Effects of Cervical Fusion Surgery by Different Methods on Stability in Upper Cervical Spine with Jefferson Fracture / 医用生物力学

Objective To establish the finite element model of upper cervical vertebrae C0-3 with Jefferson fracture, and to analyze the influence of posterior atlantoaxial fusion (PSF) and occipitocervical fusion (OCF) on biomechanical properties of the vertebral body and mechanical conduction of the screw-rod system. Methods Based on CT images, the C0-3 segment Jefferson fracture model of human upper cervical spine was established. PSF, OCF1 and OCF2 internal fixation were performed according to surgical plan in clinic, and 50 N concentrated force and 1.5 N·m torque were applied to bottom of the occipital bone. The stress distribution and range of motion (ROM) of the cervical vertebral body, the maximum stress of the screw-rod system and the stress distribution of the intervertebral disc for C0-3 segment during flexion, extension, bending and rotation of the upper cervical spine were studied. Results Compared with PSF, the ROM of OCF1 and OCF2 vertebral bodies increased, and the stress of the nail rod decreased. OCF had a better fixation effect. Conclusions PSF, OCF1 and OCF2 fixation method can reduce the upper cervical ROM and restore stability of the upper cervical spine, which make stress distributions of the vertebral body and intervertebral disc tend to be at normal level. The research result can provide a theoretical basis for clinical surgery plan.

In vivo measurement of three-dimensional motion of the upper cervical spine using CT three-dimensional reconstruction / 中国骨伤

OBJECTIVE@#Using the CT three-dimensional reconstruction to measure the activity degree of atlanto-occipital joint and the atlantoaxial joint in different directions and its coupling movement in healthy volunteers, and three dimensional motion range of the maximum rotation position of the upper cervical spine of cervical spondylosis patients, and to analyze the differences, verifing the reliability of the method at the meantime.@*METHODS@#From January 2014 to June 2015, 20 healthy adult subjects(healthy adult group), and 26 patients with cervieal spondylosis(cervical spondylosis group) were selected. In healthy adult group, there were 11 males and 9 females, aged from 22 to 26 years old with an average of (24.0±1.2) years, and in cervical spondylosis group, there were 24 males and 2 females, aged from 36 to 72 years old with an average of (52.8±8.6) years. Healthy adults underwent CT examination in neutral position, maximum right rotation, maximum right lateral bending, maximum flexion and extention, and cervical spondylosis patients underwent CT examination in neutral position, maximum right rotation. Then the software Mimics was used to reconstruct occiput (Oc), atlas(C1) and axial(C2) vertebral three-dimensional image. Three virtual non-collinear markers were positioned on prominent structures of foramen magnum, C1 and C2. The 3D spatial coordinates of these virtual anatomical markers entail the definition of an anatomical local coordinate system which represent the position and orientation of the bones. Segmental motions were calculated using Eulerian angle in three major planes, and the difference between cervical spondylosis group and healthy adult group were compared. Due to the inaccuracy in anatomical landmark idenrification, two groups were measured 3 times, and the reliability of the experimental metnod was verified by the intra-group correlation (intra-group ICC) and the inter-group correlation coefficient(inter-group ICC).@*RESULTS@#Reliability verification results:the intra-group ICC and inter-group ICC results were all above 0.90, and the measurement method had high reliability. Three-dimensional activity of the upper cervical spine in healthy adults:the atlanto-occipital joint had(-6.8±1.5)° coupled left lateral bending and (8.9±2.0)° coupled extension in the maximum right rotation position, and the motion of atlanto-occipital joint had low activity[maximum was(5.3±2.6)°] in the remaining 3 positions; the rotation of atlanto-axial joint was(37.9±5.1)°, accounting for 52.34% of the total cervical spine activity[(72.4±5.0)°] in the maximum right rotation position, and rotational motion was still prominent in the remaining three positions. The relative translations of the upper cervical spine in all direction were small. The average axial rotation angle [(62.0±3.4)] ° of the total cervical spine in cervical spondylosis group was significantly lower than that in the healthy adult group, but the mean axial rotation angles of the atlanto-occipital and the atlantoaxial joint were not significantly different from those of the healthy adults(>0.05).@*CONCLUSIONS@#The three-dimensional CT reconstruction method has high reliability, which can be applied to measure the movement of spine. The upper cervical spine contributed the most to the direction of rotation, and the movement in all directions are accompanied by coupled motion in the other direction. There was no significant difference in the rotation of the upper cervical spine between cervical spondylosis patients and normal subjects.

Schwannoma of the upper cervical spine-a case report / 中华创伤杂志(英文版)

Upper cervical schwannoma is rare, and belongs to benign tumors that is usually asymptomatic. It accounted for only ten percent of schwannomas cases and mostly occurs in 40-50 years old patients. Aggressive and total resection is the treatment of choice for this tumor. Preoperative diagnosis is difficult, relying on clinical suspicion, and confirmed by surgical pathology. We report a 54-year-old male patient with chief complain of progressive weakness and numbness of his right arm for four months. He had a history of lymph node tumor in 2007 and excised in 2011. Neurological decrease was found on the right arm. The radiographic examination showed lytic lesion on the second, third, and fourth cervical spine. Computed tomography scan showed destruction extending to the first cervical vertebra. Capsulated extradural and extramedullary mass and compression to the spinal cord was found from the magnetic resonance imaging. Two-stage operation was performed. The first stage was posterior decompression with occipitocervical fusion and instrumentation, while the second was anterior decompression and iliac strut graft. Both operations performed using the surgical ultrasonic dissector. During three months' follow-up, it showed neurological improving. Neurological deficit appears when there is compression on the spinal cord. Total resection is the treatment of choice for these tumors. Preoperative imaging should be performed to exclude malignant tumor and found tumor extension.

Clinical effect of clivo-axial angle in posterior approach for patients with unstable upper cervical spine / 中国综合临床

Objective To investigate the clinical effect of clivo-axial angle(CAA)in the posterior approach for patients with unstable upper cervical spine.Methods Twenty-one patients with unstable upper cervical spine treated with posterior approach surgery from October 2014 to March 2016 were included in this study,and the patients were divided into the decompression group(11 cases)and the non-decompression group (10 cases)according to whether the intraoperative decompression was included.The clivo-axial angle(CAA) were measured by mobile three-dimensional before and after the surgery in order to estimate the reduction of spinal cord compression effect after the posterior cervical surgery combined with the reduction,fixation and bone graft fusion,then to guide the restoration.CT was used to measure the CAA and MR was used to measure the cervico-medullary angle(CMA)before operation and 3 months after operation.Japanese Orthopedic Association (JOA)scores was used to evaluate the neurological function 6 months after operation.Results All patients were followed up for 6-12 months.CMA((156.3±3.6°)vs.(155.9±2.7°))and CAA((154.3±5.1°)vs. (151.3±4.7°))of the decompression group and the non-decompression group at 3 months after surgery were improved significantly compared with those collected before the surgery(CMA:(131.5 ± 0.6°)vs.(131.1 ±0.5°);CAA:(133.2 ± 1.7°)vs.(132.4 ± 1.2°)),the differences were statistically significant(CMA: t=-21.81,P=0.00 vs.t=-28.54,P=0.00;CAA: t=-12.44,P=0.00 vs.t=-11.68,P=0.00).After operation,CAA((152.3 ± 1.3)vs.(132.6 ± 1.5))was significantly improved,compared with that before reduction((131.1±1.9)vs.(132.4±1.5°))(t=-30.09,P=0.00 vs.t=-35.93,P=0.00).JOA scores of the two groups at 6 months after operation((9.8±1.3)points vs.(10.3±1.7)points)were significantly lower than those before the surgery((7.1 ± 0.7)points vs.(7.6 ± 1.1)points),the differences were statistically significant(t=6.01,P=0.00 vs.t=4.36,P=0.00).No complications such as fixed failure,infection,spinal cord injury and vertebral artery injury were found in all patients.Conclusion For patients with upper cervical spine instability,the usage of intraoperative three-dimensional C arm scanning in CAA measurement to determine the effect of spinal cord compression can guide the reduction,simple and feasible,the clinical effect is satisfactory.

Application of preoperatively vertebral artery CTA in screw setting of upper cervical spine / 局解手术学杂志

Objective To study the application of cervical vertebral artery CT angiography(CTA) preoperatively in the screw setting of upper cervical spine.Methods The data of 170 patients who underwent upper cervical spine surgery from January 2014 to December 2015 in our hospital were retrospectively analyzed,of whom 80 cases with typeⅡodontoid fractures,90 cases with atlantoaxial dislocation;20 cases were operated with occipitocervical fusion,150 cases treated with atlantoaxial fusion.Seventy-eight cases were examinated by cervical vertebral artery CTA before sugery(observation group) but the other 92 cases(control group).The rate of the vertebral arterial lesion between the two groups were compared.Results Six cases with vertebral artery injury in control group,the incidence of arterial injury was 7％;unilateral vertebral artery was found in 3 cases,small congenital development of left cervical vertebral artery in 5 case,abnormal branch in 5 cases.The rate of dysplasia was 17％,and the rate of vertebral artery injury was 0.The rate of vertebral artery injury in control group was higher than observation group,the difference was significant(P<0.05).Conclusion Vertebral artery CTA examination preoperatively may become a routine examination,in order to make the operator carefully evaluate the relationship between the vertebral artery with atlantoaxial vertebral,choose the accurate screw-setting and avoid the vertebral artery injury in the upper cervical spine surgery.

Surgical Outcome for Hemodialysis-Related Upper Cervical Lesions

STUDY DESIGN: A retrospective study. PURPOSE: To investigate the surgical outcome for hemodialysis-related upper cervical lesions. OVERVIEW OF LITERATURE: Surgical outcome of lower cervical lesions in patients undergoing hemodialysis has been reported. However, surgical outcome for upper cervical lesions in hemodialysis patients is unclear. METHODS: Upper cervical lesions in nine patients undergoing hemodialysis were surgically treated. Mean age at surgery was 61.6 years (range, 52-68 years), and the mean follow-up period was 45.4 months (range, 2-98 months). Patients had undergone hemodialysis for an average of 25.3 years (range, 16-40 years) at surgery. Seven patients with destructive spondyloarthropathy (DSA) of the upper cervical spine were treated with atlantoaxial or occipitocervical fixation. Two patients with retro-odontoid pseudotumors were treated with C1 posterior arch resection alone. Japanese Orthopedic Association (JOA) scores for cervical myelopathy, postoperative complications, postoperative radiography, and preoperative and postoperative occipital pain were evaluated. RESULTS: Mean preoperative and postoperative JOA score was 3.7 and 8.1, respectively. The seven patients with DSA had severe preoperative occipital pain that disappeared postoperatively. Postoperative radiography showed solid bone union in DSA cases and no instability in pseudotumor cases. CONCLUSIONS: Satisfactory surgical outcome was observed for hemodialysis-related upper cervical lesions.

Upper Cervical Spine Injury / 대한척추외과학회지

Upper cervical spine injuries, including atlantooccipital articulation, are being recognized more commonly and there is an increasing number of reports of patients surviving with injuries previously thought to be fatal. The bony elements of the upper cervical spine consist of the occiput, atlas and axis. The nature of their articulations provides no inherent stability, but rather relies on ligaments to maintain the structural integrity. Some upper cervical injuries, occipitocervical injuries, and isolated midsubstance transverse ligament ruptures, are usually unstable and frequently result in neurological injury or death. Therefore, these injuries warrant early instrumented posterior arthrodesis. Most upper cervical spine injuries can be treated non-surgically and heal readily. Implementation of a diagnostic algorithm consisting of screening parameters gathered from the plain radiographs as well as routine CT and MRI scans in high risk patients should reduce the occurrence of missed injuries.

Discussion of internal fixation for the injury of upper cervical spine / 中国矫形外科杂志

Internal fixation technique is an important surgical method in cervical spine surgery.This article will introduce kinds of internal fixation techniques,discuss the differences and problems of them.Posterior screw-rod system and anterior odontoid screw technique have more advantages to provide solid fixation and high fusion rate in upper cervical trauma according to the latest reports.they are the effective and creditable surgical methods for reconstructing the stability of upper cervical spine.

Occipitocervical fusion with transpedicular fixation system / 中国矫形外科杂志

[Objective]To evaluate the effects of transpedicular internal fixation system for occipitocervical fusion.[Method]From Jan.2004 to Jan.2007,occipitocervical fusion was performed in 21 patients(12 male,9 female,mean age 45.3 years) with transpedicular internal fixation system(Sofamor Danek Company).There were 14 with upper cervical tumor,3 with cervical congenital malformation and 4 with dens axis fracture combined with atlantoaxial dislocation.The clinical outcomes were investigated by clinical observations,radiologic studies and statistical analysis.[Result]All the patients were followed up for 6 to 40 months with an average of 21 months.The result of X-ray showed that bony fusion was successful in 16 patients at 3 months and 5 patients at 6 months of follow-ups.There was no deterioration of spinal cord injury.The JOA scores of neurofunction increased from 5-17 points(mean 12.6 points) to 8-17 points(mean 15.8 points),with the improvement of 72%.All patients were partly limited in rotation movement.Seventeen patients had a rotatain of 100?,three was 80?,and one was 50?.[Conclusion]Transpedicular internal fixation system has multiaxial screw of three-column fixation and plastic rods,which offers strong fixation and good fusion.It can also benefit the maintenance of cervical curve.It is an effective and reliable method for reconstruction of upper cervical stability.

Atlanto-occipital Assimilation Can be Misdiagnosed as Atlantoaxial Dislocation: A Case Report

We present a rare case that atlanto-occipital assimilation can be misdiagnosed as C1-2 anterior subluxation. This is a lack of familiarity in orthopedic surgeon that was not used to manage the upper cervical spine injury. So the treatment of this entity need to get careful diagnosis and attention.

Treatment of Shoulder and Neck Pain in Patients with and without Upper Cervical Degeneration / 中国运动医学杂志

Objective To compare the results of clinical treatment of shoulder and neck pain in patients with and without upper cervical degeneration. Methods Fifty two patients with diagnosed shoulder and neck muscular fasciitis(with high tension and tenderness on the trapezius) were divided into 3 groups: group A,with upper cervical degeneration(16 cases);group B,with upper cervical degeneration(15 cases),and group C,without cervical degeneration(21 cases).There were no significant difference in gender,age and course of disease among the 3 groups.Patients in 3 groups were regularly treated by naprapathy and electric therapy(intermediate frequency).Cervical traction and manipulation was added to the patients in group A.Treatment for 3 groups lasted for 2 weeks.The Visual Analog Scale(VAS) scores and Odom criteria before and after treatment were used for determining the results of clinical treatment. Results The VAS scores after treatment were significantly improved in group A and group C as compared with that in group B(P=0.000).Odom criteria of group A(93.8%) and group C(95.2%) were excellent and good without significant difference(P=0.692),but they were significantly higher than that of group C(P=0.001). Conclusions Patients with shoulder and neck pain accompanied by upper cervical degeneration(narrowing of intervertebral foramen) should be treated with cervical traction and manipulation beside the routine therapy.