title: Neuropathic complications after 157 procedures of continuous popliteal nerve block for hallux valgus surgery. A retrospective study.
abstract: BACKGROUND
  Continuous peripheral nerve block (CPNB), in particular at the popliteal fossa, is widely used in orthopedic surgery, allowing good postoperative analgesia. Possible neuropathic complications, however, remain poorly known.
  
  
  OBJECTIVE
  To review the characteristics of peripheral neuropathy (PN) after sciatic CPNB at the popliteal fossa, estimating prevalence, severity, evolution and possible risk factors, especially those relating to the procedure.
  
  
  METHODS
  Retrospective study of PN associated with popliteal fossa CPNB for hallux valgus surgery, between November 1st, 2005 and November 1st, 2009. All procedures were analyzed (type of anesthesia, approach, nerve location technique, number of procedures by operator) with, for each case of PN, analysis of clinical and electromyographic data.
  
  
  RESULTS
  One hundred and fifty seven sciatic CPNBs were performed (92% women; mean age, 55 years). The approach was lateral (n=62), posterior (n=74) or unknown (n=21). Ultrasound guidance was combined to neurostimulation for 69 patients (44%). Three women (prevalence=1.91%), aged 19, 24 and 65 years respectively, developed associated common superficial peroneal and sural nerve injury (2), axonal on electromyography, with motor (n=1) and/or sensory (n=3) residual dysfunction.
  
  
  CONCLUSIONS
  The higher prevalence found in the present study than in the literature (0 to 0.5%) raises questions of methodological bias or technical problems. The common peroneal and sural nerves seem to be exposed, unlike the tibial. Several mechanisms can be suggested: anesthetic neurotoxicity, direct mechanical lesion, or tourniquet-related ischemia and conduction block. Further studies are necessary to determine the ideal anesthetic procedure.
  
  
  CONCLUSIONS
  Patients should be informed of the potential risk, however rare, even during mild surgery. The best possible technique should be implemented, with reinforced surveillance.
authors.affiliation: Neurology department, Desgenettes military teaching hospital, 69275 Lyon, France. Valentin.hajek@gmail.com
authors.forename: V
authors.initials: V
authors.lastname: Hajek
authors.forename: C
authors.initials: C
authors.lastname: Dussart
authors.forename: F
authors.initials: F
authors.lastname: Klack
authors.forename: A
authors.initials: A
authors.lastname: Lamy
authors.forename: J-Y
authors.initials: JY
authors.lastname: Martinez
authors.forename: P
authors.initials: P
authors.lastname: Lainé
authors.forename: L
authors.initials: L
authors.lastname: Mazurier
authors.forename: L
authors.initials: L
authors.lastname: Guilloton
authors.forename: A
authors.initials: A
authors.lastname: Drouet
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006215:Hallux Valgus / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects* / Q000379:methods; D010543:Peroneal Nerve / Q000293:injuries* / Q000503:physiopathology; D020427:Peroneal Neuropathies / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D011183:Postoperative Complications; D015995:Prevalence; D012189:Retrospective Studies; D012720:Severity of Illness Index; D055815:Young Adult