BACKGROUND: Cervical intervertebral foramen stenosis induced by cervical spondylosis of nerve root type usual y requires surgical treatment. The ways mainly include anterior cervical discectomy and fusion and cervical posterior intervertebral foramen decompression. Which is the best way is stil inconclusive. With innovation, anterior cervical discectomy and fusion for cervical spondylosis of nerve root type has become the mainstream in the current treatment. OBJECTIVE: To study the relationship between curative effects and intervertebral foramen-associated parameter changes in patients with cervical spondylosis of nerve root type after anterior cervical discectomy and fusion. METHODS: From March 2011 to April 2013, 132 patients with cervical spondylosis of nerve root type were treated with anterior cervical discectomy and fusion in the Changzheng Hospital Affiliated to the Second Military Medical University. Neck pain and arm pain visual analogue score, neck disability index score and imaging changes were evaluated before and after treatment. RESULTS AND CONCLUSION: 132 patients were fol owed up for 25(4-28) months. Significant differences in neck pain visual analogue scale, anterior intervertebral disc height, posterior intervertebral disc height, intervertebral foramen height, anterior and posterior diameters of the intervertebral foramen, the area of the intervertebral foramen, and the Cobb angle of the fused segment were detected in al patients before and after treatment (P < 0.05). Posterior intervertebral disc height was positively correlated with intervertebral foramen area (r=0.427, P=0.000). The increased Cobb angle of the fused segment was negatively associated with the size of intervertebral foramen (r=-0.273, P=0.003). Intervertebral foramen area was negatively associated with arm pain visual analogue score (r=-0.502, P=0.000). These results indicated that anterior cervical discectomy and fusion with an interbody fusion cage can obviously enlarge intervertebral foramen in patients with cervical spondylosis of nerve root type, and obtain good curative effect. The size of the intervertebral foramen is negatively related to the axial pain. The reconstruction of the intervertebral disc height is necessary to expand the intervertebral foramen. However, the increase of the curvature fusion segments is not helping to expand the intervertebral foramen.

BACKGROUND:Intervertebral disc degeneration is one of the ancient and common clinical diseases. Its complex pathogenesis affected by various factors, such as environment and genes, is stil in debate. Because of the technical limitations, there is stil no deep understanding on the molecular mechanism of intervertebral disc degeneration. However, its molecular mechanism in recent years has made considerable development. OBJECTIVE: To summarize and discuss the molecular mechanism of intervertebral disc degeneration, thereby providing the basis for the effective treatment. METHODS: CNKI and Medline databases were retrieved by the first author using computer to search relevant articles published from 2005 to 2015. The key words were “intervertebral disc degeneration, molecular mechanism, environmental factors, genes, matrix, degradation enzyme,inflammatory factor, biological environment, treatment” in Chinese and English, respectively. Mechanisms of intervertebral disc degeneration, involving genes, cel senescence and apoptosis, degradation enzyme and substrate, inflammatory cytokines, were summarized to explore the pathogenesis and possible effective treatment of intervertebral disc degeneration. RESULTS AND CONCLUSION:Totaly 153 articles were initialy retrieved and finaly 52 articles were included in result analysis according to inclusive and exclusive criteria. Unique structure and biochemical properties of the intervertebral disc are easy to cause intervertebral disc degeneration. Traditionaly, environmental factors, such as occupation and smoking, are considered as the main factors inducing intervertebral disc degeneration; however, more and more studies have shown that genes have the most important influence on intervertebral disc degeneration. Declined extracelular matrix, increased degradation enzymes, and overexpression of inflammatory factors can al destroy the entire structure of intervertebral disc, and accelerate the process of intervertebral disc degeneration. Effective treatment for intervertebral disc degeneration can be formulated depending on the deep understanding on its molecular mechanisms. Although there is a further understanding on the molecular medium of intervertebral disc degeneration, the complex biochemical environment within the intervertebral disc is stil a great chalenge to the treatment of intervertebral disc degeneration.

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 compare the biomechanical effects of n-HA/PA66 vertebral body cage and percutaneous vertebroplasty for treating osteoporotic vertebral fracture, so as to provide theoretical foundations for clinically choosing operative approach and numbers of n-HA/PA66 cage. Methods Based on finite element models of normal vertebral T11-L3, four finite element models of vertebral T11-L3 with n-HA/PA66 cage implanted by different approaches (transversus approach A, B and psoas major muscle approach A, B) were established. Two controlled models without intertransverse ligaments were also built. Besides, two finite element models of osteoporotic vertebral T11-L3 with injection of 1.8 mL or 3.6 mL bone cement were built, respectively. The loads of 500 N and force torque of 7 N·m from different directions were applied on nine models, to calculate and analyze the displacement and stress of the osteoporotic vertebrae during standing, extension, anteflexion, lateral bending, and rotation, and to investigate the biomechanical effects from two kinds of osteoporotic vertebral fracture treatment on vertebral body. Results Under the same loading, bone cement could lead to a larger stress increase while a smaller displacement decrease in vertebral body compared with n-HA/PA66 cage. The model with n-HA/PA66 cage implanted by psoas major muscle approach A (namely, a cage was implanted through psoas major muscle) had the minimal increase in vertebral stress while the maximum decrease in displacement. Conclusions In order to reduce the risk of the additional fracture due to stress increment and recover the stiffness of osteoporotic vertebrae, clinicians are suggested to implant one n-HA/PA66 cage through psoas major to treat the osteoporotic vertebral fractures.

Objective To explore the biomechanical effect from different volumes of bone cement on osteoporotic spine T11-L3 at different levels of osteoporosis in vertebroplasty by the finite element method, so as to offer theoretical foundation for the selection of cement volume before vertebroplasty. Methods Based on CT scan images, the finite element models of spine T11-L3 were built and validated. Twelve models of osteoporotic spine T11-L3 without bone cement were developed as the control models. The spine L1 was injected with 1.8 mL and 3.6 mL bone cement, respectively, to strengthen the spine and build 24 models of spine T11-L3 at different levels of osteoporosis. The vertical load (500 N) and the torque (7 N·m) were applied on superior face of the spine T11 to calculate and analyze vertebral stress and displacement under the working conditions of standing, backward extension, anteflexion, lateral bending and rotation, respectively. Results After injection of bone cement, the changes in vertebral stress and displacement under torsional loads were the maximum. For the models with injection of 1.8 mL bone cement, as the levels of osteoporosis increased, the stress of spine L1 increased from 55.0% to 87.7%, and the displacement decreased from 6.5% to 32.0% under torsional loads. The torsional stress of spine T12 and L1 at the highest level of osteoporosis increased by 3.6% and 5.7%, respectively. For the models with injection of 1.8 mL bone cement, as the level of osteoporosis increased, the stress of spine L1 increased from 288.5% to 313.8%, and the displacement decreased from 8.9% to 44.7% under torsional loads. The torsional stress of spine T12 and L1 at the highest level of osteoporosis increased by 7.3% and 7.6%, respectively. Conclusions The deterioration in osteoporosis and the increase in cement volume will lead to the increase in vertebral stress. The vertebral stress and displacement will increase most under torsional loads. Therefore, for patients with vertebral fracture at high level of osteoporosis, low-dosage bone cement should be considered in order to avoid a large increase in stress, and torsional movement of the patients should be restricted.

Objective: To analyze the quality of final exam papers of Surgery and Field Surgery for five-year medical students from comprehensive class of Grade 2014, so as to check the mastery of different students, perfect the construction of item banking, verify the quality of teaching and learning, and thus provide references to further teaching reform. Methods: SPSS 21.0 was used for statistical analysis of 133 Surgery and Field Surgery papers of students from comprehensive class of Grade 2014. Results: The highest score was 93.5, the lowest score was 52.0, and the average score was (70.60±9.00). Among those 133 students, six students were failed, occupying 4.51%. The overall difficulty coefficient of examination paper (P) was 0.71, and P value of multiple choice questions and blank-filling questions was 0.4-0.7. Difference degrees (D) of question types were more than 0.600 and the overall reliability was 0.764. Scores of examination paper were generally in normal distribution. The average scores of students form anesthesiology major were higher than those of students from navigation medicine major, but the average scores of students from above two majors were higher than those of students from psychology major, with statistically significant differences (P<0.05). Conclusion Question types of this paper are comprehensive and reasonable. The overall difficulty is not high, the difference degree is good, the reliability is good and the score distribution is reasonable. However, the question should be further improved, focusing on the reasonable distribution of difficulty of question. In addition, we should strengthen the teaching of the course in students from psychology major.