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.

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.

Objective To modify the posterior procedures for severe thoracolumar fractures. Methods Twenty-one patients of thoracolumbar fractures with over 40% of anterior compression were studied. After reduction and fixation with short-segment pedicle instrumentation was performed, the transpedicular vertebroplasty of the fractured vertebrae with injectable self-setting calcium phosphate cement was carried out under fluoroscopic guidance. All patients were checked with X-ray and CT scanning before and after operation. They were followed up for 4-23 months (average 13 months). Results All patients obtained successful surgery without neurological complications or foreign body response. On CT scanning, the fractured vertebrae were well augmented in 13 cases and insufficiently augmented in 4 cases. Slight extrusion of cement into paravertebral tissue occurred in 4 cases without clinical symptoms. All patients were perfectly recovered without notable correction loss or implant failure during the follow-up. Conclusions Reduction and fixation with short-segment pedicle instrumentation followed by vertebroplasty with injectable self-setting calcium phosphate cement is a promising procedure for severe thoracolumbar fractures.

Objective To investigate the clinical results of percutaneous vertebroplasty(PVP) for symptomatic vertebral hemangioma. Methods Eleven patients(2 males and 9 females) suffered from symptomatic vertebral hemangioma(11 thoracic segment levels and 3 lumbar segment levels) were treated with PVP under DSA or CT guidance. The main goal of this procedure was to relieve hemangioma related pain. All patients were examined with CT scan after intervention and were followed up from 3 to 34 months (average, 15.2 months). Results The procedure was technically successful in all patients, with an average injection amount of 6.3 ml cement per vertebral body. No clinically significant complications were found. There was no epidural leakage, and the 2 paravertebral leakages detected with CT had no clinical importance. Partial or complete pain relief was achieved in all patients associated with improved mobility, and 1 patient experienced transitory worsening of pain followed by significant pain relief. Patients were discharged in 1-4 days (average, 1.5 days) after the procedure. Pain relief was sustained in all patients at the last following-up. Conclusion PVP is a valuable minimal invasive alternative procedure in treatment of symptomatic vertebral hemangioma and provides satisfactory pain relief with less complications.

Objective To analyze the clinical results of percutaneous vertebr oplasty (PVP) for osteolytic spinal tumor. Methods Forty patients with osteolyt ic vertebral metastases or myeloma were selected from Feb. 2000 to Jun. 2003 to undergo percutaneous vertebroplasty. All patients complained of back pain. Among them, 6 cases had radiculopathy, and 1 had paraplegia. Based on CT or MR scanni ng, the posterior vertebral wall was involved in 21 cases. 42 PVP was performed on 59 segment levels under fluoroscopic or CT guidance, including 1 at cervical spine, 29 at thoracic spine, 27 at lumbar spine and 2 at sacrum, and biopsy was performed in 28 cases simultaneously. CT scanning was conducted after interventi on to assess the lesion filling and cement leakage, and all patients were asked to remain lying on bed for 4 hours prior to axial loading. In combination with P VP, radiotherapy, chemotherapy, medicament were administered before or after the intervention. Results The procedure was technically successful in all patients with an average injection amount of 6.5 ml cement per vertebral body. Partial or complete pain relief was achieved in 39 cases, associated with improved mobilit y in 38 cases, the symptoms of patients with radiculopathy and paraplegia were u nchanged. Two cases with severe multiple vertebral destruction underwent PVP at one segment, neither of them experienced improved mobility. In one case, the sev erity of pain was unchanged, while the other experienced partial pain relief for 48 hours. Leakages were detected with CT at 21 levels of 17 cases. 2 of 7 epidu ral leakage produced transitory radicular pain, which were relieved in 6 h and 8 h respectively. 2 with intervertebral foraminal venous leakage, 8 with paravert ebral leakage, and 6 with intra-disc leakage had no clinical symptoms. 37 cases were followed up from 2 to 32 months (average, 8.5 months). Exclusive of poor re sults in 2 patients, pain relief was sustained in 29 cases, and 6 patients exper ienced relapse of pain following partial pain relief, which was related to the d eterioration of tumors. Conclusion PVP of osteolytic spinal tumors is a minimal invasive procedure that provides immediate and stable pain relief with improved mobility. It can be combined with radiotherapy or chemotherapy.