Poorer surgical outcomes at 2 years postoperatively in patients with lumbar spinal stenosis with long-term preoperative leg numbness: a single-center retrospective study

BACKGROUND: The purpose of this study was to assess whether differences in duration of preoperative leg numbness lead to different surgical outcomes. METHODS: This study included patients with lumbar spinal stenosis (LSS) who underwent lumbar fusion surgery in our hospital from January 2018 to September 2020. Patients were divided into three groups based on duration of preoperative leg numbness: no numbness (NN) group, short-term numbness (STN) group (leg numbness ≤ 3 months) and long-term numbness (LTN) group (leg numbness > 3 months). The Numerical Rating Scale of leg pain (NRS-LP) and leg numbness (NRS-LN), Oswestry Disability Index (ODI) and Short-Form Health Survey (SF-36) were collected before surgery and at 3, 6, 12 and 24 months postoperatively. RESULTS: 178 patients were included in this study. At 24 months postoperatively, NRS-LP was significantly higher in LTN than in NN [NN vs. STN vs. LTN: 0 (0,1) vs. 0 (0,1) vs. 1 (0,1)] (p = 0.033). NRS-LN in STN [2 (1,3)] was significantly lower than in LTN [3 (2,3)] (p < 0.001). SF-36 was significantly lower in LTN than in other two groups (NN vs. STN vs. LTN: 86.10 ± 6.02 vs. 84.09 ± 5.59 vs. 78.93 ± 6.57) (p < 0.001). ODI was significantly higher in LTN than in other two groups [NN vs. STN vs. LTN: 18 (15,22) vs. 18 (16,20) vs. 21 (19,24)] (p = 0.001). CONCLUSIONS: Patients with LSS with long-term preoperative leg numbness have poorer outcomes at 2 years postoperatively. Surgical intervention should be performed before persistent leg numbness for more than 3 months to obtain a better prognosis.