title: A multicenter, prospective, randomized trial evaluating the X STOP interspinous process decompression system for the treatment of neurogenic intermittent claudication: two-year follow-up results.
abstract: METHODS
  A randomized, controlled, prospective multicenter trial comparing the outcomes of neurogenic intermittent claudication (NIC) patients treated with the interspinous process decompression system (X STOP) with patients treated nonoperatively.
  
  
  OBJECTIVE
  To determine the safety and efficacy of the X STOP interspinous implant.
  
  
  BACKGROUND
  Patients suffering from NIC secondary to lumbar spinal stenosis have been limited to a choice between nonoperative therapies and decompressive surgical procedures, with or without fusion. The X STOP was developed to provide an alternative therapeutic treatment. METHODS.: 191 patients were treated, 100 in the X STOP group and 91 in the control group. The primary outcomes measure was the Zurich Claudication Questionnaire, a patient-completed, validated instrument for NIC.
  
  
  RESULTS
  At every follow-up visit, X STOP patients had significantly better outcomes in each domain of the Zurich Claudication Questionnaire. At 2 years, the X STOP patients improved by 45.4% over the mean baseline Symptom Severity score compared with 7.4% in the control group; the mean improvement in the Physical Function domain was 44.3% in the X STOP group and -0.4% in the control group. In the X STOP group, 73.1% patients were satisfied with their treatment compared with 35.9% of control patients.
  
  
  CONCLUSIONS
  The X STOP provides a conservative yet effective treatment for patients suffering from lumbar spinal stenosis. In the continuum of treatment options, the X STOP offers an attractive alternative to both conservative care and decompressive surgery.
authors.affiliation: St Mary's Hospital, San Francisco, California, USA. yaquai@aol.com
authors.forename: James F
authors.initials: JF
authors.lastname: Zucherman
authors.forename: Ken Y
authors.initials: KY
authors.lastname: Hsu
authors.forename: Charles A
authors.initials: CA
authors.lastname: Hartjen
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Mehalic
authors.forename: Dante A
authors.initials: DA
authors.lastname: Implicito
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Martin
authors.forename: Donald R
authors.initials: DR
authors.lastname: Johnson
authors.forename: Grant A
authors.initials: GA
authors.lastname: Skidmore
authors.forename: Paul P
authors.initials: PP
authors.lastname: Vessa
authors.forename: James W
authors.initials: JW
authors.lastname: Dwyer
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Puccio
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Cauthen
authors.forename: Richard M
authors.initials: RM
authors.lastname: Ozuna
mesh_terms: D000368:Aged; D019299:Decompression, Surgical / Q000009:adverse effects; D006801:Humans; D007383:Intermittent Claudication / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications; D019736:Prostheses and Implants; D016353:Self-Examination; D013130:Spinal Stenosis / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome