The evaluation of the surgical management of nerve root compression in patients with low back pain - Part 1: The assessment of outcome

Study Design. This was a prospective study investigating the outcome of decompression surgery using validated measures of outcome. Objectives. To investigate the outcome of lumbar decompressive surgery in the initial postoperative year period in terms of function, disability, general health, and psychological well-being. Summary of Background Data. The majority of studies investigating the outcome of lumbar decompression surgery have been retrospective and have not used validated measures of outcome. This limits their interpretation and usefulness. Methods. Eighty-four patients undergoing lumbar spinal stenosis surgery were recruited into this study. Patients were assessed by use of validated measures of outcome including the Oswestry Disability Index and the Short Form SF-36 General Health Questionnaire before surgery and 6 weeks, 6 months, and 1 year after surgery. Results. A significant reduction in pain (P < 0.001) was observed at the 6-week postoperative stage; this did not change at the subsequent assessment stages. Only some of the SF-36 categories were sensitive to change, The subcategories that were sensitive to change were physical function (P < 0.05), bodily pain (P < 0.001), and social function (P < 0.05). Improvements were observed in these categories at the 6-week and 6-month reviews. A gradual reduction in the Oswestry Disability Index was observed with time, with changes principally being observed between the 6-week and 6-month review and the 6-week and 1-year review stages (P < 0.05). Minimal changes were observed in the psychological assessments with time. The outcome of surgery could not be predicted reliably from psychological, functional, or pain measures. Conclusions. The visual analogue pain scales, the Oswestry Disability Index, and certain categories of the SF-36 Questionnaire, namely bodily pain and physical and social function, appeared to be the most sensitive outcome measures, with significant improvements occurring at the 6-week and 6-month reviews.