Background Percutaneous endoscopic lumbar discectomy (PELD) is an increasingly applied minimally invasive procedure that has several advantages in the treatment of lumbar disc herniation (LDH). However, recurrent LDH (rLDH) has become a concerning postoperative complication. It remains difficult to establish a consensus and draw reliable conclusions regarding the risk factors for rLDH. Purpose This retrospective study aimed to investigate the risk factors associated with rLDH at the L4-5 level after percutaneous endoscopic transforaminal discectomy (PETD). Methods A total of 654 patients who underwent the PETD procedure at the L4-5 level from October 2013 to January 2020 were divided into a recurrence (R) group (n=46) and a nonrecurrence (N) group (n=608). Demographic and clinical data and imaging parameters were collected and analyzed using univariate and multiple regression analyses. Results The current study found a 7% rate of rLDH at the L4/5 level after successful PETD. Univariate analysis showed that older age, high BMI, diabetes mellitus history, smoking, large physical load intensity, moderate disc degeneration, small muscle–disc ratio (M/D), more fat infiltration, large sagittal range of motion (sROM), scoliosis, small disc height index (DHI), small intervertebral space angle (ISA), and small lumbar lordosis (LL) were potential risk factors (P < 0.10) for LDH recurrence after PETD at the L4-5 level. Multivariate analysis suggested that high BMI, large physical load intensity, moderate disc degeneration, small M/D, more fat infiltration, large sROM, small ISA, and small LL were independent significant risk factors for recurrence of LDH after PETD. Conclusion Consideration of disc degeneration, M/D, fat infiltration of the paravertebral muscles, sROM, ISA, LL, BMI, and physical load intensity prior to surgical intervention may contribute to the prevention of rLDH following PETD and lead to a more satisfactory operative outcome and the development of a reasonable rehabilitation program after discharge.

Purpose: To compare the clinical effects of local anesthesia (LA), general anesthesia (GA) and modified sensation-motion separation anesthesia (MA) in percutaneous endoscopic interlaminar discectomy (PEID) in the treatment of L5/S1 lumbar disc herniation (LDH) for the purpose of guiding junior surgeons. Methods: Eighty-four patients with L5/S1 LDH underwent PEID using three anesthesia methods. Patients in the LA (26), GA (29) and MA (29) groups received a follow-up examination retrospectively. The general parameters, preparation and anesthesia duration, operative duration, recovery time, incidence of complications, ambulation time, length of hospital stay, incidence of severe complications, and reoperation rate were compared, and clinical outcomes were analyzed using a visual analog scale (VAS), the Oswestry Disability Index (ODI), and the Short-Form Health Survey 36 (SF-36). Results: MA demonstrated obvious advantages over the other two methods with respect to operative duration and resulted in a better intraoperative experience than LA. The patients in the MA group required less time in bed postoperatively and shorter hospital stays than those in the GA group. The mean postoperative VAS, ODI and SF-36 scores were significantly better than the preoperative scores in all groups (P<0.05), but no significant differences in these scores were found among the three groups (P>0.05). Three cases (3/29) of nervous disorder occurred in the GA group. Two patients (one in the GA group (1/29) and one in the LA (1/26) group) underwent revision surgery, with a total recurrence rate of 2.4% (2/84). Conclusion: Due to its high safety and good tolerance by patients, MA is a suitable method for spinal surgeons who are inexperienced with PEID in the treatment of L5/S1 disc herniation.

Previous studies have reported that the Ras homolog family member A (RhoA)/myocardin-related transcription factor A (MRTF-A) nuclear translocation axis positively regulates fibrogenesis induced by mechanical forces in various organ systems. The aim of the present study was to determine whether this signaling pathway was involved in the pathogenesis of nucleus pulposus (NP) fibrosis induced by mechanical overload during the progression of intervertebral disc degeneration (IVDD) and to confirm the alleviating effect of an MRTF-A inhibitor in the treatment of IVdd. NP cells (NPcs) were cultured on substrates of different stiffness (2.9 and 41.7 KPa), which mimicked normal and overloaded microenvironments, and were treated with an inhibitor of MRTF-A nuclear import, ccG-1423. In addition, bipedal rats were established by clipping the forelimbs of rats at 1 month and gradually elevating the feeding trough, and in order to establish a long-term overload-induced model of IVdd, and their intervertebral discs were injected with ccG-1423 in situ. cell viability was determined by cell counting Kit-8 assay, and protein expression was determined by western blotting, immunofluorescence and immunohistochemical staining. The results demonstrated that the viability of NPcs was not affected by the application of force or the inhibitor. In NPcs cultured on stiff matrices, MRTF-A was mostly localized in the nucleus, and the expression levels of fibrotic proteins, including type I collagen, connective tissue growth factor and α-smooth muscle cell actin, were upregulated compared with those in NPcs cultured on soft matrices. The levels of these proteins were reduced by ccG-1423 treatment. In rats, 6 months of upright posture activated MRTF-A nuclear-cytoplasmic trafficking and fibrogenesis in the NP and induced IVdd; these effects were alleviated by ccG-1423 treatment. In conclusion, the results of the present study demonstrated that the RhoA/MRTF-A translocation pathway may promote mechanical overload-induced fibrogenic activity in NP tissue and partially elucidated the molecular mechanisms underlying the occurrence of IVdd.

Study Design: A retrospective cohort study.Purpose: To compare the clinical effects of local anesthesia (LA), general anesthesia (GA) and modified sensation-motion separation anesthesia (MA) in percutaneous endoscopic interlaminar discectomy (PEID) for treating L5/S1 lumbar disc herniation (LDH) and guide the junior surgeons.Patients and methods: Eighty-four patients with L5/S1 LDH underwent PEID using three anesthesia methods. Patients in groups LA (26), GA (29) and MA (29) were given a follow-up examination retrospectively. General parameters, preparation and anesthesia time, operation time, recovery time, incidence rate of complications, ambulation time, length of hospital stay, severe complications, and reoperation rate were compared, and clinical outcomes were analyzed using a visual analog scale (VAS), the Oswestry Disability Index (ODI), and the Short-Form Health Survey 36 (SF-36).Results: MA demonstrated obvious advantages over the other two methods in operation time and led a better intraoperative experience than LA. Group MA and LA required less time in bed postoperatively and shorter hospital stays than group GA. The mean postoperative VAS score, ODI score and SF-36 score were significantly better than the preoperative values in all groups (P<0.05), but no significant differences were found among the three groups (P>0.05). Three cases (3/29) of nervous disorder occurred in the GA group. Two cases in the GA (1/29) and LA (1/26) groups were revised among all three groups, with a total recurrence rate of 2.4% (2/84). Conclusions: Modified anesthesia with sensation-motion separation was a suitable method for spinal surgeons who were inexperienced with PEID in the treatment of L5/S1 disc herniation due to its high safety and good patient tolerance.