title: Failure of percutaneous remodeling of the ligamentum flavum and lamina for neurogenic claudication.
abstract: BACKGROUND
  Percutaneous remodeling of the ligamentum flavum and lamina (PRLL), commercially known as minimally invasive lumbar decompression (mild technique), relies on fluoroscopy and epidural contrast to direct surgical instruments via a 6-mm cannula.
  
  
  OBJECTIVE
  To evaluate the safety and efficacy of PRLL and present, to our knowledge, the first reported imaging findings after PRLL.
  
  
  METHODS
  We performed a prospective study of PRLL for neurogenic claudication. Primary outcomes were Oswestry Disability Index, Short-Form 12 version 2.0 health survey, and visual analog scale for pain at 26 weeks. Analgesic use was also assessed. Postoperative magnetic resonance imaging was performed at 12 weeks. Long-term failure, defined as the poststudy need for secondary surgery, was assessed up to 18 months.
  
  
  RESULTS
  Ten subjects with an average age of 64 years (range, 41-81 years) were treated between September 2008 and January 2009. There were no major adverse events. Mean postoperative visual analog scale score remained significantly reduced throughout 26 weeks (P =.015, analysis of variance). Mean postoperative Oswestry Disability Index was also improved by 1 week and remained significant throughout 26 weeks (P = .024; analysis of variance). However, there was a trend toward increased reliance on narcotic type medications postoperatively. Imaging studies did not show significant decompression of the spinal canal in any patient. In the poststudy period, recurrent claudication requiring laminectomy developed in 6 patients (60%).
  
  
  CONCLUSIONS
  Throughout 26 weeks, pain and disability scores were decreased; however, PRLL did not improve the degree of stenosis on imaging studies. Although PRLL appears to be safe in this small cohort of patients, poststudy outcomes indicate that the failure rate is unacceptably high.
authors.affiliation: Division of Neurosurgery, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Wilkinson
authors.forename: Daryl R
authors.initials: DR
authors.lastname: Fourney
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019299:Decompression, Surgical / Q000379:methods*; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007383:Intermittent Claudication / Q000473:pathology / Q000601:surgery*; D007796:Laminectomy / Q000009:adverse effects*; D017843:Ligamentum Flavum / Q000601:surgery*; D017846:Longitudinal Ligaments / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011446:Prospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome