At present, percutaneous transforaminal endoscopic discectomy (PTED) has been rapidly developed in our country, showing that spine surgery has entered the era of the minimally invasive spine surgery, but we must clearly recognize the learning curve and the difficulties in the operation. According to the specific needs of patients, safe and effective should be premised, and take the most convenient and effective measures, avoid the blind pursuit of new technology and high technical difficulty, avoid increasing the surgical indications and avoid exaggeration effect. We must have a solid foundation of spinal surgery and seriously standardized training. We must establish reasonable access and training system, which can avoid detours, shorten the learning curve, and let the transforaminal endoscopic minimally invasive techniques have a healthy and stable development.

Nowadays, percutaneous transforaminal endoscopic discectomy (PTED) and microscopic endoscopic disecto?my (MED) are common techniques for lumbar disc herniation and stenosis. Similar to traditional fenestration, MED is per?formed via interlamina approach, and is suitable for most cases of lumbar disc herniation and stenosis. And the mobile MED (MMED) used by author is beneficial to expose and manipulation. The PTED is performed during normal saline irrigation via natural transforaminal or interlamina approach. Compared to MED, PTED is less invasive and has relatively limited operat?ing range, which depends on accurate puncture. MED and PTED have their particular standard and skills, and their indica?tion is crossed and complementary. These two techniques can be selected according to specific conditions of patients.

Compressive cervical myelopathy (CCM) is a common disease of spinal surgery. Various kinds of reasons such as herniation of cervical disc and ossification of the posterior longitudinal ligament (OPLL) lead to spinal canal stenosis, thereby compressing the spinal cord, and a series of neurological symptoms are caused. Currently, posterior cervical expansive open-door laminoplasty (PCEOLP) is widely used for cervical decompression in patients with CCM involving three or more levels. This operation can expand the spinal canal while preserving the posterior structures of the cervical spine, and non-neurological complications are relatively rare. However, there are characteristic complications to this procedure such as nerve root palsy, axial neck pain, and loss of range of motion (ROM). Various modified techniques of PCEOLP have been developed to reduce postoperative complications. In this review, clinical research progress of PCEOLP in recent years is summarized, mainly focusing on internal fixation of materials and methods, operative approach, cervical decompression level, combined application of different surgical procedures, opening size and application of new technologies.

The intervertebral disc disease is a group of clinical diseases with complex etiology, various clinical symptoms and poor conservative treatment effect. The traditional treatment methods include conservative treatment, local injection and open surgery. In recent years, minimally invasive spine surgery has made great progress and development, and its clinical effect has been fully affirmed. Coblation nucleoplasty (CN) has been mainly used in the treatment of contained disc herniation since it has been used in clinical treatment. Its application is not favorable because of narrow indications, uncertain clinical efficacy and other reasons. At present, the application of CN in the intervertebral disc diseases has been reported in many literatures, and its working principle, operation safety, indications and efficacy have been analyzed and extended. Those literatures play an important role in its clinical application. Therefore, in this paper, the application status of CN in the intervertebral disc diseases is reviewed.

Objective To analyze the results and indications of anterior, posterior or combined surgery for thoracolumbar burst fractures. Methods A retrospective review of surgically managed thoracolumbar burst fractures from 1998 to 2003 was performed. There were 76 males and 13 females, and the age of the patients were from 17 to 51 years with an average of 36.8 years. The fractures were located at T11 in 10, T12 in 21, L1 in 29, L2 in 18 and L3 in 11. According to Magerl classification, type A fractures were 68, and type C were 21. Of the 89 patients, 41 received posterior surgeries, 40 anterior surgeries, and 8 combined anterior and posterior surgeries. Operative notes, preoperative and postoperative neurological status, radiographs, CT scans, and follow-up records were reviewed. Results All of the 89 cases had successful surgery. Seventy-eight patients were followed-up for 6 to 48 months (average 12 months). Neurological status improved at least 1 ASIA grade in all of the 65 patients who had preoperative incomplete paraplegia. In the posterior surgeries, pedicle screws broken in 2 cases, deep infection in 1 case which was cured after debridement. The correction of anterior vertebral body height and Cobb's angle averaged 9.4 mm and 14.8? postoperatively, and the correction loss averaged 0.5 mm and 7.5? respectively at 6 months after surgery. And the correction loss was most evident at the above disc spaces, then the below disc spaces. In the anterior surgeries, leakage of cerebrospinal fluid in 2 cases which cured with dressing change, the other cured after debridement, implant removal and posterior fixation. The spinal canal was enlarged, and the spine recovered normal curvature. No evident correction loss, pseudoarthrosis or implant failure was noted at follow-up. Conclusion The choice of anterior, posterior or combined surgery for thoracolumbar burst fractures depends on neurological status and column stability. The vertebral compression, canal encroachment, posterior column stability and concomitant displacement should be considered in the choice of appreciate surgical approach.

BACKGROUND:Bone marrow mesenchymal stem cells as non-hematopoietic stem cells from the mesoderm mostly come from the bone marrow, which have a stronger self-renewal ability, multilineage differentiation ability and low immunogenicity and are easy to receive the introduction of foreign genes. Therefore this kind of cells have become the research hotspot in recent years. OBJECTIVE:To summarize the latest clinical application and advancement of bone marrow mesenchymal stem cels in the treatment of various diseases. METHODS: PubMed (http://www.ncbi.nlm.nih.gov/PubMed) and SinoMed (http://www.sinomed.ac.cn/zh/) databases were searched by the first author using the keywords of bone marrow mesenchymal stem cells, therapy to identify the relevant articles published in English and Chinese, respectively, from 2011 to 2016. After excluding repetitive, irrelevant or Meta-analysis literatures, we enrolled 49 literatures for final analysis. RESULTS AND CONCLUSION:Studies on bone marrow mesenchymal stem cells have achieved new grades in the treatment of respiratory system disease, cardiovascular disease, urinary system disease, nervous system disease, liver disease, diabetes mellitus, hematological system disease, autoimmune disease, graft-versus-host disease, motor system disease, although its application has the risk of oncogenicity. Further investigation on the oncogenicity of bone marrow mesenchymal stem cells will be gradually explored, aiming to a better clinical use of bone marrow mesenchymal stem cells.

0.05).2)a.There was no severe side effects related to cement in 20dogs,and no pulmonary embolic necrosis was found in autopsy.Cement leakage was frequent which occupied the spinal canal no mo re than 1/4of the median sagittal dia meter without major neurological complication.The epidural leaks we re related to the vertebral morpholo gy.b.The average peak temperatures were 70.5℃at the core,53.5℃at the in terface,40.8℃at the anterior corte x,and 40.5℃in the spinal canal.The temperature above 50℃lasted for 2.9minutes at the core,and 1.3minutes at the interface.In pathological examination,necrosis of osteocytes was found focally at t he periphery of the cement,and resid ual bone in this area showed signs of acti ve remodeling.3)The procedure was technically successful in all pa-tients,with an average injection am ount of 6.3ml cement per vertebral body.No clinically significant com-plications were noted.The 3slight e pidural leaks,1slight neural foram ina leak,and 5paravertebral leaks detected with CT had no clinical importance.Partial or complete pain relief was achieved in all patients as-sociated with improved mobility,an d 1patient experienced transitory worsening of pain followed by significant pain relief.Patients with vertebra l haemangioma or compression fractu res were discharged in 1-4days(average,1.6days)after the procedure.Of the 26patien ts,22were followed up from 6to 24mon ths(average,13.5months),partial or complete pain relief were sustained in 21cases,the other one experienced relapse of pain following partial pain relief,which was related to the deterioration of the metastases.Con-clusion Minimal invasive PVP is a valuable alternative in the treatment of painfu l vertebral haemangioma,osteoporotic vertebral fractures,and osteolytic metastases or myelom a,providing acute pain relief and ea rly mobilization in appropriate patien ts.[

Objective To analyze the long term results of thoracolumbar burst fractures treated with short segment pedicle instrumentation. Methods Sixty eight cases of thoracolumbar burst fractures fixed with short segment pedicle instrumentation were followed up for at least 5 years (5-13 years, average 8 years). All of them were checked with radiography pre and post operation and before implant removal. At final follow up assessment, all were examined with radiography, 18 cases were checked with CT scan as well. Results 1) Neurological status improved at least 1 Frankel grade in 90.3% of the patients who had preoperative incomplete paraplegia, while no improvement was obtained in those who had preoperative complete paraplegia. Low back pain was evaluated according to Denis Pain Scale, the results showed P1 41 cases (60.3%), P2 24 cases (35.3%), P3 3 cases (4.4%). 2) The shortest distances between the upper and lower pedicle screws tips shortened for 0-6.5 mm (average 2.5 mm) before removal in contrast to that at post operative immediately. Of the 68 cases, nuts loosened in 1 case, pedicle screws loosened in 1 case, bent in 2 cases and broken in 5 cases. Of the 8 cases whose implants were not removed timely, screw broke in 2 cases, and seepage occurred through incision in 2 cases. 3) At final follow up, the correction of anterior vertebral body height averaged 30.5%, and Cobb angle 5.8?, despite a mean correction loss of Cobb angle 12.1?. Correction loss was most evident at the above disc spaces, then the below disc spaces. Correction loss of vertebral body height averaged 1.9% in the anterior, and 6.0% in the middle part. 4) The collapse of vertebral body was most serious in the middle part. The deformity of "codfish vertebrae" occurred in the superior part of vertebrae body in 21 cases, among them the upper adjacent vertebral body sank into the injured body in 5 cases, 3 of whom engendered kyphoses greater than 25?. Evident intra corporeal gaps were found in 16 of 18 patients who were checked with CT, and the gaps communicated with the above disc space. The fractured body could have a deformity of the "cup" after reduction. 5) Degeneration and narrowing of the disc spaces next to fractured vertebrae were very common, and the above space disappeared in 27 cases, while the lower space disappeared in 14 cases. The upper disc space adjacent to fixation levels degenerated in 1 of 8 cases whose implants were not removed timely. Five patients had Cobb angle greater than 20?, three of them had low back pain, and one had mild symptom of nerve compromise. Low back pain was not correlated with degeneration of discs. Conclusion Short segment pedicle instrumentation provides satisfying stability for thoracolumbar burst fractures. It helps physiologic postural contour restoration and facilitates neural recovery, but is associated with relatively high rates of implant failure and correction loss which is most evident at adjacent discs spaces. Deficiency of bone grafting and delayed implant removal are the most probable causes for correction loss.

Objective Short-segment pedicle instrumentation for thoracolumbar burst fracture was known to have a relatively high incidence of failure and correction loss, intracorporeal gap secondary to reduction being probable causes. The purpose of this study was to evaluate the intracorporeal gap after reduction and the biomechanical effect of vertebroplasty on thoracolumbar burst fractures. Methods Six fresh adult thoracolumbar specimens were collected, and 10 segmental specimens (T11-L1, L2-L4, T12-L2) were processed. Burst fracture was created using free-drop test. Then the fractures were reduced and augmented with injectable self-setting calcium phosphate cement. The intracorporeal gap and bone mineral density(BMD) were measured using spiral CT and dual energy X-ray absorptiometry(DEXA) before fracture, after reduction and after vertebroplasty respectively. The stiffness in middle vertebrae and above discs were measured under flexion, extension, lateral flexion and torsion stress before fracture and after augmentation. The ultimate strength against compression was tested in the augmented vertebrae and the integral vertebrae below it. Results Burst fractures were created in eight of ten specimens. 1) There was no evident intracorporeal gap before fracture, which appeared after reduction with average volume of 5.25 cm3 (13.9% of total corporal volume), and it decreased to normal level after vertebroplasty. 2) The BMD was normal in all specimens before fracture, which decreased significantly after fracture reduction, and it was significantly higher after vertebroplasty than that before fracture or after reduction. 3) There was no significant difference of stiffness in vertebrae before fractures and after augmentation. The mean value of ultimate strength against compression in the augmented vertebrae decreased slightly but not significantly in contrast to the vertebrae below it. In contrast to the value before fracture, the stiffness of above discs decreased significantly under flexion and extension stress but not significantly under lateral flexion stress after augmentation, while the stiffness of the specimen decreased significantly under torsion stress. Conclusion 1) Posterior reduction in thoracolumbar burst fracture can not reestablish intact corporeal structure, which may be an important cause of postoperative implant failure and correction loss. 2) Vertebroplasty with injectable self-setting calcium phosphate cement is helpful to reestablish intact corporeal structure, and restore stiffness and strength of the injured corpora nearly to its initial value.