title: [Failed back surgery syndrome].
abstract: BACKGROUND
  Failed back surgery syndrome (FBSS) is well known and physicians often fear this outcome. Its definition is difficult to understand because it is multifactorial. However, we analyze its etiology in order to determine if it is from iatrogenic causes. This syndrome can be categorized as follows: mistaken diagnoses, transoperative error, technique error, poor application, poor indication.
  
  
  METHODS
  We undertook a prospective, observational and lineal study in 20 patients, 313 surgeries and 4,500 consultations. Age and gender variables were analyzed, number of prior surgeries, and diagnosis prior to first surgery, as well as predominant symptoms for the last surgery, surgical time, and involved segment. Patients were evaluated with Oswestry preoperative scale and followed up for 2 years.
  
  
  RESULTS
  There were 16 females and 4 males with an average age of 53.2 years. Eight patients had 1 prior surgery, 8 patients had 2 prior surgeries, 3 patients had 3 prior surgeries, and 1 patient had 4 prior surgeries. According to the Oswestry preoperative scale, 12 patients had scores higher than 60% and at 2-year follow-up, 11 patients had scores lower than 20%. Despite the persistent symptomatology and complications, in almost all patients the satisfaction index was 100%. According to the evaluation, the main cause was poor indication in three patients, poor indication + technique error in 10, and technique error in 7 patients.
  
  
  CONCLUSIONS
  The most reported initial etiology was lumbar disc hernia with minimally invasive treatment with questionable surgical indication.
authors.affiliation: Servicio de Cirugía de Columna Vertebral, Instituto Nacional de Rehabilitación/Ortopedia, México, D.F., Mexico.
authors.forename: Luis Miguel
authors.initials: LM
authors.lastname: Rosales-Olivares
authors.forename: Víctor
authors.initials: V
authors.lastname: Miramontes-Martínez
authors.forename: Armando
authors.initials: A
authors.lastname: Alpízar-Aguirre
authors.forename: Alejandro
authors.initials: A
authors.lastname: Reyes-Sánchez
mesh_terms: D000328:Adult; D000368:Aged; D001416:Back Pain / Q000601:surgery*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017211:Treatment Failure