STUDY DESIGN: Longitudinal cohort study.
OBJECTIVES: To investigate whether a cutoff point in leg pain intensity measured preoperatively or at early follow-up could identify patients at risk of poor outcomes in terms of disability at 1-year and 2-year follow-up after first-time lumbar discectomy, and to identify the characteristics associated with early postoperative leg pain intensity.
METHODS: From 2010 to 2013, 556 patients underwent lumbar discectomy. Leg pain intensity was measured preoperatively and at early postoperative follow-up and dichotomized according to an established cutoff point on a 0 to 100 visual analogue scale (mild <30, moderate/severe ≥30). The outcome measurement was Oswestry Disability Index (ODI). Generalized estimating equations modelling established the association between leg pain intensity and ODI. Characteristics associated with early postoperative leg pain intensity were identified using common hypothesis tests.
RESULTS: Moderate/severe leg pain intensity at early follow-up showed a statistically significant association with higher ODI at 1-year and 2-year follow-up compared to mild leg pain intensity (median [interquartile range]: 24  and 26  versus 12  and 10 , respectively). Patients reporting moderate/severe leg pain intensity were more often smokers, were more prone to receive social benefits, and were more prone to have chronic back pain. The preoperative measurement of leg pain intensity showed inferior associations.
CONCLUSION: The proposed cutoff point in leg pain intensity at early follow-up can identify patients at risk of disability at both 1-year and 2-year follow-up after first-time discectomy. Future research should be undertaken to investigate whether patients with moderate/severe leg pain intensity at early postoperative follow-up could benefit from additional or more intensive postoperative interventions.