ABSTRACT
BACKGROUND:As a leading technique in the treatment of primary stenosis by posterior spinal endoscopy through unilateral approach and bilateral decompression using single channel endoscopy,the long-term efficacy needs to be further observed.There are few reports on the scope of intraoperative resection and few relevant studies on biomechanics and finite element analysis. OBJECTIVE:A three-dimensional finite element model was established to evaluate the effects of bilateral lumbar canal decompression under a one-hole split endoscope on lumbar range of motion and intradiscal pressure,to provide suggestions for clinical operation and theoretical basis for further clinical research. METHODS:A complete L3-L5 vertebral body model was reconstructed by CT images of nine healthy volunteers,which was used as the preoperative model M1.The simulated surgical resection range of L4-L5 was performed,and 1/4,1/3 and 1/2 of bilateral facet joints were removed respectively to obtain models M2,M3 and M4.The range of motion and the maximum Von Mises stress of the four models were compared in the six directions of forward bending,backward extension,left and right bending,and left and right rotation. RESULTS AND CONCLUSION:(1)The L3-L5 finite element model established in this study was effective,and the range of motion was within the range of previous solid studies under six motion states.(2)Compared with the M1 model,the L4-L5 lumbar spine range of motion increased with the increase of resection range in M2 with M3 and M4 models under forward bending,left and right bending and left and right rotation loading,and the difference was significant(P＜0.05).Under posterior extension loading,there was no significant difference in lumbar range of motion between M1 and M2(P＞0.05),but there was a significant difference of M1,M3 and M4(P＜0.05).(3)The range of motion of the L3-L4 lumbar spine had no significant change with the increase of bilateral facet arthrotomy(P＞0.05).(4)There was a significant difference in the maximum value of L4-L5 Von Mises between M1 and M2(P＜0.05),and there was a significant difference in the maximum value of L4-L5 Von Mises between M1 and M3,M4(P＜0.01),and the maximum value of L4-L5 lumbar von Mises increased with the increasing range of bilateral facet joint resection.Resection of more than 1/3 was particularly obvious.(5)The maximum value of Von Mises in the L3-L4 lumbar spine was increased with the increase of the resection range under forward bending,left and right bending and left and right rotation loading and the difference was significant(P＜0.05).(6)The results exhibited that the L4-L5 lumbar motion and intervertebral disc pressure increased with the increase of the excision range.Intervertebral disc pressure at L3-L4 increased with the increased extent of excision,but the lumbar range of motion was not significantly affected.In conclusion,the stability of the operative segment may be affected by the increase in the scope of facet joint resection.Although the immediate stability of adjacent segments is not affected,it may accelerate disc degeneration.
ABSTRACT
The management of symptomatic lumbar synovial cysts (LSC) is still a matter of debate. Previous systematic reviews did not stratify data according to different treatment techniques or incompletely reported comparative data on patients treated with lumbar posterior decompression (LPD) and lumbar decompression and fusion (LDF). The aim of our study was to compare LPD and LDF via a systematic review and meta-analysis of the existing literature. The design of this study was in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The review questions were as follows: among patients suffering from symptomatic lumbar synovial cysts (population) and treated with either posterior lumbar decompression or posterior decompression with fusion (intervention), who gets the best results (outcome), in terms of cyst recurrence, reoperation rates, and improvement of postoperative symptoms (comparison)? The search of the literature yielded a total of 1218 results. Duplicate records were then removed (n = 589). A total of 598 articles were screened, and 587 records were excluded via title and abstract screening; 11 studies were found to be relevant to our research question and were assessed for eligibility. Upon full-text review, 5 were excluded because they failed to report any parameter separately for both LPD and LDF. Finally, 6 studies for a total of 657 patients meeting the criteria stated above were included in the present investigation. Our analysis showed that LDF is associated with better results in terms of lower postoperative back pain and cyst recurrence compared with LPD. No differences were found in reoperation rates and complication rates between the two techniques. The impact of minimally invasive decompression techniques on the different outcomes in LSC should be assessed in the future and compared with instrumentation techniques.
ABSTRACT
OBJECTIVE: Since the 1970s, the operating microscope (OM) has been a standard for visualization and illumination of the surgical field in spinal microsurgery. However, due to its limitations (e.g., size, costliness, and the limited movability of the binocular lenses, in addition to discomfort experienced by surgeons due to the posture required), there are efforts to replace the OM with exoscopic video telescopes. The authors evaluated the feasibility of a new 3D exoscope as an alternative to the OM in spine surgeries. METHODS: Patients with degenerative pathologies scheduled for single-level lumbar or cervical spinal surgery with use of a high-definition 3D exoscope were enrolled in a prospective cohort study between January 2019 and September 2019. Age-, sex-, body mass index-, and procedure-matched patients surgically treated with the assistance of the OM served as the control group. Operative baseline and postoperative outcome parameters were assessed. Periprocedural handling, visualization, and illumination by the exoscope, as well as surgeons' comfort level in terms of posture, were scored using a questionnaire. RESULTS: A 3D exoscope was used in 40 patients undergoing lumbar posterior decompression (LPD) and 20 patients undergoing anterior cervical discectomy and fusion (ACDF); an equal number of controls in whom an OM was used were studied. Compared with controls, there were no significant differences for mean operative time (ACDF: 132 vs 116 minutes; LPD: 112 vs 113 minutes) and blood loss (ACDF: 97 vs 93 ml; LPD: 109 vs 55 ml) as well as postoperative improvement of symptoms (ACDF/Neck Disability Index: p = 0.43; LPD/Oswestry Disability Index: p = 0.76). No intraoperative complications occurred in either group. According to the attending surgeon, the intraoperative handling of instruments was rated to be comparable to that of the OM, while the comfort level of the surgeon's posture intraoperatively (especially during "undercutting" procedures) was rated as superior. In cases of ACDF procedures and long approaches, depth perception, image quality, and illumination were rated as inferior when compared with the OM. By contrast, for operating room nursing staff participating in 3D exoscope procedures, the visualization of intraoperative process flow and surgical situs was rated to be superior to the OM, especially for ACDF procedures. CONCLUSIONS: A 3D exoscope seems to be a safe alternative for common spinal procedures with the unique advantage of excellent comfort for the surgical team, but the drawback is the still slightly inferior visualization/illumination quality compared with the OM.
