BACKGROUND:Platelet-rich plasma can promote the repair and regeneration of intervertebral disc tissue.Percutaneous transforaminal endoscopic discectomy is widely used in the treatment of lumbar disc herniation.In recent years,more and more scholars have focused on the combined treatment of lumbar disc herniation with the two techniques in order to achieve a better patient prognosis. OBJECTIVE:To investigate the clinical safety and effectiveness of percutaneous transforaminal endoscopic discectomy combined with platelet-rich plasma in the treatment of lumbar disc herniation. METHODS:The clinical data of 58 patients with lumbar disc herniation who met the inclusion and exclusion criteria at Sixth Medical Center of PLA General Hospital from June 2017 to May 2018 were retrospectively analyzed.Among them,29 patients underwent percutaneous transforaminal endoscopic discectomy combined with platelet-rich plasma(observation group),and the remaining 29 patients underwent percutaneous transforaminal endoscopic discectomy only(control group).Visual Analogue Scale score for back and leg pain,lumbar JOA score,and Oswestry Disability Index were evaluated preoperatively,at 3,6,and 12 months postoperatively,and at the last follow-up.Intervertebral space height,nucleus pulposus to cerebrospinal fluid signal strength ratio,and intervertebral disc Pfirrmann grading were measured preoperatively,at 6 and 12 months postoperatively,and at the last follow-up.The modified MacNab criteria were used to assess excellent and good rate of curative effect at the last follow-up. RESULTS AND CONCLUSION:(1)The Visual Analogue Scale score for back and leg pain,JOA score,and Oswestry Disability Index of the two groups postoperatively were significantly improved compared with those preoperatively(P<0.05).Visual Analogue Scale score and Oswestry Disability Index were lower in the observation group than those in the control group at 3 and 6 months postoperatively(P<0.05).The JOA score was higher in the observation group than that in the control group at 3 and 6 months postoperatively(P<0.05).(2)The nucleus pulposus to cerebrospinal fluid signal strength ratio was higher in the observation group than that in the control group at the last follow-up(P<0.05).Pfirrmann grading of the intervertebral discs was better in the observation group than that in the control group(P<0.05).The excellent and good rate was 93%in the observation group and 83%in the control group,and the difference was not statistically significant(P>0.05).(3)These findings indicate that percutaneous transforaminal endoscopic discectomy combined with platelet-rich plasma in the treatment of lumbar disc herniation has satisfactory clinical efficacy and can delay the degeneration of the intervertebral disc to a certain extent.

Objective To investigate the effect of facet joint resection at different ranges under endoscopy on the stability of the cervical spine and provide a biomechanical theoretical basis for clinical surgery.Methods A normal finite element model of the cervical spine C5-6 was established based on CT data,and unilateral facetectomy models with different ranges(0,25％,50％,75％,and 100％)of laminectomy were obtained(Models 1-5)by simulating cervical endoscopic surgery.The ranges of motion(ROMs)of C5-6 and the von Mises stresses of the discs for the models in each group were compared and analyzed.Results Except for flexion,Models 1 and 2 showed insignificant changes in ROMs and disc von Mises stresses in each direction compared with those of the normal model.Model 3 showed a noticeable increase in ROMs and disc von Mises stresses in each direction compared with those of the normal model:ROMs under flexion,extension,left lateral bending,right lateral bending,left rotation,and right rotation increased by 27％,4％,3％,13％,5％,and 16％,respectively,and von Mises stresses increased by 32％,4％,2％,5％,9％,and 5％,respectively.Models 4 and 5 exhibited a significant increase in the ROMs and disc von Mises stresses in each direction compared to the normal model.For Model 4,ROMs were increased by 27％,14％,6％,24％,7％,167％,and von Mises stresses were increased by 33％,13％,3％,32％,10％,130％.For Model 5,ROMs were increased by 27％,17％,6％,25％,7％,167％,and von Mises stresses were increased by 33％,29％,8％,33％,12％,138％.Conclusions As the range of unilateral facetectomy increased,cervical ROM and disc von Mises stress extremum gradually increased.The cervical spine shows a significant ROM increase and stress changes when facet joint resection on one side exceeds 1/2.More than 1/2 of the facet joint should be preserved during surgery to avoid medical instability.

BACKGROUND:In clinical application,simple interspinous fixation without additional interbody fusion has similar fixation effects to pedicle screw and rod fusion internal fixation,and can effectively reduce the range of motion of the responsible segment and the stress of the articular process.However,after simple placement of the new interspinous fusion fixation device BacFuse,the stress at the root of the spinous process is relatively concentrated,and the spinous fracture is prone to occur.If an intervertebral fusion cage is inserted in conjunction with interspinous fixation,Von Mises stress can theoretically be dispersed to reduce the risk of spinous fracture.However,there are few studies on biomechanics and finite element analysis. OBJECTIVE:To observe the biomechanical stability of interspinous fixation-assisted endoscopic interbody fusion in the treatment of severe lumbar spinal stenosis. METHODS:The normal finite element model M0 of the L4-L5 segment of the lumbar spine was established by Mimics,Geomagic,Solidworks,and ANSYS software based on the lumbar CT images of a 26-year-old adult male volunteer excluding spinal diseases.On the basis of M0,the immediate model M1 after endoscopic decompression combined with interbody fusion,the interspinous fixation device(BacFuse)model M2 after endoscopic decompression,and the interspinous fixation(BacFuse)model M3 after endoscopic-assisted interbody fusion were established.The same stress was applied to the upper surface of the L4 vertebral body in the four groups,and the lower surface of the L5 vertebral body was fixed and supported.The range of motion and the extreme Von Mises stress of the endplate bone and the posterior ligament complex of the vertebral body were analyzed under six working conditions of flexion,extension,left/right bending,and left/right rotation. RESULTS AND CONCLUSION:(1)Compared with model M0,the range of motion value of model M1 increased significantly under six working conditions.Model M2 and model M3 had a significant reduction in range of motion.(2)Compared with model M0,the maximum stress of the vertebral body in model M1 did not change significantly under the six working conditions.The maximum stress at the rear of the M2 vertebral body increased significantly.(3)Compared with model M1,the maximum stress of model M3 did not change significantly under the six working conditions.Compared with model M2,the maximum stress of model M3 decreased significantly.(4)Compared with the model M0,the extreme Von Mises stress of the L4 and L5 endplates of the model M1 was significantly increased.The extreme Von Mises stress in L4 and L5 endplates of models M2 and M3 decreased slightly.Compared with model M1,the Von Mises stress of the bone under the L4 and L5 endplate of models M2 and M3 was significantly reduced.(5)It is concluded that the implantation of BacFuse can effectively reduce the bone stress under the endplate during simple interbody fusion,decrease the risk of cage subsidence,diminish the risk of facet joint fracture on the decompression side,and provide a good stable environment for interbody fusion.The placement of an intervertebral fusion cage can reduce the stress of the root of the spinous process,which is beneficial to decrease the risk of fracture of the root of the spinous process.