title: Dynamic interspinous stabilization in lumbar discectomy: 4-year follow-up.
abstract: BACKGROUND
  Semirigid posterior stabilization is an alternative, avoiding arthrodesis in operated segments. However, this results in the need for dynamic stabilization to allow a stable feature function.
  
  
  METHODS
  We conducted a prospective longitudinal self-reported interventional study. We included 46 patients with dynamic Dallostype interspinous stabilization between 1997 and 2004. A 4-year follow-up analysis was performed using clinical and radiographic studies, preoperatively and 4 years later evaluating lumbar disability, pain, disc height, disc angle (neutral, flexion, and extension). Descriptive statistics were used along with Wilcoxon signed range test. Statistical significance was accepted when p < 0.05.
  
  
  RESULTS
  Of 46 patients, 39 completed a 4-year follow-up. Included in the study were nine females and 30 males with an average age of 30.74 years. Affected levels were L4 and L5 (21 patients); L5/S1 (17 patients) and L3/L4 (one patient). An improvement was reported of 80.3% according to the Oswestry scale (p = 0.0001). Preoperative pain decreased 6.8 points VAS. Disc height decreased 0.1 mm on average without significance. Disc angle (neutral) increased 1.13° without statistical difference. For flexion the increase was 2.641° (p = 0.0002), and extension decreased 0.817° on average without statistical significance. Range of mobility decreased 3.416° (p = 0.004).
  
  
  CONCLUSIONS
  Interspinous ligamentoplasty improves segmental stability, allowing mobility within normal ranges and preserving disc height at 4 years of follow-up, as well as offering greater dynamic stability. Successful clinical improvement was demonstrated.
authors.affiliation: Servicio de Cirugía de Columna Vertebral, Instituto Nacional de Rehabilitación, Secretaría de Salud, México, D. F., Mexico.
authors.forename: Luis Miguel
authors.initials: LM
authors.lastname: Rosales-Olivares
authors.forename: Armando
authors.initials: A
authors.lastname: Alpízar-Aguirre
authors.forename: Víctor
authors.initials: V
authors.lastname: Miramontes-Martínez
authors.forename: Barón
authors.initials: B
authors.lastname: Zárate-Kalfópulus
authors.forename: Alejandro
authors.initials: A
authors.lastname: Reyes-Sánchez
mesh_terms: D000293:Adolescent; D000328:Adult; D017586:Diskectomy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors; D055815:Young Adult