OBJECTIVE Decompression surgery is a mainstay of surgical treatment for lumbar spinal stenosis (LSS). However, up to 30% of patients have low satisfaction due to residual symptoms. In the clinical setting, improvements in leg pain are more significant than those in leg numbness. Residual numbness could be related to the relatively low satisfaction rate. However, few studies have focused on numbness; thus, elucidating the risk factors and rate of residual numbness would benefit surgeons and patients. This study aimed to clarify the risk factors for and rate of residual numbness after decompression surgery. PATIENTS AND METHODS We retrospectively reviewed prospectively collected data from consecutive patients who underwent lumbar decompression without fusion for LSS at a single institution between January 2014 and March 2016. Patients were included if preoperative and final follow-up questionnaires and radiographs were available. A minimum one-year follow-up was required. We evaluated the Numeric Rating Scale (NRS) scores of low back pain, leg pain, and leg numbness preoperatively and at the final follow-up visit. Residual numbness was defined as a postoperative NRS ≥ 1, whereas persistent numbness was defined as a postoperative NRS ≥ 5. We compared the clinical data of patients with or without residual numbness to those of patients with or without persistent numbness. Multivariate logistic regression analysis was performed to identify risk factors for residual and persistent numbness. RESULTS A total of 116 patients (73 men, 43 women) were included. Of them, 60% had residual numbness with a mean follow-up period of 25 months. Only durotomy differed significantly between patients with and those without residual numbness. However, the significance did not persist after logistic regression analysis. A total of 16% had persistent numbness. Diabetes mellitus, intraoperative durotomy, and preoperative NRS of numbness were identified as risk factors. There were no differences in smoking status, presence of spondylolisthesis or scoliosis, or severity of stenosis. CONCLUSIONS We found three risk factors for persistent numbness following decompression surgery for LSS; diabetes mellitus and durotomy were modifiable, whereas preoperative numbness was not. Our findings would help surgeons minimize the incidence of persistent numbness by adequately controlling diabetes and avoiding durotomy during surgery. Providing information about the potential for residual numbness during the informed consent process is important to ensuring realistic patient expectations.

中文翻译：

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腰椎管狭窄症减压术后持续性麻木的危险因素

目的 减压手术是腰椎管狭窄症 (LSS) 的主要手术治疗方法。然而，高达 30% 的患者由于残留症状而满意度较低。在临床环境中，腿部疼痛的改善比腿部麻木的改善更显着。残留的麻木感可能与相对较低的满意度有关。然而，很少有研究关注麻木。因此，阐明残留麻木的风险因素和发生率将使外科医生和患者受益。本研究旨在阐明减压手术后残留麻木的危险因素和发生率。患者和方法 我们回顾性地回顾了 2014 年 1 月至 2016 年 3 月期间在单一机构接受腰椎减压但未融合 LSS 的连续患者的前瞻性收集数据。如果术前和最终随访问卷和 X 光片可用，则患者被包括在内。需要至少一年的随访。我们在术前和最后一次随访时评估了腰痛、腿部疼痛和腿部麻木的数字评定量表 (NRS) 评分。残余麻木定义为术后 NRS ≥ 1，而持续麻木定义为术后 NRS ≥ 5。我们比较了有或没有残余麻木的患者与有或没有持续麻木的患者的临床数据。进行多变量逻辑回归分析以确定残留和持续麻木的危险因素。结果 共纳入 116 名患者（73 名男性，43 名女性）。其中，60% 有残留麻木，平均随访时间为 25 个月。只有硬膜切开术在有和没有残留麻木的患者之间有显着差异。然而，在逻辑回归分析后，显着性并不持续。共有 16% 的人有持续性麻木。糖尿病、术中硬膜切开术和术前麻木 NRS 被确定为危险因素。吸烟状况、脊椎滑脱或脊柱侧弯的存在或狭窄的严重程度没有差异。结论 我们发现 LSS 减压手术后持续麻木的三个危险因素；糖尿病和硬膜切开术是可以改变的，而术前麻木则不是。我们的研究结果将帮助外科医生通过充分控制糖尿病和避免在手术过程中进行硬膜切开来最大限度地减少持续麻木的发生率。