title: Preoperative MRI findings predict two-year postoperative clinical outcome in lumbar spinal stenosis.
abstract: OBJECTIVE
  To study the predictive value of preoperative magnetic resonance imaging (MRI) findings for the two-year postoperative clinical outcome in lumbar spinal stenosis (LSS).
  
  
  METHODS
  84 patients (mean age 63±11 years, male 43%) with symptoms severe enough to indicate LSS surgery were included in this prospective observational single-center study. Preoperative MRI of the lumbar spine was performed with a 1.5-T unit. The imaging protocol conformed to the requirements of the American College of Radiology for the performance of MRI of the adult spine. Visual and quantitative assessment of MRI was performed by one experienced neuroradiologist. At the two-year postoperative follow-up, functional ability was assessed with the Oswestry Disability Index (ODI 0-100%) and treadmill test (0-1000 m), pain symptoms with the overall Visual Analogue Scale (VAS 0-100 mm), and specific low back pain (LBP) and specific leg pain (LP) separately with a numeric rating scale from 0-10 (NRS-11). Satisfaction with the surgical outcome was also assessed.
  
  
  RESULTS
  Preoperative severe central stenosis predicted postoperatively lower LP, LBP, and VAS when compared in patients with moderate central stenosis (p<0.05). Moreover, severe stenosis predicted higher postoperative satisfaction (p = 0.029). Preoperative scoliosis predicted an impaired outcome in the ODI (p = 0.031) and lowered the walking distance in the treadmill test (p = 0.001). The preoperative finding of only one stenotic level in visual assessment predicted less postoperative LBP when compared with patients having 2 or more stenotic levels (p = 0.026). No significant differences were detected between quantitative measurements and the patient outcome.
  
  
  CONCLUSIONS
  Routine preoperative lumbar spine MRI can predict the patient outcome in a two-year follow up in patients with LSS surgery. Severe central stenosis and one-level central stenosis are predictors of good outcome. Preoperative finding of scoliosis may indicate worse functional ability.
authors.affiliation: Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland and Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Kuittinen
authors.affiliation: Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland and Unit of Radiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Petri
authors.initials: P
authors.lastname: Sipola
authors.affiliation: Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland and Unit of Neurosurgery, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Ville
authors.initials: V
authors.lastname: Leinonen
authors.affiliation: Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Tapani
authors.initials: T
authors.lastname: Saari
authors.affiliation: Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland.
authors.forename: Sanna
authors.initials: S
authors.lastname: Sinikallio
authors.affiliation: Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Sakari
authors.initials: S
authors.lastname: Savolainen
authors.affiliation: Department of Orthopaedics and Traumatology, Kuopio University Hospital and Bone and Cartilage Research Unit, University of Eastern Finland, Kuopio, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Kröger
authors.affiliation: Department of Orthopaedics and Traumatology, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Veli
authors.initials: V
authors.lastname: Turunen
authors.affiliation: Department of Physical and Rehabilitation Medicine, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Olavi
authors.initials: O
authors.lastname: Airaksinen
authors.affiliation: Health Center Ikioma OY, Mikkeli, Finland.
authors.forename: Timo
authors.initials: T
authors.lastname: Aalto
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D013130:Spinal Stenosis / Q000473:pathology / Q000601:surgery*