Pedicle Cortical Bone Trajectory Screw Technology Research In Chinese People For The Treatment Of Lumbar Degenerative Disease

ObjectiveThe safety assessment of pedicle cortical bone trajectory screw technology(CBT)in Chinese,not only confirm the feasibility of its application,but also study the small incision CBT technique on the back of the muscle damage,and finally acknowledge the value of the minimally invasive technology.To establish the standard of lumbar CBT screw fixation for Chinese People,to provide scientific basis for the next step in designing CBT screws for lumbar,and providing theoretical basis and technical support for CBT screw technique of lumbar degenerative diseases in China.BackgroundClinically,the traditional pedicle screw fixation technique is a common method for the treatment of lumbar degenerative diseases by spinal surgery.The biomechanical strength of the traditional pedicle screw fixation mainly depends on the tightening force of the screw and the cancellous bone.In the osteoporosis patients,the strength of the screw-bone interface is significantly decreased,the screw loosening and prolapse are the most common reasons,By extending the spinal fixation segment,the use of bone cement to increase the fixation strength of pedicle screw,can improve the stability of patients with osteoporosis fixation.However,these methods have some drawbacks.For example: the use of bone cement in the presence of high temperature release,monomer toxicity,bone cement fatigue fracture and other issues;Extending the spinal fixed segment to increase the cost of surgery,time,bleeding and complications.Biomechanical experiments found that vertical implantation of pedicle screw to get a more solid fixation effect.Under the guidance of this theory,Santoni proposed a new pedicle screw fixation technique,the cortical bone Trajectory screw(CBT,Cortical Bone Trajectory)fixation technique.The direction of the staple direction is on the sagittal plane from the tail toward the head,from the inside to the outside in the horizontal plane.CBT screw and implant point dorsal cortical bone,posterior medial pedicle wall,anterolateral pedicle wall and vertebral wall surface four points of contact,which greatly increased the screw and cortical bone contact.In patients with osteoporosis,the bone mass of the cancellous bone is much higher than that of the cortical bone.The CBT screw fixation technique achieves stronger fixation through the four-point contact with the cortical bone.This study suggests that CBT is well suited for internal fixation in patients with lumbar degenerative disease and with osteoporosis.MethodsThis study was divided into three parts:CBT technique was used to study the safety of lumbar degenerative disease、feasibility study and the minimally invasive value of small incision CBT technique.In the first part,36 patients with lumbar degenerative diseases were treated with CBT technique from January 2014 to October 2016,the vascular,neurological and visceral injury complications of all patients were observed during and after operation,and the number of CBT screws in the pedicle was evaluated.The number of screws penetrating through the medial wall,lateral wall and vertebral anterior wall of the pedicle was recorded.In the second part,36 patients was divided into two groups: which were selected from January 2014 to July 2015,The patients in the treatment group were treated with conservative treatment for 30 patients with osteoporotic lumbar degenerative disease.:18 cases using traditional pedicle screw fixation technique,12 cases were treated with CBT screw fixation technique,the recovery、operation time、blood loss and vas score、JOA Ratings and improvement rate before and after operation were observed in two groups.The third part was divided into two groups: 47 patients in group A were treated with traditional pedicle screw fixation and 36 patients in group B were treated with CBT technique,the operation time、intraoperative blood loss、preoperative and postoperative serum creatine kinase(CK)levels as well as preoperative and postoperative VAS scores、 ODI scores were recorded.ResultsThe first part of the study results: Totally 168 lumbar pedicle CBT screws were implanted in 36 patients,L1 was implanted only 2 CBT screws,which was the least;L5 was implanted the largest number of CBT screws,which was 78.In the stapling process,there were 3 cases of 6 screws,the CBT screws were changed to the traditional pedicle screw fixation,There were 5 cases of 9 screws,the CBT screw position was found by the C-arm X-ray machine poorly changed to the traditional pedicle screw.All patients have no blood vessels 、 nerves 、 visceral injury and infection and other complications after surgery.All the 36 patients adopted lumbar CT scan,which penetrated the largest number of lateral wall of the pedicle,21 screws totally,the maximum penetration distance was about 5mm;penetrate the anterior arch of the arch was about 13 screws,the maximum penetrate distance was about 4.6mm;penetrate the pedicle of the medial wall of the smallest number,only 3 screws,and the penetration distance of less than 2mm.The second part of the study results: all 30 patients were improved symptoms,postoperative JOA and VAS scores were significantly improved between the two groups in the operation time and bleeding.JOA score and VAS score difference was not statistically significant.The third part of the study results: B group of patients in this study using CBT fixation technology to avoid the excessive cleavage and long stretch of the cleft muscle and paraspinal soft tissue,the amount of bleeding,postoperative drainage were significantly less than A group of patients,and can do a small incision to complete the operation,and B group of patients with postoperative CK levels were significantly lower than the A group of patients,than the A group of patients to return to normal levels,and B group were followed up Time points VAS score and ODI score were lower than group A.Conclusions(1)This study combined with the clinical case to analysis and value CBT screw fixation technology in the application of Chinese people,and combined with previous studies which proved CBT technology is more secure and reliable,and have good feasibility for the indications.To achieve minimally invasive in a certain extent and there is a great value of minimally invasive.(2)In the first part of this study,it was found that the use of CBT technique for lumbar vertebroplasty was more safe and reliable in the treatment of lumbar degenerative disease.(3)The second part of this study found that the use of CBT screw technique for lumbar fixation can increase the contact surface with the cortical bone and have firmness and other advantages,early efficacy satisfactory.(4)The third part of this study found that: the application of CBT screw technique for lumbar internal fixation,its’ nearer screw point can avoid a wide range of muscle stripping and tissue resection and postoperative patients have lower back muscle inflammation than the traditional pedicle screw and also can do small incision,there is a certain minimally invasive value.