Duration of leg pain as a predictor of outcome after surgery for lumbar disc herniation: a prospective cohort study with 1-year follow up

Object. The aim of this study was to investigate different variables in the duration of symptoms chat can be used to predict outcome after lumbar micr odiscectomy. Methods. In a prospective study of 132 consecutive patients who underwent s urgery for lumbar disc herniation, the authors evaluated the prognostic val ue of different variables in the duration of symptoms for the 1-year period after surgery. The 1-year follow-up investigation was conducted by an inde pendent observer. Assessment of outcome was performed using a clinical over all score (COS), which was recently assessed for its reliability and validi ty. As for factors predictive of outcome, only duration of leg pain and sic k leave reached statistical significance in the multivariate analysis. Resu lts of the univariate analysis demonstrated that in patients experiencing p reoperative leg pain fewer than 4 months and between 4 and 8 months, a sign ificantly lower COS at the I year follow up was demonstrated compared with those in whom the duration of leg pain was longer (> 8 months). One hundred eight patients returned to work within the Ist year after surgery. Patient s who took a sick leave of more than 28 weeks before the operation were at higher risk of not returning to work. Conclusions. Analysis of these results indicates that leg pain lasting more than 8 months correlates with an unfavorable postoperative outcome in pati ents with lumbar disc herniation, as well as a hi,oh risk of not returning to work.