title: The positive effect of posterolateral lumbar spinal fusion is preserved at long-term follow-up: a RCT with 11-13 year follow-up.
abstract: BACKGROUND
  Few studies have investigated the long-term effect of posterolateral lumbar spinal fusion on functional outcome.
  
  
  OBJECTIVE
  To investigate the long-term result after posterolateral lumbar spinal fusion with and without pedicle screw instrumentation.
  
  
  METHODS
  Questionnaire survey of 129 patients originally randomised to posterolateral lumbar spinal fusion with or without pedicle screw instrumentation. Follow-up included Dallas Pain Questionnaire (DPQ), Oswestry Disability Index (ODI), SF-36 and a question regarding willingness to undergo the procedure again knowing the result as global outcome parameter.
  
  
  RESULTS
  Follow-up was 83% of the original study population (107 patients). Average follow-up time was 12 years (range 11-13 years). DPQ-scores were significantly lower than preoperatively in both groups (P < 0.005) and no drift towards the preoperative level was seen. No difference between the two groups were observed (instrumented vs. non-instrumented): DPQ Daily Activity mean 37.0 versus 32.0, ODI mean 33.4 versus 30.6, SF-36 PCS mean 38.8 versus 39.8, SF-36 MCS mean 49.0 versus 53.3. About 71% in both groups were answered positively to the global outcome question. Patients who had retired due to low back pain had poorer outcome than patients retired for other reasons, best outcome was seen in patients still at work (P = 0.01 or less in all questionnaires, except SF-36 MCS P = 0.08).
  
  
  CONCLUSIONS
  Improvement in functional outcome is preserved for 10 or more years after posterolateral lumbar spinal fusion. No difference between instrumented fusion and non-instrumented fusion was observed. Patients who have to retired due to low back pain have the smallest improvement.
authors.affiliation: Orthopaedic Research Laboratory, Department of Orthopaedics E, Aarhus University Hospital, Building 1A, Nørrebrogade 44, 8000, Aarhus C, Denmark. tba@dadlnet.dk
authors.forename: Thomas
authors.initials: T
authors.lastname: Andersen
authors.forename: Tina S
authors.initials: TS
authors.lastname: Videbaek
authors.forename: Ebbe S
authors.initials: ES
authors.lastname: Hansen
authors.forename: Cody
authors.initials: C
authors.lastname: Bünger
authors.forename: Finn B
authors.initials: FB
authors.lastname: Christensen
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D013122:Spinal Diseases / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D013168:Spondylolisthesis / Q000601:surgery*; D016896:Treatment Outcome; D014938:Work Capacity Evaluation