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BACKGROUND:Minimally invasive endoscopic decompression is currently used in the treatment of lumbar spinal stenosis, but there are few studies on the scope of precise laminectomy under the microscope. OBJECTIVE: To explore the influence of precise decompression with different laminectomy zones on lumbar range of motion and stress distribution using the entire degenerative lumbar finite element model. METHODS: A patient with lumbar spinal stenosis was randomly selected. Based on CT data, the lumbar L4-5 segment finite element model (M1) was established using relevant biomechanical software, and the validity was verified. After that, the finite element simulation of fully endoscopic precisely laminectomy decompression operation was performed. Combined with pathological classification of lumbar spinal stenosis, personalized laminectomy decompression aiming at different L4-5 segment stenosis was established, specifically including L4 lamina margin and partial facet joint resection model (M2), L5 lamina margin and partial facet joint resection model (M3), L4/5 lamina margin and partial facet joint resection model (M4), M4+"Over-the-Top" contralateral partial facet joint resection model (M5), and L4/5 lamina margin and over 50% facet jointresection model (M6). The same boundary loading was applied to the various finite element models. The lumbar range of motion and equivalent stress of intervertebral discs were compared under six conditions including flexion, extension, left and right flexion, left and right rotation. RESULTS AND CONCLUSION: (1) Compared with the entire M1 model, ranges of motion of M2, M3, M4 and M5 models were similar under various conditions, but range of motion of M6 model was significantly increased to 151 %-264% scope, especially in the extension and rotational conditions. (2) In terms of the equivalent stress of disc, the M2, M3, M4 and M5 models showed no obvious increasing trend at the anterior, left and right regions under various working conditions. The largest increase of the equivalent stress at posterior and middle disc regions was 53% maximally, but with no significant stress concentration. However, the equivalent stress in total disc regions showed a significant increasing trend in M6 model, especially in flexion condition with the maximum three times of M1 model. (3) Results suggest that extensive laminectomy can significantly affect the stability of the lumbar spine, with the intervertebral disc stress increase at the corresponding segment which is more likely to accelerate segmental degeneration. Minimally invasive endoscopic decompression is precise and controllable. The personalized decompression schemes can be adopted for different types of lumbar spinal stenosis to ensure the surgery effect and effectively maintain the biomechanical characteristics of the segments.
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BACKGROUND: Minimally invasive endoscopic decompression is currently used in the treatment of lumbar spinal stenosis, but there are few studies on the scope of precise laminectomy under the microscope. OBJECTIVE: To explore the influence of precise decompression with different laminectomy zones on lumbar range of motion and stress distribution using the entire degenerative lumbar finite element model. METHODS: A patient with lumbar spinal stenosis was randomly selected. Based on CT data, the lumbar L4-5 segment finite element model (M1) was established using relevant biomechanical software, and the validity was verified. After that, the finite element simulation of fully endoscopic precisely laminectomy decompression operation was performed. Combined with pathological classification of lumbar spinal stenosis, personalized laminectomy decompression aiming at different L4-5 segment stenosis was established, specifically including L4 lamina margin and partial facet joint resection model (M2), L5 lamina margin and partial facet joint resection model (M3), L4/5 lamina margin and partial facet joint resection model (M4), M4 + "Over-the-Top" contralateral partial facet joint resection model (M5), and L4/5 lamina margin and over 50% facet jointresection model (M6). The same boundary loading was applied to the various finite element models. The lumbar range of motion and equivalent stress of intervertebral discs were compared under six conditions including flexion, extension, left and right flexion, left and right rotation. RESULTS AND CONCLUSION: (1) Compared with the entire M1 model, ranges of motion of M2, M3, M4 and M5 models were similar under various conditions, but range of motion of M6 model was significantly increased to 151%-264% scope, especially in the extension and rotational conditions. (2) In terms of the equivalent stress of disc, the M2, M3, M4 and M5 models showed no obvious increasing trend at the anterior, left and right regions under various working conditions. The largest increase of the equivalent stress at posterior and middle disc regions was 53% maximally, but with no significant stress concentration. However, the equivalent stress in total disc regions showed a significant increasing trend in M6 model, especially in flexion condition with the maximum three times of M1 model. (3) Results suggest that extensive laminectomy can significantly affect the stability of the lumbar spine, with the intervertebral disc stress increase at the corresponding segment which is more likely to accelerate segmental degeneration. Minimally invasive endoscopic decompression is precise and controllable. The personalized decompression schemes can be adopted for different types of lumbar spinal stenosis to ensure the surgery effect and effectively maintain the biomechanical characteristics of the segments.
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BACKGROUND: The effective treatment of lumbar spinal stenosis with total endoscopic decompression is a breakthrough frontier technology. Compared with open surgery, it has the characteristics of fewer traumas, controllable operation, and fewer complications, but it reported less in finite element biomechanics. OBJECTIVE: To establish a finite element model of full endoscope lumbar fenestration and to investigate the effects of decompression range and nucleus pulposus removal on lumbar range of motion and stress distribution of disc. METHODS: CT scan data of a case of L4-5 segmental lumbar spinal stenosis were collected and imported in Mimics 20.0 software. A finite element model M of L4-5 lumbar spinal stenosis in degenerative lumbar spine was established. The model M was imported into 3-matic for surgical simulation, i.e., unilateral disc resection of the small joints 1/2 and 1/4 model M1, bilateral joints 1/2 and 1/2 resection of intervertebral disc model M2, and unilateral disc and articular process of 1/4 model M3. In the ANSYS software, the mechanical comparative analysis was conducted in four kinds of models under six working conditions of the same pure couple moment, including forward bending, backward extension, left bending, right bending, left rotation and right rotation, and the same load of the intervertebral disc. RESULTS AND CONCLUSION: (1) Compared with the spinal M model, the range of motion of M1 model was similar under six working conditions, but the range of motion of M2 and M3 was significantly increased than that of M, especially under the left/right flexion and forward/backward flexion working conditions, which was 130%-200% of the overall activity of M model. (2) In terms of the stress of intervertebral disc, M1 model showed no obvious upward trend of the effect force in the posterior region, central region and right region of intervertebral disc under various working conditions. The equivalent stress in the left region and front region of intervertebral disc increased to a maximum of 63%, but there was no significant stress concentration. In the M2 and M3 models, the equivalent stress of intervertebral discs in all regions showed a significant increased trend. (3) Endoscopic minimally invasive surgery is accurate and controllable for different types of lumbar spinal stenosis decompression surgery. The resection of facet joints and the removal of nucleus pulposus by less than 1/2 have little influence on the biomechanical stability of the corresponding segments. The successful and reliable finite element modeling of lumbar lamina fenestration can provide an important method and basis for the follow-up biomechanical study of lumbar surgery.
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Objective To analyze the effectiveness of laminectomy decompression compared with vertebral lamina decompression combined with lumbar fusion in Degree I spondylolisthesis and spinal canal stenosis. Methods PubMed, Science Direct Online, Springer, CNKI, Wan Fang and VIP were retrieved to collect relevant randomized controlled trials( RCT) . According to inclusion and exclusion criteria,two researchers screened literatures, extracted data and evaluated quality. RevMan5. 0 software was used for Meta analysis. A total of 11 RCT were included,with a total of 1684 patients. Meta analysis showed that compared with the simple laminectomy group,the VAS score of lumbar pain in the lumbar fusion group at 1 years after operation decreased ( MD and 95％CI:-1. 20(-1. 57--0. 83) ,P<0. 05) ,and the VAS score of the 1 year postoperative leg pain in the lumbar fusion group decreased(MD and 95％CI:-0. 88(-1. 32- -0. 44),P<0. 05),the excellent rate of lumbar fusion group at 2 years after operation was higher( OR and 95％CI:1. 65( 1. 13-2. 41) ,P<0. 05) . There was no significant difference in postoperative complications and lumbar spondylolisthesis at 1 years after operation. Conclusion In long term, compared with decompression alone, vertebral lamina decompression combined with lumbar fusion has more ideal effectiveness in the treatment.
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Objective: To explore the safety of ultrasonic osteotome used in posterior cervical laminectomy decompression surgery and its effect on surgical outcome. Methods: A clinical data of 52 patients with ossification of posterior longitudinal ligament of cervical spine (C-OPLL) undergoing posterior cervical laminectomy decompression and fusion (PCLDF) between April 2013 and April 2017 was retrospectively analysed. The patients were divided into two groups according to whether using the ultrasonic osteotome during operation: group A (20 cases, ultrasonic osteotome group) and group B (32 cases, traditional gun-clamp decompression group). There was no significant difference in gender, age, body weight, height, preoperative hemoglobin, and Japanese Orthopedic Association (JOA) score between the two groups ( P>0.05). The operation time, intraoperative blood loss, postoperative drainage volume, hospitalization time, complications, hemoglobin at 1 day after operation, and JOA score at 6 months after operation were recorded and compared between the two groups, and the improvement rate of JOA was calculated. Results: The operation time and intraoperative blood loss in group A were significantly less than those in group B ( P0.05). The hemoglobin of group B was slightly higher than that of group A at 1 day after operation, but there was no significant difference between the two groups ( t=-1.260, P=0.214). All the patients were followed up 6-10 months (mean, 7.6 months). No serious complications such as C 5 nerve paralysis, dural tear, infection, epidural hematoma, deep venous thrombosis, pulmonary embolism, transfusion allergy, or shock occurred during and after operation. The JOA scores of the two groups were significant improved at 6 months after operation when compared with preoperative scores ( P0.05). Conclusion: Compared with the traditional gun-clamp decompression, the effectiveness of PCLDF in treatment of C-OPLL by using ultrasonic osteotome is comparable, but the latter can effectively reduce the operation time and blood loss.
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Objective: To analysis the efficacy of percutaneous transforaminal endoscopic discectomy on the treatment of lumbar disc herniation. Methods: A total of 86 patients with lumbar disc herniation were randomly divided into experimental and control groups. They were given percutaneous transforaminal endoscopic discectomy and laminectomy decompression therapy. The clinical effi?cacy, VAS, JOA, Lehmann score and other relevant circumstances before and after surgery were compared. Results: The total effec?tive rate in the experimental group was higher than that in the control group. Postoperative JOA score and Lehmann score were higer than those in the control group. VAS scores were lower than that in the control group, bleeding amount, incision size, length of hospi?talization, complication rates lower than that in the control group, the differences were statistically significant ( P<0?05) . But there was no signifiant difference in operative time ( P>0?05) . Conclusions: Percutaneous transforaminal endoscopic discectomy for lum?bar disc herniation can improve clinical outcomes and reduce pain, improve function, reduce blood loss, shorter hospital stay and pro?mote postoperative recovery, reduce complications. It is worth further clinical application.