title: The degree of decompressive relief and its relation to clinical outcome in patients undergoing surgery for lumbar spinal stenosis.
abstract: METHODS
  A cross-sectional, clinical study to evaluate surgical decompression of the stenotic area monitored by computed tomographic scan and its relation to clinical variables in patients operated on for lumbar spinal stenosis.
  
  
  OBJECTIVE
  To study in patients with lumbar spinal stenosis the influence of the degree of compressive relief on the patients' clinical outcome.
  
  
  BACKGROUND
  The goal of surgical treatment in lumbar spinal stenosis is to decompress the stenotic area. Although the decompression should be adequate, there are no clear guidelines to determine the extent of necessary decompression. In fact, there is clinical evidence that there is a discrepancy between the surgical outcome in the patient with lumbar spinal stenosis and postoperative radiologic findings.
  
  
  METHODS
  In 92 patients with lumbar spinal stenosis who had had no prior back surgery, preoperative and postoperative computed tomographic scans were obtained to determine the degree of decompression. The postoperative scan findings were classified according to the degree of decompression into a no-stenosis group (n = 35), an adjacent-stenosis group (n = 27), and a residual-stenosis group (n = 30). The postoperative instability of the lumbar spine was investigated by functional radiography. The subjective disability of the patients was assessed using the Oswestry score and the severity of pain using the visual analog scale. Walking capacity was evaluated by a treadmill test. The patients' estimations of the results of surgery were classified into groups of satisfied patients and dissatisfied patients.
  
  
  RESULTS
  The mean Oswestry score in all 92 patients was 27.1, and mean walking capacity was 630 m. In the satisfied patients, the Oswestry score was 18.8 and in the dissatisfied patients, 34.9 (P < 0.0000). Walking capacity was 690 m and 594 m, respectively. There were 30 patients with postoperative spinal instability, but it had no influence on surgical outcome. There were no differences in the Oswestry score, walking capacity, and patients' satisfaction among the postoperative CT groups. In the linear regression analysis, the satisfied patient corresponded significantly with the Oswestry score.
  
  
  CONCLUSIONS
  The satisfaction of the patients with the results of surgery was more important in surgical outcome than the degree of decompression detected on computed tomographic scan.
authors.affiliation: Department of Physical and Rehabilitation Medicine, Kuopio University Hospital, Finland. arto.herno@kuh.fi
authors.forename: A
authors.initials: A
authors.lastname: Herno
authors.forename: T
authors.initials: T
authors.lastname: Saari
authors.forename: O
authors.initials: O
authors.lastname: Suomalainen
authors.forename: O
authors.initials: O
authors.lastname: Airaksinen
mesh_terms: D003430:Cross-Sectional Studies; D019299:Decompression, Surgical; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010147:Pain Measurement; D017060:Patient Satisfaction; D012044:Regression Analysis; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology