Risk Factors in the Prediction of Leg Numbness after Spinal Endoscopic Surgery: Evaluation and Development of a Nomogram

Abstract

Purpose. This study aims at constructing a clinical predictive model that predicted the risk factors for leg numbness after spinal endoscopic surgery. Methods. We collected the clinical data of patients, including general information, imaging parameters, and clinical score, from our hospital’s electronic database. Based on the postoperative leg numbness visual analog scale (LN-VAS), the clinical data were divided into the leg numbness group (≥25) and the improvement group (<25). All parameters were included in the least absolute shrinkage and selection operator (LASSO) regression analysis, while the parameters with the area under the curve (AUC) greater than 0.7 were selected to construct nomograms. Furthermore, the accuracy and validity of the model were evaluated using the C-index, decision curve analysis (DCA), calibration curve, and receiver operating characteristic curve (ROC). Results. A total of 73 patients’ clinical data were included in the training set, where 51 patients were assigned to the improvement group and 22 to the leg numbness group. The nomogram was constructed using four selected parameters, including symptom duration, lumbar spinal stenosis (LSS), pelvic incidence (PI), and preoperative low back pain visual analog scale (LBP-VAS). The nomogram predictions were found to range between 0.01 and 0.99. The values of the C-index, AUC, and internally validated C-index were 0.96, 0.96, and 0.94, respectively. Our result showed that the clinical net benefit of the nomogram ranged between 0.01 and 0.99. Conclusion. Our clinical prediction model demonstrated high predictive ability and clinical validity. Moreover, we found that symptom duration, LSS, PI, and preoperative LBP-VAS were the predictive risk factors for leg numbness after spinal endoscopic surgery.

Risk factor of residual leg numbness after lumbar microdiscectomy for lumbar disc herniation

“…[ 7 ] A retrospective study of 73 patients with LDH by Yi et al (2022) found that LN after spinal endoscopic surgery was associated with longer symptom duration, pelvic incidence, preoperative LBP VAS score, and LDH combined with LSS. [ 11 ] Additionally, a study by Tsujimoto et al (2023) on symptomatic postoperative lumbar epidural hematoma also found that compared to early removal of hematoma, delayed removal of hematoma can also improve LBP and LP but not LN. [ 18 ] Therefore, patients in the RLN group had a longer preoperative LN duration in the present study.…”

“…[6][7][8][9] However, only a few studies have specifically investigated the potential risk factors of RLN after microdiscectomy in patients with LDH. [10,11] The association of clinical and radiological factors, such as sex, age, body mass index (BMI), current smoking, diabetes mellitus, duration of preoperative LN, preoperative LN NRS score, RLN at discharge, revision surgery, sagittal range of motion (SROM), intervertebral Modic change, disc Pfirrmann grade with RLN remains unclear.…”