Varied Low Back Pain Induced by Different Spinal Tissues in Percutaneous Endoscopic Lumbar Discectomy: A Retrospective Study

Background: Percutaneous endoscopic lumbar discectomy (PELD) has become a mature and mainstream minimally invasive surgical technique for treating lumbar disc herniation (LDH). During PELD, various spinal structures, such as ligamentum flavum, dural sac, nerve root, posterior longitudinal ligament, annulus fibrosus, and endplate, were exposed, removed, and decompressed. When we used different endoscopic instruments to touch, remove, and excise different spinal structures, the patient will experience varying degrees of low back pain (LBP). To the best of our knowledge, the differences of the LBP have not been investigated in detail. Objectives: To evaluate the spinal structures pain variability during PELD. Study Design: A retrospective study. Setting: All data were collected from Shandong Provincial Hospital Affiliated to Shandong First Medical University. Methods: From February 2017 to May 2021, 1,100 patients with LDH underwent PELD surgery. During the operation, the Visual Analog Scale (VAS) was used to assess the pain intensity of each patient, generated by physical stimuli of different endoscopic instruments (i.e., nucleus pulposus forceps, punch forceps, and radiofrequency bipolar coagulator) in different tissue (i.e., posterior longitudinal ligament, nerve root /dural sac, endplate, and ligamentum flavum). Data were analyzed by analysis of variance with Bonferroni post hoc tests. Results: As for the VAS for LBP among different spinal tissues, the degree of LBP was reduced in each group in the following order (decreasing from most severe to mildest): posterior longitudinal ligament, nerve root/dural sac, endplate, ligamentum flavum, annulus fibrosus (P < 0.01). As for the VAS for LBP caused by different endoscopic instruments, we found the most intense LBP always caused by nucleus pulposus forceps, next by punch forceps, then by radiofrequency bipolar coagulator (P < 0.01). Limitations: The retrospective nature of data collection and the educational discrepancies among the trial population may affect data collection to some extent. Conclusions: During PELD, varied LBP will generate when different spinal tissues are manipulated by different endoscopic instruments, the most severe LBP always came from the posterior longitudinal ligament and nerve root /dural sac. Moreover, compared to incision and thermal stimulus, traction could provoke more severe LBP.