Abstract: Objective To investigate the effect and follow-up results of percutaneous foraminal endoscopic discectomy (PTED) assisted by a novel three-axis adjustable positioner in the treatment of multi-segment lumbar disc herniation (LDH). 
Methods A total of 100 patients with multi-segment LDH in our hospital were selected and divided into two groups by simple randomization method, with 50 patients in each group. The control group received traditional PTED, and the observation group received PTED assisted by a novel three-axis adjustable positioner. Perioperative indexes, complications, excellent and good rate of surgery, inflammatory stress indexes ［interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-17 (IL-17)］, surface electromyography ［root mean square (RMS) value, median frequency (MF)value, integrated electromyography (IEMG) of multifidus muscle on the affected side］,Oswestry Disability Index (ODI) score, visual analog scale (VAS) score, and excellence and good rate of surgery of the two groups before and after surgery were observed and compared. 
Results The number of fluoroscopy, puncture times and intraoperative blood loss in the observation group were less than those in the control group, the puncture time and duration of operation were shorter than those in the control group, and the success rate of one-time puncture was higher than that in the control group (P＜0.05). There was no significant difference in the incidence of complications between the two groups (P＞0.05). The serum levels of IL-17, IL-6 and IL-2 in the observation group were lower than those in the control group at 1 d after surgery (P＜0.05). RMS, MF and IEMG of multifidus muscle on the affected side were higher than those before surgery, and at 1 month, 3 months, 6 months and 12 months after surgery, while ODI scores were lower than those before surgery (P＜0.05). The VAS scores of the lower back and lower limbs in the observation group were lower than those in the control group at 1 and 5 d after surgery (P＜0.05). At 12 months after surgery, there was no significant difference in excellent and good rate of surgery between the two groups (P＞0.05). 
Conclusion The novel three-axis adjustable positioner assisted PTED and traditional PTED can achieve satisfactory results in the treatment of multi-segment LDH, which can improve the surface electromyography of the multifidus muscle on the affected side, restore the function of the lumbar spine, relieve the pain of patients, and has good safety. However, the former can optimize the operation, shorten the duration of operation, reduce postoperative inflammation, and contribute to early pain relief. 

Key words: intervertebral disc displacement, foraminal endoscopic surgery, new three-axis adjustable positioner