Risk Factors for Short-Term and Long-Term Low Back Pain After Transforaminal Endoscopic Lumbar Discectomy

INTRODUCTION: Low back pain following transforaminal endoscopic lumbar discectomy (TELD) is prevalent (15–25% incidence). Modifying TELD techniques to avoid excessive disc removal has been suggested to reduce such pain. Facet injury, re-herniation, and disc space collapse might contribute. This retrospective study aimed to explore factors linked to post-TELD low back pain. METHODS: A total of 351 patients with L3/4, L4/5, and L5/S1 intervertebral lumbar disc herniations, who underwent TELD at two spine centers, were included. Patients were followed for one year. Low back and leg pain visual analogue scale (VAS) scores, Oswestry Disability Index (ODI), Pfirrmann grade, and disc height were measured at 3 months and 1 year. Correlation analyses examined links between postoperative low back pain VAS scores, age, sex, disc/vertebrae height ratio (D/V H ratio), Pfirrmann grade, cannula position grade, re-herniation grade, high-intensity zone (HIZ), disc calcification, surgical grade, and other factors. Significant variables were identified using partial least square tests, with variable importance in projection (VIP) values quantifying their impact on low back pain. RESULTS: Univariate analysis indicated that surgical grade correlated with long-term postoperative low back pain (P = 0.023), while re-herniation (P = 0.008, P = 0.000), disc height (P = 0.001, P = 0.034), and sex (P = 0.025, P = 0.003) correlated with both short- and long-term postoperative low back pain. Trephine/cannula position is correlated with short-term low back pain (P = 0.036). Worsening low back pain was associated with female sex, improper trephine/cannula position, re-herniation, and post-surgical disc space collapse. Intradiscal irrigation was linked to decreased low back pain. DISCUSSION: This study highlights factors influencing low back pain after TELD. Loss of disc height, extent of re-herniation, quality of trephine/cannula position, and sex were associated with low back pain at both 3 months and 1-year post-TELD. Proper techniques, like minimizing disc height loss and re-herniation, may help mitigate postoperative low back pain.