Comparison of Clinical and Radiographic Outcomes Between Transforaminal Endoscopic Lumbar Discectomy and Microdiscectomy: A Follow-up Exceeding 5 Years.

OBJECTIVE: To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD). METHODS: The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients' clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated. RESULTS: During a mean follow-up of 5.5 years (range, 5-7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio. CONCLUSION: Both TELD and MD provide generally satisfactory long-term clinical outcomes for patients with LDH. TELD can be used as a reliable alternative to MD with less surgical trauma. Modic type II changes, decreased preoperative intervertebral height, and a high body mass index are predictors of a poor prognosis.

DNA methylation mediates gonadal development via regulating the expression levels of cyp19a1a in loach Misgurnus anguillicaudatus.

DNA methylation-mediated transcriptional regulation has been considered to significantly impact some steroidogenic enzyme genes expression. To uncover the roles of DNA methylation on the regulation of aromatase gene expression during gametogenesis in Misgurnus anguillicaudatus, the expression profiles and cellular localization of cyp19a1a and cyp19a1b were analyzed, and the landscape of DNA methylation dynamics was investigated. We found that cyp19a1a was predominantly expressed in granulosa cells of oocytes, while cyp19a1b expression was enriched in radial glial cells of the forebrain. In ovary, cyp19a1a was highly expressed until the vitellogenesis stage. The average methylation levels, especially for two CpG sites within the cAMP response element, were negatively correlated with cyp19a1a expression levels, indicating that methylation could regulate cyp19a1a transcriptional activity by modulating the binding efficiency of cAMP to its response elements. Compared with in ovary, cyp19a1a showed lower expression in testis but was hypermethylated. Cyp19a1b in female brain weakly expressed before the vitellogenesis stage, but significantly elevated at the maturation stage. In both sexes, it maintained high methylation levels in brain despite the obvious fluctuation of the cyp19a1b expression. This study revealed that DNA methylation plays a key role in establishing cyp19a1a spatiotemporal expression patterns and thus mediates gonadal development in teleosts.

Neurological Safety of Endoscopic Transforaminal Lumbar Interbody Fusion: A Magnetic Resonance Neurography Study.

OBJECTIVE: A magnetic resonance neurography (MRN) study was conducted to assess the neurological safety of endoscopic transforaminal lumbar intervertebral fusion (endo-TLIF). MATERIALS AND METHODS: A total of 56 healthy volunteers (29 men, 27 women; average age, 44 yr; age range, 21-60 yr) were included in the study. Coronal MRN images were collected from L2/L3 to L5/S1. The working triangle, modified working zone, and safest working zone areas, as well as the vertical and horizontal safe operation diameters, were measured. Linear regression analyses were conducted to explore the correlations between general characteristics (sex, age, height, body mass index) and the measured radiographic indicators. RESULTS: MRN can effectively evaluate the operation zone of endo-TLIF. The safest working zone, modified working zone, and working triangle areas were largest at L4/L5 (92.4±23.4, 136±35.6, and 197±41.7 mm 2 , respectively) and smallest at L2/L3 (45.5±12.9, 68.1±19.5, and 92.6±24.4 mm 2 , respectively). The vertical safe operation diameter was large at L4/L5 and L2/L3 (5.34±0.8 and 5.42±0.9 mm, respectively) and smallest at L5/S1 (2.94±0.9 mm). The horizontal safe operation diameter was large at L4/L5 (7.28±1.2 mm) and smaller at L5/S1 and L2/L3 (4.28±1.0 and 4.77±0.8 mm, respectively). CONCLUSIONS: L4/L5 has the lowest risk of nerve injury, and may be the safest level for beginners initiating endo-TLIF in their practice. We recommend that coronal MRN is routinely performed before endo-TLIF to minimize the risk of neurological injury.

Comparative Study between Caspar Cervical Retractor System and Traditional S Retractor in Application on Anterior Cervical Decompression and Fixation.

OBJECTIVE: Although Caspar cervical retractor system (CCRS) is commonly utilized in anterior cervical decompression and fixation (ACDF), most urban hospitals still use both traditional S retractor and CCRS in conventional anterior cervical surgeries. Related data to evaluate the effect are required to be reported. The aim of this study is to compare the efficacy between using the traditional cervical S retractor and CCRS in anterior cervical decompression and fixation ACDF. METHODS: The retrospective study that total 360 patients received ACDF using different retractors (traditional S retractor or CCRS) were enrolled in this study from January 2010 to January 2020. Width change rate of cervical prevertebral soft tissue, throat symptoms, and subjective experiences of the operating surgeons were evaluated by t-test or analysis of variance (ANOVA) respectively. RESULTS: The width change rate of prevertebral soft tissue was significantly higher in the S retractor group than that of the CCRS group both in single segment group (40.9% vs 20.8%, P < 0.05) and double segments group (45.8% vs 25.2%; p < 0.05). In the three segments group, the width change rate of prevertebral soft tissue was higher in the S retractor group than that of the CCRS group, but with no statistical significance (27.3% vs 23.6%; P > 0.05). The incidence rates of dysphagia, dyspnea, and throat discomfort in the traditional S retractor group were significantly higher compared to the CCRS group (P < 0.05), while satisfactory rate of surgeon was higher in the CCRS group (P < 0.05). However, there was no correlation between anterior soft tissue rate and operative time (P > 0.05), as well as the width change rate of anterior soft tissue and the DNRS score (P > 0.05). CONCLUSION: CCRS was superior compared to the traditional S retractor in reducing the postoperative complications and the postoperative fatigue of surgeon. Meanwhile, the width change rate of prevertebral soft tissue was not related to operative time and DNRS score.

Comparison of the Accuracy of Pedicle Screw Placement Using a Fluoroscopy-Assisted Free-Hand Technique with Robotic-Assisted Navigation Using an O-Arm or 3D C-Arm in Scoliosis Surgery.

STUDY DESIGN: Retrospective. OBJECTIVES: To report and compare the application of robotic-assisted navigation with an O-arm or three-dimensional (3D) C-arm-assisted pedicle screw insertion in scoliosis surgery, and compare with free-hand technique. METHODS: One hundred and forty-four scoliosis patients were included in this study. Ninety-two patients underwent robotic-assisted pedicle screw insertion (Group A), and 52 patients underwent freehand fluoroscopy-guided pedicle screw insertion (Group B). Group A was further divided into Subgroup AI (n = 48; robotic-assisted navigation with an O-arm) and Subgroup AII (n = 44; robotic-assisted navigation with a 3D C-arm). The evaluated clinical outcomes were operation time, blood loss, radiation exposure, postoperative hospital stay, and postoperative complications. The clinical outcomes, coronal and sagittal scoliosis parameters and the accuracy of the pedicle screw placement were assessed. RESULTS: There were no significant differences in blood loss and postoperative hospital stay between Groups A and B (P = .406, P = .138, respectively). Radiation exposure for patients in Group A (Subgroups AI or AII) was higher than that in Group B (P < .005), and Subgroup AI had higher patient radiation exposure compared with Subgroup AII (P < .005). The operation time in Subgroup AII was significantly longer than that in Subgroup AI and Group B (P = .016, P = .032, respectively). The proportion of clinically acceptable screws was higher in Group A (Subgroups AI or AII) compared with Group B (P < .005). CONCLUSIONS: Robotic-assisted navigation with an O-arm or 3D C-arm effectively increased the accuracy and safety in scoliosis surgery. Compared with robotic-assisted navigation with a 3D C-arm, robotic-assisted navigation with an O-arm was more efficient intraoperatively.