% was found. Of the 24 patients available for testing, 4 had bilateral symptoms following bilateral nerve blocks. All had sensory abnormalities in the distribution of the femoral nerve. The incidence was significantly higher in females (females=2.5%, males=0.83% p=0.01) and in patients receiving a single shot block (single shot=2.66%, femoral catheter=0.93, p=0.01).
  
  
  CONCLUSIONS
  The incidence of neurological complication after FNB was higher in this series than typically reported and the symptoms significantly influenced the quality of life in the affected cases. The decision to include a femoral nerve block in the peri-operative analgesic regimen should be made on an individual basis considering the risks and benefits.
authors.affiliation: Sydney Orthopaedic Research Institute, Chatswood, NSW, Australia.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Widmer
authors.forename: Sébastien
authors.initials: S
authors.lastname: Lustig
authors.forename: Corey J
authors.initials: CJ
authors.lastname: Scholes
authors.forename: Allen
authors.initials: A
authors.lastname: Molloy
authors.forename: Sean P M
authors.initials: SP
authors.lastname: Leo
authors.forename: Myles R J
authors.initials: MR
authors.lastname: Coolican
authors.forename: David A
authors.initials: DA
authors.lastname: Parker
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000009:adverse effects*; D001178:Arthroplasty / Q000009:adverse effects*; D001315:Australia / Q000453:epidemiology; D005260:Female; D005267:Femoral Nerve / Q000187:drug effects*; D006801:Humans; D015994:Incidence; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects*; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D011795:Surveys and Questionnaires; D055815:Young Adult