SUMMARY The stab wound of cervical spinal cord is rare in clinic. A four-year boy was encountered a directly posterior stab wound in neck by a knife in an accident. He was sent to hospital with hypovolemia shock. After treatment for hypovolemia shock MRI in cervical spine was performed which showed cervical spinal cord was partly cut from dorsal in C4.At the same time the leakage of cerebrospinal fluid was found near the cervical spine C4.He was treated with operation of decompression with local debridement and ligation hemostasis. After operation he received neuro nutrition drugs and Prednisolone because of neurologic deficit. A 14-month follow-up was made. His neurologic deficit was improved but deformity of cervical kyphosis appeared.

BACKGROUND: The use of interbody cages is rapidly increasing in filed of spinal fusion surgery. The inherent limitations of conventional cages such as cage migration or failure, radiopacity, fusion stress shielding, late-onset inflammation and osteolysis give some impetus for the development of bioresorbable cages. Compared with conventional cages, they show better rigidity and elasticity coefficient, with less interference on the imaging evaluation. OBJECTIVE: To introduce the materials classification and property, animal studies, clinical application, current drawbacks and future directions of bioresorbable fusion cages, and provide objective evidences for the research and clinical application of the cages.RETRIEVAL STRATEGY: The relevant articles published between December 1990 and December 2006 were searched for in Pubmed database by the researchers of this article, with the key words "bioresorbable cages, spine, SCI" in English. A total of 550 articles were selected and reviewed preliminarily by the inclusive standards of: research about materials, animal studies and clinical application of bioresorbable cages. Exclusion criteria: repetitive studies.LITERATURE EVALUATION: The main sources of literatures are researches about materials, animal studies and clinical application of bioresorbable cages. Among the 27 selected articles, 1 is review, while others are clinical or elementary experimental studies. DATA SYNTHESIS: ①Materials: Polylactides becomes the most useful and applied base material for bioresorbable spinal interbody cages; characteristics of bioresorbable materials include crystallinity, average molecular weight, molecular weight distribution (polydispersity), and glass transition temperature. There are also several points to consider in the design of bioresorbable cages such as characters related to degradation, functional degradation rate, intensity of inflammatory response and occupation by other tissues following degradation.②Animal studies: Quadruped can be a valuable model for the study of the spine, but it has its limitations; Researches in vitro are focused on these cages of their degradation characters and maintenance of the spinal elasticity; Researches in vivo consisted of the characters of biomechanics, degradation, fusion and foreign body reactions of these cages.③Clinical application: Bioresorbable cages are satisfactory for the clinical application in the TLIF, PLIF of lumbar operation and the ACDF of cervical operation in short term follow up study.④Bioresorbable cages have their drawbacks, which may bring about the development of related techniques.CONCLUSION:The research and application of bioresorbable cages are at the preliminary stage, but the results that we have got are promising for their further research and clinical application.

BACKGROUND:Scholars are stil looking for ideal bone tissue-engineered scaffolds, and three-dimensional (3D) printing technology is a novel construction method. In the meanwhile, bone extracel ular matrix is becoming a hotspot in osteogenic induction. OBJECTIVE:To construct the polycaprolactone/bone extracel ular matrix scaffold using 3D printing technology and co-culture method, and to detect its osteogenic property. METHODS:216 3D-printed polycaprolactone scaffolds were divided into group A (96 pores, n=72) and group B(48 pores, n=144). Passage 5 bone marrow mesenchymal stem cel s from Sprague-Dawley rats were seeded onto the two kinds of polycaprolactone scaffolds, and the group A was used for alizarin red staining and Masson staining, while the group B for col agen and glycosaminoglycan detection at 1, 2 and 3 weeks of incubation. Afterwards, the scaffolds at 1, 2 and 3 weeks of culture were decel ularized and labeled as groups AE1, AE2, AE3, BE1, BE2 and BE3. Then passage 5 bone marrow mesenchymal stem cel s from Sprague-Dawley rats were seeded onto each scaffold again, and the former three groups underwent alizarin red staining, and the latter three were used for calcium, alkaline phosphatase activity and DNA quantitative analysis at 1, 2 and 3 weeks of culture. RESULTS AND CONCLUSION:Masson staining, glycosaminoglycan and hydroxyproline quantitative analysis showed that the extracel ular matrix on the composite scaffold increased with time. Alkaline phosphatase activity revealed that the composite scaffold had a significantly stronger osteogenic differentiation than the normal polycaprolactone scaffold (P<0.05). Alizarin red staining and calcium quantitative analysis showed that the mineralization of the composite scaffold was more obvious than that of the normal polycaprolactone scaffold (P<0.05), but the total DNA analysis did not differ significantly between scaffolds. These results suggest that the composite scaffold with extracel ular matrix is constructed successful y using the 3D technology and co-culture method and exhibits a better osteoinductivity.

A total of 30 patients with degenerative disc disease underwent posterior lumbar interbody fusion (PLIF) using a B-twin expandable spinal spacer (ESS) at the Department of Orthopedics,First Hospital,Peking University between August 2005 and February 2008 and were retrospectively analyzed.These patients consisted of 14 males and 16 females and averaged 28-72 years old.PLIF was performed at L1/2 in 1 patient,at L2/3 in 1 patient,at L3/4 in 1 patient,at L4/5 in 14 patients,and at L5/S1 in 13 patients.Patients underwent PLIF using simple B-twin ESS (n=8,1 employing single spacer,and 7 a pair of spacers) or B-twin ESS combined with pedicle screw (n=22,17 employing single placer,and 5 a pair of placers).B-twin ESS with a diameter of 9.5-11.0 mm was used in 28 patients and with a diameter of 11.5-13.0 mm in 2 patients.Examinations were carried out before surgery,post surgery,and during follow-up.Clinical symptoms were assessed using a 29-point Japanese Orthopaedic Association (JOA) score rating system.Spinal dysfunction was evaluated using the Oswestry Disability Index (ODI).The intervertebral space height and slippage reduction were measured through X-ray images.Twenty-eight of thirty patients were averagely followed up for 9 months.The excellent and good rate of ODI was 97% post surgery and 100% during follow-up period.The excellent and good rate of JOA was 93% post surgery and 96% during follow-up period.The proportion of intervertebral space height in upper vertebra that averaged 0.29±0.09 before surgery increased to 0.44±0.09 post surgery and stabilized at 0.4±0.09 upon final follow-up.The slippage was 10%-60% of upper vertebra before surgery,0%-40% post surgery,and 0%-30% till final follow-up.No neurological impairment or infection was found.There was 1 patient suffering from dural tear for adherence during decompression,1 patient presenting implant subsidence into the endplate post surgery,and 1 patient exhibiting spacer fragmentation during follow-up period.All outcomes indicate that B-twin ESS is characterized by minimal invasion,short surgery time,and less neurostimulation and provides satisfactory postoperative and follow-up efficiency.Attention should be paid to selecting suitable spacer type according to preoperative and intraoperative measurements.There is a breakage possibility if the spacer is put on one side of the space.To avoid this,sufficient bone graft is essential and two spacers may be put in one vertebra space if necessary.

BACKGROUND:It is a very difficult task to transfer from the animal model of cervical spondylosis to clinical treatment. However, the pathology of cervical spondylosis is not very clear, and the main reason is the lack of an ideal animal model of the experiment.
OBJECTIVE:To review the commonly used modeling methods and evaluate the advantages and disadvantages of different modeling methods through consulting literatures.
METHODS:The key words were“cervical spondylosis, cervical spondylotic myelopathy, cervical spondylotic radiculopathy, vertebroarterial type of cervical spondylosis, animal model”. The first author retrieved Medline and CNKI for studies published from 1991 to 2015 concerning animal experiments or clinical studies on the construction of animal model of cervical spondylosis. Final y, 41 studies were included for reviewing.
RESULTS AND CONCLUSION:There are many methods for the modeling of cervical spondylosis at the present stage, including implantation method, screw insertion method, bal oon compression method, mechanical compression, injection method, spinal suture method and mechanical imbalance method. Each has its advantages and disadvantages. In the study of cervical spondylosis, we should choose the appropriate animal model according to the research purpose. Further research and the establishment of a comprehensive animal model are stil the goal of efforts.

BACKGROUND:With the development of atlantoaxial morphology, applied anatomy and biomechanics, pathogenesis, diagnosis and treatment of atlantoaxial instability have attracted more and more attention. However, the development of effective fixation for atlantoaxial instability is relatively late, so scholars al over the world have made numerous studies. OBJECTIVE:To compare biomechanical functions of different fixations through atlantoaxial posterior approach, and to assess its stability. METHODS:We retrieved recent studies on comparative biomechanical evaluation and its primary clinical application of different posterior approaches in repair of atlantoaxial instability, and conducted a retrospective analysis by measuring the three-dimensional range of movement in normal atlantoaxial complex and atlantoaxial instability models. This analysis evaluated the stability of different fixations under normal three-dimensional atlantoaxial movement, and provided a biomechanical basis for reasonable fixator selection.
RESULTS AND CONCLUSION:Atlantoaxial posterior fixation included Gal ie wire fixation, Brooks fixation, Apofix and Halifax vertebral plate hook fixation, screw fixation through joint and atlantoaxial pedicle nail/rod fixation. Gal ie technique contributes to the reduction of anterior semiluxation, but its mechanical stability is poor. Brooks technique has strong rotation and stretch forces. Apofix and Halifix vertebral plate hook device provides strong anti-rotation and anti-antelocation strength, and is more stable than Gal ie technique in mechanics. The biomechanics of screw fixation through joint was better than wire technique and Halifax. The screw fixation avoids occipitocervical fusion, and has a high requirement to instal ation. When an internal fixator was selected, immediate cervical vertebra stability should be provided to protect spinal cord functions. Upper neck functions should be maintained to reach reduction and maintenance of occipital bone, atlas and axis. A suitable fixation method should be selected for each patient.

BACKGROUND: Scoliosis is a complex three-dimensional plane deformity, including lateral bending on the coronal plane, before physiological kyphosis reduction or increase in the sagittal plane, the rotational deformity of the spine in the axial plane. The method of ful decompression, maximum reconstruction of spinal balance in coronal and sagittal plane, long-segmental fixation and short-segmental fusion is the more ideal orthopedic method for degenerative scoliosis. OBJECTIVE: To analyze the characteristics of scoliosis fixation system. METHODS: The articles about scoliosis fixation system were retrieved from PubMed database, Chinese Journal Ful -text database from 1999 to 2015 by the first author using computer. “Scoliosis, Internal Fixation, Three-dimensional Correction” were taken as the search terms in English and Chinese. Total y 163 relevant articles were retrieved, and eventual y 34 articles met the inclusion criteria. RESULTS AND CONCLUSION: With the development of fixation materials, the spinal fixation system which was designed based on three-dimensional orthopedic concept of spine is a dynamical y developed system. The goal is to restore the balance of spine in three dimensions as comprehensive as possible. At present, the general spinal system within very broad application includes TSRH spinal fixation system, ISOLA spinal internal fixation system, Moss Miami spinal fixation system, CD Horizon spinal internal system and China Great Wal spinal fixation system. Spinal fixation system possesses three-dimensional orthopedic capability, and can correct the spinal deformity in coronal and sagittal plane, and biomechanics is reasonable, fixed and reliable. Bone grafting material is the key factor of preventing breakage of internal fixation, screw extraction and other complications. Compared with such bone grafting materials made of autologous bone, al ograft bone and xenograft bone, artificial bone can shorten the orthopedic time and reduce the risk of concurrent diseases because of bone grafting, which is the future trend of bone grafting material. Meanwhile, three-dimensional reconstruction has been used in clinical practice, and can develop programs for scoliosis orthopedic treatment, provide imaging reference to ensure the security of internal fixation and also has played a huge role in improving the comprehensive efficacy of spinal internal fixation system.

Objective: To evaluate the effect of severe rigid kyphotic scoliosis treated with posterior spinal osteotomy Methods: A total of 11 cases(average 11.2 years) of severe rigid kyphotic scoliosis treated with posterior spinal osteotomy from Mar.2005 to Sept. 2006 were retrospective. Of those cases, 3 were of neurofibromatosis, 5 of congenital scoliosis, 1 of poliomyelitis and 2of idiopathic scoliosis. The flexibility of all patients was less than 25%. They had an average follow-up period of 1.3 years (0.5-2 years) Results: There were 3 cases of one segment posterior wedge osteotomy, 2 of two segment posterior wedge osteotomy and 2 of three segment wedge osteotomy. Transpedicular osteotomy was performed in 2 cases, and the last 2 cases encountered vertebral resection and posterior column removed. The average kyphotic angle was 108 degrees (ranging from 87 to 135 degrees) and the average scoliosis angle was 97 degrees (ranging from 65 to 135 degrees) before operation. After operation the average kephotic angle was corrected to 49 degrees (the correction rate was 55%) and the average scoliosis angle was corrected to 37 degrees(the correction rate was 66%) . The height rose up by an average of 4.7 cm. No neurological complication happened in all the 11 cases. Conclusion: It is an effective method that severe rigid kyphotic spinal scoliosis is treated with posterior osteotomy.

Objective To investigate the factors that may contribute to radiculopathy in degenerative lumbar stenosis associated with scoliosis(DLSS) and their relationship with the pattern of the scoliosis. Methods 22 consecutive DLSS patients with radiculopathy with a mean age of 71 years were analyzed retrospectively. The involved symptomatic roots were judged by pain distribution, neurological findings, nerve root infiltration with lidocaine, and confirmed by intraoperative findings and postoperative alleviation of symptoms. The compression factors were determined by myelography (22 cases), discography (3 cases), CT myelography (14 cases), or CT discography (3 cases), MR (6 cases) and radiculography (14 cases). The upper end vertebra, the lower end vertebra, the Cobb's angle, and the lateral displacement of the vertebrae were measured on the plane radiographs. The vertebral displacement was classified into two groups: slip group (more than 10 mm) and nonslip group (less than 10 mm). Results 5 of L3 nerve roots were affected (14%), L4 roots 15 (42%), L5 roots 12 (33%) and S1 roots 4 (11%). Of these, both L3 and L4, and both L5 and S1 were involved in 5 and 4 patients respectively. L3 and L4 were more compressed by foraminal or extra-foraminal stenosis, while L5 and S1 were commonly affected by lateral recess stenosis (?2=10.08, P

Objective To evaluate the prevalence of atherosclerosis in Chinese premenopausal women with systemic lupus erythematosus (SLE) and study possible associations between non-traditional risk factors with premature atherosclerosis. Methods One hundred and eleven premenopausal women with SLE and 40 healthy controls without clinical cardiovascular disease were evaluated. B-mode ultrasonography was used to measure carotid plaque and intima-media wall thickness( IMT). The relationship between the patients' clinical characteristics and carotid plaque was examined. At the same time, B-mode ultrasound was used to measure flow-mediated dilation (FMD) and nitroglycerin-mediated dilation (NMD) in the brachial artery. Using this method, the difference in endothelial function between SLE patients and controls was assessed. T-test,χ2 test and logistic regression were used for statistical analysis. Results Carotid plaque was more frequently observed in patients with SLE (16 of 111 patients) than in control subjects (0 of 40 subjects) (P=0.007). The mean IMT (m-IMT) (0.62 mm vs 0.45 mm, P<0.01) and maximum IMT(M-IMT) (0.7 mm vs 0.6 mm, P<0.01) was significantly higher in patients than in controls. As compared with patients without plaque, patients with plaque were significantly older, had longer disease duration, higher body mass index (BMI), higher blood pressure, shorter prothrombin time, elevated C-reactive protein level, higher SLICC score, higher cumulative prednisone dose, less hydroxychloroquine accumulated dosage, higher m-IMT and M-IMT, lower FMD and NMD. In logistic regression analysis, older age (P=0.012, OR=1.137), higher BMI (P=0.051, OR=1.205) and higher SLICC score (P=0.000, OR=2.888) were independently related to the presence of plaque. Conclusion SLE patients have higher prevalence of carotid atherosclerosis plaque than healthy controls and the age at onset is younger than controls. In addition to traditional risk factors for cardiovascular disease, SLE itself and disease related factors play important roles in premature atherosclerosis in SLE. SLE patients have significant endothelial dysfunction. Thus, endothelial dysfunction can be regarded as one manifestation of premature atherosclerosis in SLE.