Occipitocervical anatomy is characterized by deep location, complex structure, and unique function. The motor function of the occipitocervical region is highly flexible. How to achieve satisfactory spinal cord decompression with minimal invasion and how to effectively reconstruct biomechanical stability and maintain flexible motor function are important clinical problems that need to be solved urgently. However, this has also led surgeons to focus too much only on surgical techniques rather than comprehensive understanding and treatment of the disease. There are three common but easily ignored issues in clinical practice: Firstly, the importance of occipitocervical anatomy research to improve clinical diagnosis and treatment. The stability of the base of the skull and the lower cervical vertebra should also be considered in clinical diagnosis and treatment. Secondly, atlanto-occipito-atlantoaxial joint and local ossification of the posterior longitudinal ligament. Atlantoaxial flexibility may lead to the earliest appearance of partial ossification of the posterior longitudinal ligament in this region. Thirdly, atlanto-occipito-atlantoaxial joint osteoarthritis is often neglected, and paying attention to the diagnosis and treatment of atlanto-occipito-axial joint osteoarthritis will improve the overall curative effect of occipito-cervical diseases.

Cervical hyperextension injury is a common special type of cervical spinal cord injury. While several problems should be further understood in clinical practice. Why do some seemly slight hyperextension forces cause such severe cervical spinal cord injury? Why do the cervical spinal cord hyperextension injuries show various and different manifestations? Why does the intrinsic muscle function of the hand of patients with hyperextension cervical spinal cord injury recover slowly or even fail to recover? How can we tell the differences between injury mechanisms of hyperextension and whiplash injury of cervical spine? Why is the surgical intervention always necessary to be performed for cervical hyperextension injury? The author discusses the above problems encountered by clinicians to strengthen the understanding of the disease, and hopes to provide some information for the clinical diagnosis and treatment.

Objective To investigate the imaging characteristics and pathogenic manifestations of thoracic ossification of the ligamentum flavum complicated with dural ossification.Methods CT and MRI imaging data of 62 segments from 29 patients with thoracic ossification of the ligamentum flavum (TOLF) treated with "en bloc resection of lamina and ossified mass" were retrospectively analyzed.There were 19 males and 10 females,aged 54.9±10.25 years (36-77 years),16 segments in 11 cases with dural ossification (DO) and 46 segments in 18 cases without DO.The ossified mass shape,the relationship between ossified mas and dura mater on cross section of CT bone window and MRI T2WI,and the ossified mass occupational rate (OR) of the spinal canal were investigated.Pathologic features of TOLF-DO from 2 patients were analyzed by H&E staining.Results The shape of ossified mass was as followed,in 16 segments with DO,7 segments (43.8％) by CT and 2 segments (12.5％) by MRI showing ossification layer on the dural sac side of ligamentum flavum;1 segment (6.3％) by CT and 2 segments (12.5％) by MRI showing typical Tram track sign.The relationship between ossified mass and dura mater was that 7 segments (43.8％) by CT and 7 segments (43.8％) by MRI with "C" sign and 7 segments (43.8％) by CT and 8 segments (50.0％) by MRI with "V" sign.The ossified mass OR was 60.5％± 13.0％ in the group with DO and 42.2％± 12.3％ in the group without DO.There was a significant difference between the two groups (t=5.192,P＜0.001).Among the 16 segments with DO,the ossified mass OR of 7 segments with "C" sign was 68.8％± 12.8％ and that of the other 9 segments without "C" sign was 54.39％±9.9％.There was significant difference between the two groups (t=2.45,P=-0.028).Histological examination showed that there were two pathological phenomena in the dura tissue adjacent to ossified mass.The one,there were fibrocartilage,cartilage and osteogenesis in the dura mater.The other,the unossified dura mater fused with the ossified mass but with clear histological demarcation,while the dura mater on the ventral side of the ossified ligamentum flavum atrophies or disappeared.Conclusion The occurrence of dural sac ossification is associated with the ossification of ligamentum flavum beginning at the side of the dural sac and the persistent thickening of the ossified mass.The pathological manifestations of DO are ossification of dural tissue or fusion of dural with ligamentum flavum ossification.

Objective To investigate the clinical effect of anterior controllable antedisplacement and fusion (ACAF) for the treatment of ossification of the posterior longitudinal ligament (OPLL) of the cervical spine.Methods The data of 45 cases with cervical posterior longitudinal ligament ossification treated by ACAF from March 2017 to October 2017 were retrospectively analyzed,including 25 males and 20 females,age 45-68 years,average 57.5 years.There were 18 cases involving C3 vertebral body,30 cases involving C4 vertebral body,40 cases involving C5 vertebral body,34 cases involving C6 vertebral body,and 7 cases involving C7 vertebral body.The function of the neural function was evaluated by the Japanese Orthopaedic Association (JOA) scoring system at preoperation and latest follow-up.The curvature of the cervical spine was measured on the lateral X-ray film of the cervical spine,the maximum occupying ratio of the spinal canal was measured on the cross section of the CT scan,and compression of the cervical spinal cord was evaluated by the cervical MRI.Results Patients were followed up for 3 to 6 months (average,3.9 months).The improvement of neurological function was obtained in all the patients.The JOA score improvement rate at the latest follow-up was 71.3％±9.6％.The cervical lordosis was improved from preoperative 4.5°±3.8° to 10.3°±4.8° at the latest follow-up.The canal stenosis ratio was decreased from preoperative 54.3％±8.2％ to 12.5％±5.3％ at the latest follow-up.MRI showed that the cervical spinal cord was adequately decompressed in situ.No specific complications were identified that were associated with this technique.Conclusion The present study elaborates the surgical tips and demonstrates the satisfactory outcome of ACAF for the treatment of OPLL.This novel technique has the potential to serve as an alternative surgical technique for the treatment of cervical OPLL.

Objective To evaluate theclinical efficacy and safety of anterior cervical ossified posterior longitudinal ligament en bloc resection (ACOE),and analyze the advantages of ACOE compared to the traditionally anterior cervical surgery.Methods The clinical datawith more than one year follow-up of 96 patients suffered from cervical ossification of the posterior longitudinal ligament(OPLL) from April 2010 to March 2017 was retrospectively analyzed,including 57 males and 39 females,aged 32-69 years,average 54.6±8.7 years.There were 29 cases of nodular type (30.2％),48 cases of segmental type (50.0％),5 cases of continuous type(5.2％),and 14 cases of mixed type (14.6％).The neurological function assessments before and after operation were performed using the Japanese Orthopaedic Association (JOA) scoring system and the visual analogue scale (VAS) scoring system.The effect of ossified mass resection was observed by three-dimensional reconstruction CT scan.The spinal cord decompression was evaluated by MRI.The cervical curvature was compared before and after surgery by cervical lateral radiograph.The operation time,intraoperative blood loss,recovery rates of the JOA scores and complication rates of this group were compared with the cases of anterior cervical ossified posterior longitudinal ligament piecemeal resection (ACOP) reported by the recent literature to analyze the clinical efficacy,safety and advantages of ACOE.Results All the surgeries of 96 cases were successfully performed,including 57 cases (59.4％) with subtotal resectionof single vertebra,31 cases (32.3％) with subtotal resectionof doublevertebras,1 case (1.0％) with expanded intervertebral decompression,4 cases (4.2％) with "vertebra + semi-vertebra" subtotal resection,1 case (1.0％) with "semi-vertebra + vertebra + semi-vertebra" subtotal resection,2 cases with "double vertebras + semi-vertebra" subtotal resection (2.1％).Ninty-six cases were followed up for 12 to 78 months,with an average of 28.0±9.3 months.The preoperative JOA score with (11.38±2.80) scores was increased to 15.32± 1.62 scores at the last follow-up,and the recovery rate of JOA score was 74.63％±13.18％.The preoperative VAS score with 6.00±1.41 scores was reduced to 2.35±1.11 scores at the last follow-up.The cervical curvature increased from 10.4°±9.0° before surgery to 15.8°±8.1° at the last follow-up.CT showed that the ossified masses of the surgical segments were completely excised without residue;MRI showed that the compressionsof spinal cords and dural sacs were completely relieved,with nice morphology recovery.There was no neurological deterioration in this group.There were 6cases of cerebrospinal fluid leakage (CSFL),3 cases of C5 nerve palsy,1 case of Hornersyndrome,2 cases of dysphagia and hoarseness,1 case of titanium mesh subsidence with screw loosing.At the final followups,except one case of occasional throat foreign body sensation,the above complications were all remittedat different followup periods.Compared with the cases of ACOP reported by the recent meta-analysis,the operation time,the intraoperative blood loss,the complication rate of dysphagia with hoarseness and neurological deterioration were lower than those reported in the literature.The recovery rate of JOA scorewas higher than which reported in the literature.Conclusion ACOE is safe and effective for the treatment of cervical OPLL,which may be superior to traditional anterior cervical surgery in terms of surgical safe-ty,controllability of cerebrospinal fluid leakage and improvement of neurological function.

BACKGROUND: Autologous platelet-rich plasma (PRP) is a concentrate of platelet-rich plasma protein derived from autologous whole blood. The activated platelets can release a large number of high concentrations of growth factors and bioactive substances, which provides a theoretical basis for its application in various disciplines and fields. At the same time, autologous PRP has been popularized because it will not cause immune rejection with extensive sources, easy to extract and low cost.OBJECTIVE: To summarize the preparation method and performance of autologous PRP, and to explore its latest research results and underlying mechanisms in spinal surgeries.METHODS: A computer-based online retrieval of CNKI and PubMed databases was performed for articles concerning autologous PRP used in spinal surgeries. Finally, 42 eligible literatures were included according to the inclusion and exclusion criteria.RESULTS AND CONCLUSION: (1) Autologous PRP is rich in a variety of growth factors and bioactive substances, so it has been used in the fields of disc repair, bone conduction and osteoinduction, and its effectiveness has been confirmed through abundant basic and clinical trials. (2) Meanwhile, autologous PRP also is used for tissue repair and skin regeneration, such as spontaneous cerebrospinal fluid leakage and pressure ulcer. (3) Notably, autologous PRP has shown a promising prospect in the field of spinal surgeries.

Objective To investigate the pathogen distribution and risk factors of pulmonary infection after acute cervical spinal cord injury (ACSCI) in an attempt to offer reference for early antiinfection therapy.Methods The study comprised 223 cases who were admitted from October 2011 to October 2014.There were 149 males and 74 females,at (43.3 ± 13.5) years of age.Species of pathogens identified were gram-positive,gram-negative and mixed.Effects of age,gender,injury types and tracheotomy on pathogen distribution were analyzed.Results Gram-negative infection was found in 114 cases (51.1％),with tracheotomy accounting for 7.0％ of the cases and death accounting for 1.8％ of the cases,and the main causative pathogens were Klebsiella pneumonia,Escherichia coli,Pseudomonas aeruginosa and Acinetobacter baumannii.Gram-positive infection was found in 41 cases (18.4％),with tracheotomy accounting for 12.2％ of the cases and death accounting for 7.3％ of the cases,and the main causative pathogens were Staphylococcus aureus and Streptococcus pneumonia.Mixed infection was found in 68 cases (30.5％),with tracheotomy accounting for 22.1％ of the cases and death accounting for 13.2％ of the cases.Gender had no significant correlation with pathogen distribution.For the cases of complete spinal cord injury and tracheotomy,the ratio of mixed infection increased significantly (P ＜ 0.05).For the cases younger than 30 years,the pathogens were mainly gram-positive bacteria (P ＜ 0.05).Conclusions Main pathogens of pulmonary infection after ACSCI are gram-negative bacteria.The cases younger than 30 years are associated with higher risk of grampositive infection,while the cases with complete injury or tracheotomy are associated with higher risk of mixed infection.

BACKGROUND:Current studies on the pathogenesis of ossification of the ligamentum flavum are stil in a preliminary stage, and any single factor influencing incidence of ossification of ligamentum flavum cannot completely explain the pathogenesis of this disease. OBJECTIVE:To summarize the pathogenesis of ossification of ligamentum flavum. METHODS:A computer-based online search was conducted in PubMed, Wanfang, and CNKI databases from January 1990 to December 2015 to screen the relevant literatures regarding the pathogenesis of ossification of the ligamentum flavum using Chinese and English key words“ossification of ligamentum flavum, basic research, pathogenesis, gene, bone morphogenetic protein, osteopontin”. Consequently, 63 eligible literatures were included after the exclusion of the repetitive and old ones. RESULTS AND CONCLUSION:Current studies have shown that ossification of the ligamentum flavum is a disease that results from multiple genetic and environmental causes and is one of the main causes of spinal stenosis. Tissue degeneration, local biomechanics, genetic factors, metabolic disorders, trace elements and vascular inflammation are all shown to be involved in the pathogenesis of ossification of ligamentum flavum.

BACKGROUND:Spinal cord ischemia-reperfusion injury is a serious secondary injury of the spinal cord. Multifactor could contribute to the mechanism of this injury, and many therapeutic measures emerge, but the therapeutic effect is not ideal.
OBJECTIVE:To investigate the protective effects and mechanism of hydrogen-rich saline on spinal cord ischemia-reperfusion injury in rabbits.
METHODS:ZIVIN method was adopted to prepare the model of spinal cord ischemia-reperfusion injury. The rabbit models were randomly divided into model group, sham operation group, and hydrogen-rich saline group.
RESULTS AND CONCLUSION:Improved Tarlov scores for the evaluation of motor function were significantly increased in hydrogen-rich saline group compared with the model group at 6, 12, 24, 72 hours after reperfusion (P<0.01). The contents of malondialdehyde were significantly lower (P<0.05), while catalase activity was significantly higher (P<0.05) in hydrogen-rich saline group than that in model group at 72 hours after reperfusion. Hematoxylin-eosin staining revealed that, spinal cord anterior-horn motor neurons maintained intact structure in sham operation group;more necrotic spinal cord anterior-horn motor neurons were found in model group, and granular-vacuolar degeneration occurred in the endochylema. In hydrogen-rich saline group, the structure of spinal cord anterior-horn motor neurons was basical y intact, only a smal amount of spinal cord anterior-horn motor neurons appeared vacuolar degeneration. TUNEL staining showed no apoptotic spinal cord anterior-horn motor neurons in sham operation group. Many inflammatory cel s and apoptotic neurons were found in model group. There were few inflammatory cel s and apoptotic neurons in hydrogen-rich saline group. Hydrogen-rich saline can prevent the apoptosis of spinal cord anterior-horn motor neurons in rabbits with spinal cord ischemia-reperfusion injury, and the underlying mechanism is associated with antioxidative effect.

BACKGROUND:Exogenous basic fibroblast growth factor (bFGF) plays an important role in the ligament tissue healing process, and the use of transgenic methods to transfect exogenous genes into cells can promote the secretion of bFGF. OBJECTIVE:To observe phenotypic changes and the bFGF protein expression after bFGF recombinant adenovirus was used to transfect rabbit bone marrow mesenchymal stem cells (BMSCs). METHODS:Passage 2 BMSCs were divided into three groups:Ad.bFGF-eGFP group, Ad.eGFP group and control group. Under a phase contrast microscope we observed the changes in cellmorphology. The expression of bFGF protein in BMSCs was determined by enzyme-linked immunosorbent assay (ELISA). The proliferative curve was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). RESULTS AND CONCLUSION:The transfected cells showed a uniform phenotype of fibroblasts. MTT colorimetric assay revealed that more proliferative activity of transfected BMSCs was shown in the Ad.bFGF-eGFP group than in the Ad.eGFP group and control group. ELISA results showed that expression of bFGF protein was higher in the Ad.bFGF-eGFP group than in the Ad.eGFP group and control group (P<0.05). BFGF recombinant adenovirus can induce the differentiation of BMSCs into fibroblasts, increase proliferative ability and promote the expression of bFGF protein.