Lyophilized bovine acellular tendon linear fiber material for the reconstruction of attachment structure of paraspinous muscles: an animal in vivo study.

Low back pain is common after lumbar spine surgery and the injury from extensive detachment of paraspinal muscles during the surgery may play a vital role. Previously, we prepared a bovine acellular tendon fiber (ATF) material through lyophilization and proved that it could retain its original fibrillar structure and mechanical properties. The objective of this study is to evaluate the effectiveness of this new fiber material used for attachment structure reconstruction of paraspinal muscle. Defect of spinous process, interspinous and supraspinous ligament was established on lumbar spine in rabbit and rat and ATF linear material was implanted to reconstruct the attachment structure. Ultrasound showed the cross-sectional area of the paraspinal muscle in ATF group was larger than that of control group in rats. MRI showed the irregular shape and high signal changes in control group, but regular shape and uniform signal in the ATF group in rabbit. For Electromyogram, the frequency of evoked potential in control group was lower than ATF group and normal rats. HE and Masson staining showed good tissue healing, and immunohistochemical results showed the immune rejection of ATF is significantly lower than that of suture. Reconstruction of the attachment structure of paraspinous muscles with ATF linear material could maintain the morphology, volume and function of paraspinal muscle. ATF material has the potential to be used to manufacture personalized ligaments and other tissue engineering scaffolds. Graphical abstract.

Aponeurosis discission, a low-detergent method for tissue-engineered acellular ligament scaffolds.

Detergent treatment is the most commonly used method for the decellularization of ligaments and tendon grafts. However, it is well recognized that detergent treatment can also adversely affect the extracellular matrix. This study found that discission into the aponeurosis layer of the patellar tendon (PT) before decellularization is conducive to extracting cells from the PT using a low quantity of detergent in a short time period. The acellular aponeurosis discission ligament (AADL) retains its native collagen fibril structure and mechanical properties. Moreover, the PT retained cell and tissue compatibility in vitro and in vivo. After implantation into a defective allogeneic PT, we found that the AADL healed well in the host, and its collagen structure exhibited gradual improvement 12 months after implantation with satisfactory reconstruction. IMPACT: The aponeurosis of tendons/ligaments is the main barrier to achieving complete decellularization, and it thus prevents complete recellularization for applications in tissue engineering. Aponeurosis can obstruct the removal of cell components. We found that excising the aponeurosis before decellularization allows for the removal of cellular components with a reduced amount of detergent, thus improving the biological properties of the acellular ligament. To the best of our knowledge, no similar studies have been performed. Graphical abstract.

Consensus statement on diagnosis and treatment of cervical ossification of posterior longitudinal ligament from Asia Pacific Spine Society (APSS) 2020.

PURPOSE: The study aimed to develop an evidence-based expert consensus statement on diagnosis and treatment of cervical ossification posterior longitudinal ligament (OPLL). METHOD: Delphi method was used to perform such survey, and the panel members from Asia Pacific Spine Society (APSS) 2020 were invited to answer the open-ended questions in rounds 1 and 2. Then the results were summarized and developed into a Likert-style questionnaire for voting in round 3, and the level of agreement was defined as 80%. In the whole process, we conducted a systematic literature search on evidence for each statement. RESULTS: Cervical OPLL can cause various degrees of neurological symptoms, an it's thought to be more common in Asia population. CT reconstruction is an important imaging examination to assist diagnosis and guide surgical choice. Segmental, continuous, mixed, and focal type is the most widely used classification system. The non-surgical treatment is recommended for patients with no or mild clinical symptoms, or irreversible neurological damage, or failed surgical decompression, or condition cannot tolerant surgery, or refusing surgery. As OPLL may continue to develop gradually, surgical treatment would be considered in their course inevitably. The surgical choice should depend on various conditions, such as involved levels, thickness, and type of OPLL, skill-experiences of surgeons, which are listed and discussed in the article. CONCLUSION: In this statement, we describe the clinical features, classifications, and diagnostic criteria of cervical OPLL, and review various surgical methods (such as their indications, complications), and provide a guideline on their choice strategy.

A novel revision surgery for treatment of cervical ossification of the posterior longitudinal ligament after initial posterior surgery: preliminary clinical investigation of anterior controllable antidisplacement and fusion.

BACKGROUND: Cervical ossification of the posterior longitudinal ligament (OPLL) is a progressive disease. Posterior decompression surgery is reported to be an effective and comparatively safe procedure with few complications for treatment of patients with myelopathy caused by OPLL. However, some patients require revision surgery because of late neurological deterioration due to OPLL progression or kyphotic changes in cervical alignment. This study reports preliminary clinical results of anterior controllable antidisplacement and fusion (ACAF), a novel revision surgery after initial posterior surgery for OPLL. METHODS: From January 2017 to June 2018, ten patients with cervical OPLL who underwent ACAF revision surgery after initial posterior surgery were included in this study. The mean age was 62.1 ± 8.0 years (52-78), and the mean interval between initial posterior surgery and revision was 78.0 ± 48.2 months (5-180). The Japanese Orthopaedic Association (JOA) scales, Neck Disability Index (NDI), visual analog scale (VAS), and surgical complications were recorded. RESULTS: The mean surgery time was 179.3 ± 41.8 min (120-240), and the mean blood loss was 432.5 ± 198.3 ml (225-850). The patients were followed up for at least 12 months. The JOA scores improved from 8.7 ± 2.8 to 13.4 ± 2.4; the mean improvement rate was 59.9% ± 16.1%. Postoperative NDI and VAS scores were 13.3 ± 3.7 and 2.0 ± 1.6, respectively, and were significantly improved compared to those before the procedure (P < 0.05). Cervical lordosis improved from 3.8 ± 4.3° to 17 ± 4.6° after revision surgery. There was only one instance of cerebrospinal fluid (CSF) leakage; no instances of postoperative hematoma, C5 root palsy, or hoarseness occurred. CONCLUSIONS: The present study demonstrates that excellent postoperative outcomes can be achieved with the ACAF technique for revision treatment of OPLL. Though further study is required to confirm the conclusion, this novel technique has the potential to serve as an alternative surgical technique for revision treatment of OPLL.

Evaluation of Measuring Methods of Spinal Canal Occupation Rate in Thoracic Ossification of Ligamentum Flavum.

OBJECTIVE: The degree of hypertrophy of thoracic ossification of ligamentum flavum (TOLF) is related to the severity of the myelopathy. There is no uniform measuring method to calculate the spinal canal occupation ratio (COR) of TOLF simply and effectively. The study was to determine an appropriate measuring method to calculate the COR of TOLF. METHODS: A total of 37 computed tomography cross-sectional imaging scans (bone window) from 22 patients were analyzed retrospectively in this study. The ventral side of the lamina or superior facet was selected as bottom in Method 1, and a line perpendicular to the anteroposterior diameter and on the dorsal side of the spinal canal was selected as bottom in Method 2. The maximum thickness of the bilateral ossified mass to the bottom is d1 and d2. The maximum distance from the anterior wall of the spinal canal to the bottom is d. COR of Method 1 or 2 was (d1 + d2)/2d × 100%. Standard COR values calculated by software served as controls. RESULTS: The standard COR values were <50% in 10 images, 51%-60% in 9 images, 61%-70% in 10 images, and >71% in 8 images. There was no significant difference between COR1 and COR in every range. There were significant differences between COR2 and COR in the ≤50%, 51%-60%, and 61%-70% groups but they were not statistically significant in the >70% group. CONCLUSIONS: Method 1 is a convenient and practical method to measure the COR of ossification in patients with TOLF.

Imaging grading system for the diagnosis of dural ossification based on 102 segments of TOLF CT bone-window data.

Thoracic ossification of the ligamentum flavum (TOLF) complicated with dural ossification (DO) is a severe clinical disease. The diagnosis of DO preoperatively remains challenging. The current study retrospectively analyzed imaging features of 102 segments with TOLF from 39 patients and proposed a grading system for evaluating DO risk. Logistic regression results showed that unilateral spinal canal occupational rate (UCOR), tram track signs, and C-signs were all risk factors for DO (odds ratios of 5.393, 19.734 and 72.594, respectively). In validation analyses for the TOLF-DO grading system, sensitivity was 76.0% (19/25), specificity was 91.0% (70/77), and Youden's index was 0.66. Thus, implementation of the TOLF-DO grading system has the potential to improve the diagnosis of DO.

Rapid prototyping technology and its application in bone tissue engineering.

Bone defects arising from a variety of reasons cannot be treated effectively without bone tissue reconstruction. Autografts and allografts have been used in clinical application for some time, but they have disadvantages. With the inherent drawback in the precision and reproducibility of conventional scaffold fabrication techniques, the results of bone surgery may not be ideal. This is despite the introduction of bone tissue engineering which provides a powerful approach for bone repair. Rapid prototyping technologies have emerged as an alternative and have been widely used in bone tissue engineering, enhancing bone tissue regeneration in terms of mechanical strength, pore geometry, and bioactive factors, and overcoming some of the disadvantages of conventional technologies. This review focuses on the basic principles and characteristics of various fabrication technologies, such as stereolithography, selective laser sintering, and fused deposition modeling, and reviews the application of rapid prototyping techniques to scaffolds for bone tissue engineering. In the near future, the use of scaffolds for bone tissue engineering prepared by rapid prototyping technology might be an effective therapeutic strategy for bone defects.

Fibroblast growth factor 2 induces mesenchymal stem cells to differentiate into tenocytes through the MAPK pathway.

Mesenchymal stem cells (MSCs) differentiate into numerous different cell types and thus have therapeutic potential for tissue engineering, anti­inflammatory and immunomodulatory purposes. FGF2 may affect the biological behavior of MSCs. MSCs were transduced with either adenovirus­null vector/green fluorescent protein (GFP) or a vector encoding for the overexpression of FGF2/GFP. The expression of FGF2 was demonstrated to be significantly higher in MSC (FGF2) compared with MSC (vector) by qPCR and western blot analysis. In order to investigate the function of FGF2 in MSCs over time, it was observed that FGF2 stimulates cell proliferation and induces cell differentiation by activating the mitogen­activated protein kinase (MAPK) signaling pathway. Following blockade of the FGF2­induced activation of the extracellular signal­regulated kinase pathway by overexpression of sprouty isoforms, the marker of differentiation markedly decreased. Altogether, the results demonstrated a novel cell biological mechanism that FGF2 differentiates into tenocytes and the MAPK pathway is key in differentiation.

A universal pedicle screw and V-rod system for lumbar isthmic spondylolysis: a retrospective analysis of 21 cases.

OBJECTIVE: To investigate the surgical outcome of a universal pedicle screw-V rod system and isthmic bone grafting for isthmic spondylolysis. METHODS: Twenty-four patients with isthmic spondylolysis at L5 and grade 0-I spondylolisthesis (Meyerding classification) received isthmic bone graft and stabilization using the universal pedicle screw-V rod system. Back pain was evaluated using the visual analog scale (VAS) and time to bone healing, improvement in spondylolisthesis and intervertebral space height at L5/S1 and L4/L5 were assessed. RESULTS: Twenty-one patients were followed up for 24 months and included in the analysis. Back pain was markedly improved at 3 months postoperatively with a statistical difference in VAS scores compared with preoperative VAS scores (P<0.001). The VAS scores were 0 to 3 at 6 months postoperatively in all patients and no back pain was reported in all patients except 2 patients who complained of back pain after prolonged sitting. X-ray examination showed a bone graft healing time of 3 to 12 months. Grade I spondylolisthesis improved to grade 0 in 4 patients and no noticeable change was observed in the remaining 17 cases. The intervertebral space height at L5/S1 was statistically increased (P<0.05) while no statistically significant change was seen at L4/L5. There was no statistically significant difference in the ROM of the intervertebral disks of L5/S1 and L4/5 before and after surgery. CONCLUSIONS: The universal pedicle screw-V rod system and isthmic bone grafting directly repairs isthmic spondylolysis and reduces back pain, prevents anterior displacement of the diseased segment and maintains intervertebral space height, thus offering a promising alternative to current approaches for isthmic spondylolysis.

[Clinical observation and evaluation of reasons for pseudarthrosis after anterior cervical fusion].

OBJECTIVE: To explore the causes of pseudarthrosis and evaluate the clinical neurological function and neck subaxial symptoms after anterior cervical fusion. METHODS: A total of 412 patients were followed up with an average of 5.4 years. The bone mineral density, bone graft trimming and placement, management of endplate, smoking and neck support fixation time were observed. Japanese Orthopedic Association (JOA) score was used to evaluate the changes of neurological functions and clinical outcomes. Visual analog scale (VAS) score was used to evaluate the neck subaxial symptoms. And pseudarthrosis was examined by flexion-extension radiography. SPSS statistical software 13.0 was used to evaluate the differences of JOA and VAS scores between pseudarthrosis and control groups. RESULTS: Among them, 37 cases of pseudarthrosis were observed. There were osteoporosis (n = 30 vs n = 119), cartilage end-plate punctuate hemorrhage (n = 18 vs n = 340), 25 and 43 cases with ineffective cervical external fixation (n = 25 vs n = 43) and smoking (n = 26 vs n = 87) in pseudarthrosis and fusion groups respectively. Significant differences existed in the above-mentioned indices between two groups. However, no significant difference existed in bone graft shape between two groups. There were significant differences in JOA and VAS scores between two groups. CONCLUSION: The causes of pseudarthrosis included decreased bone density, osteoporosis, over-curette of endplate, shortness of neck support fixation time and smoking. And pseudarthrosis may influence the long-term recovery of neurological functions or it is correlated significantly with neck symptoms.

Identification of risk factors for respiratory complications in upper cervical spinal injured patients with neurological impairment.

OBJECTIVE: Clinical features of respiratory complications in patients with upper cervical spine injuries (CSI) are unique due to the complex regional anatomy in the region. The objective of this study was to identify the risk factors for respiratory complications in the patients with upper CSI and cervical spinal cord injuries (C-SCI). METHODS: Ninety-two patients (out of 1593 spine injured patients) who met the inclusion criteria of upper CSI were admitted to our hospital from 1992 to 2010. Their records were retrospectively reviewed. RESULTS: Respiratory complications occurred in 16 patients (17.4%). In addition, ventilator-associated pneumonia played an important role in the respiratory complications, however, no pulmonary thromboembolism was found. Death rate in respiratory complication group (RCG, 31.3%) was significantly higher than that in non-respiratory complication group (NCG, 1.3%). In RCG, severe C-SCI (American Spinal Cord Injury Association Grades A and B, OR=34.401; 95% CI, 2.609-5.525) and hypoalbuminemia (OR=24.616; 95% CI, 1.492-6.182) were identified by logistic regression analysis as main risk factors for respiratory complications; whereas levels of neurological injury, quadriplegia, atlanto-axial fractures, smoking history, and electrolyte disturbances were not identified as risk factors (although statistically relevant to respiratory complications). CONCLUSION: Severe C-SCI and hypoalbuminemia played important roles in predicting respiratory complications among the patients with upper CSI and neurological impairment. In addition, levels of neurological injury, quadriplegia, atlanto-axial fractures, smoking history, and electrolyte disturbances are also valuable indicators for these complications. Moreover, prevention of ventilator-associated pneumonia was crucial in the treatment of these patients. However, a screening for deep venous thrombosis was seemingly unnecessary in our patients.

[Short-term clinical results of interspinous dynamic fixation of Coflex for the prevention of adjacent segment degeneration after lumbar fusion].

OBJECTIVE: To observe the short-term clinical results of the adjacent segment degeneration after the implantation of Coflex system at the interspinous space of adjacent segment to lumbar fusion. METHODS: Fifty patients with grade III disc (Thompson MRI classification) of adjacent segment to lumbar fusion were included and divided alternately into two groups according to the order of hospitalization from January to November 2009. Coflex system was implanted at the interspinous space of adjacent segment to lumbar fusion in 25 patients as Coflex group, the other 25 patients did not have any surgical treatment were as control group. The followed up time was 2 years. Visual analogue scale (VAS) score of low back pain, changes of disc height and motion range of adjacent segment to lumbar fusion on X-ray imaging were evaluated by independent sample t-test or paired samples t-test. RESULTS: There were 22 patients in Coflex group and 21 patients in control group were followed up 2 years post-operation. The difference of VAS score between two groups was no significance (P > 0.05). In Coflex group, the change of postoperative disc height was no significance (P > 0.05), but the motion range was significantly reduced to 47% of the preoperative value (t = 7.99, P < 0.05). In control group, the postoperative disc height decreased slightly, without significant difference to the preoperative value (P > 0.05). Between the two groups, no differences of the disc height and motion range were found before operation, but the differences of the disc height changes (t = 6.7, P < 0.05) and motion rang (t = -14.5, P < 0.05) were significant in 2 years post-operation. No complications such as Coflex system loosen, immigration and spinal process fracture were occurred. CONCLUSIONS: Coflex system can obviously limit the motion range and maintain the disc space height of adjacent segment to lumbar fusion, and prevent its degeneration in some degree.

En bloc resection of lamina and ossified ligamentum flavum in the treatment of thoracic ossification of the ligamentum flavum.

OBJECTIVE: We performed a retrospective patient chart review to determine the feasibility and safety of en bloc resection of lamina and ossified ligamentum flavum in the treatment of thoracic ossification of ligamentum flavum (OLF). METHODS: From January 2000 to June 2006, 36 patients with thoracic OLF underwent en bloc resection of lamina and ossified ligamentum flavum by a burr-grinding technique. The range of resection included one lamina superior and one lamina inferior to the diseased segments. Ossified dura mater was removed if present, and simultaneous repair was carried out. RESULTS: The mean preoperative Japanese Orthopedic Association (JOA) score (an evaluation system for thoracic myelopathy with a total score of 11 points) was 5 points (range, 3-9 points). The mean JOA score at the last follow-up visit (mean follow-up period, 3.9 years) was 8.44 points (range, 6-11 points). The range of improvement was from 2 to 6 points, and the mean improvement rate was 60.5% (range, 33.3%-100%). No postoperative aggravation of neurological dysfunction, leakage of cerebrospinal fluid (CSF), wound infection, kyphosis, or recurrence occurred. A CSF cyst found in one patient 3 weeks postoperatively was absorbed automatically after 10 months. CONCLUSION: The en bloc resection technique described here is both safe and effective.

The genetic association of vitamin D receptor polymorphisms and cervical spondylotic myelopathy in Chinese subjects.

BACKGROUND: The association of vitamin D receptor (VDR) gene polymorphisms to the lumbar degenerative disc disease has been previously studied; however, the role of VDR gene polymorphisms in cervical spondylosis remains unknown. METHODS: One hundred fifty four patients with cervical spondylotic myelopathy (CSM) and 156 controls were enrolled. The clinical characteristics were collected and the severity of cervical spondylotic myelopathy was evaluated by magnetic resonance imaging (MRI). The VDR polymorphism genotyping was performed. RESULTS: No significant difference in clinical characteristics was noted between the case and controls. For ApaI polymorphism, the cases had a marked higher prevalence of AA genotype (19.5% vs. 8.3%, P=0.003) and A allele frequencies (34.4% vs. 22.4%, P<0.001) than controls. For TaqI polymorphism, the cases had a significant higher prevalence of TT genotype (67.5 vs. 44.2%, P<0.001) and T allele frequencies (76.9% vs. 54.2%, P<0.001) than controls. The odds ratio for CSM was 2.88 for the ApaI A allele carriers and 4.67 for the TaqI T allele carriers. The TaqI genotypes, both TT and TC showed a markedly higher MRI severity grading level than CC genotype (both P<0.01, compared with CC genotype). CONCLUSION: Certain VDR polymorphism is related in the presence and severity of CSM in Chinese subjects.

The clinical features and surgical treatment of degenerative lumbar scoliosis: a review of 112 patients.

OBJECTIVE: To investigate the clinical features, radiological characteristics and surgical results of degenerative lumbar scoliosis (DLS). METHODS: One hundred and twelve cases of DLS treated surgically from June 2001 to February 2006 were retrospectively reviewed for clinical features, characteristics of nerve root compression and imaging presentations. According to the preoperative clinical manifestations and imaging findings, different surgical modalities were performed, including simple nerve decompression and decompression with short or long posterior fusion (less or more than three segments, respectively). RESULTS: The mean age of 47 male and 65 female patients was 54.7 years. Clinical manifestations included lower back pain (76.8%), radiculopathy (79.5%) and claudication (48.2%). Plain lumbar radiograph showed right scoliosis in 87 and left scoliosis in the other 25 cases; the Cobb angle was 10°-46°; the apex of scoliosis mostly located at L3 (48.2%); L3 and L4 nerve roots were usually compressed on the concave side and L5 and S1 nerve roots on the convex side. The Cobb angle and physiologic lordosis angle of patients who underwent multi-segment (>3 segments) fusion improved to a greater extent than did that of patients who had simple decompression without fusion. A mean 5.7-year follow-up showed that the average improvement in Oswestry disability index (ODI) scores was 32.6, 26.3 and 13.5 for long segment fusion, short segment fusion and simple decompression without fusion, respectively. CONCLUSION: Decompression surgery with or without fusion, the main purpose of which is to relieve nerve root compression and stabilize the spinal column, is an effective treatment for chronic DLS. The treatment should be individualized according to the patient's age, general and economic factors, severity of deformity and other coexisting lumbar degenerative disorders.

[Sagittal diameters measurements on MR of the cervical spinal cord in normal subjects].

OBJECTIVE: To offer normal reference of diameter of the cervical spinal cord and available diameter of cervical spinal canal and to screen scientific radiographic criteria to define and quantify cervical spinal cord disease. METHODS: The magnetic resonance images of 120 normal people had been measured. The data of diameters of cervical spinal cord, CSF, M, the ratio of diameters of cord and CSF, and the ratio of diameters of cord and M had been collected and statistical analysis was made. And the relationships between the data above and each of gender, the length of C-spine and age were evaluated. In addition, the ratio of diameters of cord and CSF, and the ratio of diameters of cord and M was evaluated. RESULTS: The study showed that in healthy people, the diameters of cervical spinal cord, CSF and M was larger in the males than in the females, decreased with age, and increased with the length of C-spine but the diameter of CSF. And the ratio of diameters of cord and CSF increased with age and not affected by the length of C-spine. However, the ratio of diameters of cord and M was not affected by age and the length of C-spine. CONCLUSION: The ratio of diameters of cord and M is not affected by individual variation and can be used to evaluate cervical spinal cord atrophy, compression and impaired in patients with cervical myelopathy and can be important information in looking for clinically critical points.

[Clinical characteristics and diagnosis of rheumatoid arthritis of upper cervical spine: analysis of 71 cases].

OBJECTIVE: To study the clinical characteristics and diagnosis of rheumatoid arthritis (RA) in the upper cervical spine. METHODS: The clinical data of 71 patients with RA in the upper cervical spine, 18 males and 53 females, aged 46.2 (23-76), with a mean duration of RA of 18.2 years (2 months-47 years) were retrospectively reviewed. Fifty-three patients received glucocorticoid for more than 3 months. In addition to routine examinations, all patients underwent plain X-ray film taking, CT and MRI scanning, and erythrocyte sedimentation rate, rheumatoid factor (RF) and antistreptolysin O testing. RESULTS: The symptoms of upper cervical spine appeared at 8.3 years (2 months-46 years) after the diagnosis of RA was confirmed. The clinical manifestations of RA in the upper cervical spine were intractable pain in craniocervical junction or radiating pain. Abnormal postures in the neck and Sherp-Purser's sign were positive in some patients. Progressive neurological dysfunction with the involvement of spinal cord, medulla, or some cranial nerves might gradually appear. Irregular destruction of bone with osteoporosis around the lateral and median atlantoaxial joint was a common finding in the X-ray films and CT scans. Instability of the atlantoaxial joint, including anterior atlantoaxial subluxation, posterior atlantoaxial subluxation and anterior-posterior atlantoaxial subluxation were found in 68 cases, while rotation subluxation was presented in 37 cases. Vertical migration of the odontoid was seen in 11 cases. RF was positive in 18 cases. MRI revealed that the cause of spinal cord compression was the bone tissue and soft tissue pannus. CONCLUSIONS: RA in the upper cervical spine is a common situation in the clinical settings. The key point in the diagnosis of this disease is the identification of instability in the atlantoaxial joint and assessment of the spinal neurological deficit. And a careful analysis of the natural history will further help to achieve a better treatment effect.

[Anterior radical decompression for severe ossification of the posterior longitudinal ligament in the cervical spine].

OBJECTIVE: To report the outcome of anterior radical decompression for the treatment of severe ossification of the posterior longitudinal ligament (OPLL) with an average occupying ratio exceeding 50% in the cervical spine. METHODS: From July 2002 to February 2006, 26 patients with cervical OPLL occupying ratio of the spinal cord exceeding 50% underwent anterior decompression and fusion. There were 18 males and 8 females. The average age was 59 years (ranged from 43 to 73 years) and the mean occupying ratio was (65 +/- 20)%; Before operation, the JOA score was 8.7 +/- 2.8, and the sagittal diameter of spinal cord was (25 +/- 7)%. The ossified ligament was classified into two groups, the base-open group and the base-closed group. The occupying ratio was measured on 3-D CT scans, and the sagittal diameter of the deformed spinal cord was measured at the narrowest level on sagittal T2-weighted MRI. All patients received anterior decompression with the ossified ligament removed completely. Among them, 10 cases underwent one level corpectomy combined with one level diskectomy, 3 cases underwent 2 level corpectomy, and the other 13 patients underwent one level corpectomy. The decompressed segments were reconstructed either with a iliac crest strut or a titanium cage, and an anterior locking plate was implanted to prevent graft extrusion in every patient. All patients were monitored with ECP during decompression. RESULTS: The occupying ratio decreased to (10 +/- 5)%, the sagittal diameter of spinal cord increased to (75 +/- 15)%, and the average diameter of spinal cord at the narrowest site increased 3 times after operation. The JOA score was 14.2 +/- 2.5, with an average improvement ratio of (61 +/- 24)%. Three patients accompanied with diabetes presented with temporarily neurological deterioration. There were two cases complicated with cerebrospinal fluid leaks but cured within 2 weeks after surgery. One case accompanied with diabetes underwent a second emergency reexploration for hematoma in the spinal canal which caused a dyspnea. CONCLUSIONS: Anterior radical decompression is an optimal method for the management of severe OPLL in the cervical spine. Higher rate of neuro-function recovery can be anticipated.

[Time of early death after cervical spinal cord injury].

OBJECTIVE: To investigate the distribution of time of early death in the patients with cervical spinal cord injury (CSCI). METHODS: The clinical data of 63 CECI patients, including demographics, mechanism of injury, cervical spinal cord injury level and severity, associated injury, radiographs, management, and the causes of death, the time from injury to hospitalization and the time from injury to death were retrospectively analyzed so as to detect the time and cause of early death. RESULTS: The 63 CDCI patients died in early stage. 27 of the 63 patients (42.8%) died within a week after CSCI; 43 patients (68.3%) died within two weeks after CSCI, 57 patients (90.5%) died within four weeks after CSCI, and 6 patients (9.5%) died after four weeks after CSCI. CONCLUSION: The peak time of death is a week after CSCI. The major time of death is two weeks after CSCI. 90.5% cases died within four weeks. Respiratory failure is the leading cause of early death in patients with CSCI.

[Surgical strategy for severe cervical spine dislocations].

OBJECTIVE: To evaluate the rate of open reduction and surgical strategy of severe cervical dislocation. METHODS: From March 2001 to March 2006, the data of 92 cases of cervical dislocation over 1/2 were retrospectively studied. Garden Well traction with 1 - 3 kg weight were performed before operation. The patients were performed with diskectomy and reduction with anterior approach initially, for those that can not be reduced, corpectomy were performed and reduction procedures were repeated. The posterior reduction and fixation were followed when reduction can not be reached with anterior approach only. The succeed rate of reduction, rate of tracheotomy were recorded and fusion rate, Frankel score and visual analog scale (VAS) were evaluated. RESULTS: Reduction succeed in 38 cases after diskectomy, 44 after corpectomy and 7 after combined anterior-posterior-anterior procedure. Three cases got incompleteness reduction. Tracheotomy was done in 29 cases. The Frankel score increased 0.5 degree and VAS was 2 averagely at the last follow-up. CONCLUSIONS: The succeed rate of anterior open reduction was 89.2%, and only 10.8% patients needs an additional combined posterior and anterior approach. For patients with completed spinal cord injury with dislocation above C(4), or with dislocation below C(5) but the edema on MRI T2 image are above C(4) level need tracheotomy. The operation be done until respiratory function stable. For patients with completed spinal cord injury with dislocation below C(4) and uncompleted spinal cord injury with dislocation above C(4), the rate of tracheotomy is relatively lower and early operation is recommended.