Objective To evaluate the clinical effect of Halo-vest in treatment of unstable upper cervical spine. Methods From March 1997 to October 2002, 16 cases of unstable upper cervical spineswere treated and immobilized by Halovest, aged from 14 to 53 years. There were 3 cases of isolated Jefferson fractures, 4 cases of isolated Hangman fractures and 1 case of Anderson type Ⅱ fracture. The 8 cases were immobilized for 3-4 months by Halovest. There were 3 cases of old odontoid fractures with dislocations treated by occipitocervical plate fixation and fusion, 1 case of C1 malignant tumor by posterior resection and internal fixation, 2 cases of C2 malignant tumor by anterior resection, fusion, and internal fixation; these cases were immobilized by Halo-vest during surgery. There were 1 case of C2,3 tuberculosis were treated by anterior debridement and fusion, and 1 case of gooseneck deformity by anterior decompression, fusion and screw fixation after resection of C2-7 , the 2 cases were immobilized for 3 months by Halo-vest.Of 16 cases, there were 8 cases accompanied with spinal cord syndrome. Results Fifteen cases were followed up 6 months to 5 years. Anterior arch ununion and posteriorarch osseous healing occurred in 1 case of Jefferson fracture. Other fractures and embedded bones became osseous fusion. One case of C2 malignant tumorrecurred 8 months after operation. Spinal cord syndrome of all patients disappeared. Conclusion Halo-vest immobilization is an effective method for conservative treatment and stable reconstruction of unstable upper cervical spine.
Objective To study operative methods of treating upper cervical spine instability without injury. Methods Twentythree cases were treated by internal fixation with autologous bone grafts. Atlantoaxial arthrodesis were performed in 10 cases with Apofix interlaminar clamp(5 cases), Atlas cable system(3 cases) and Brookes(2 cases). Occipitocervical fusion were performed in the other 13 cases by using of CD-cervical(3 cases), Cervifix(8 cases) and Ustick fixation(2cases). Results All the 23 cases were followed up for 2.5 years in average (ranged from 6 months to 5 years). Solid arthrodesis was obtained in all 23 cases . Six months after operation, of the 20 cases with preoperation nervous lesion, improvement was achieved in 16 cases. According to JOA standard and Hirabashiformula,the rate of improvement was 27.1%.Conclusion Posterior fusion is recommended for upper cervical unstability.
In order to check the neck response and injury during motor vehicle accidents, we developed a detailed finite element model for human cervical spine C4-C6. This model consisted of cortical bone, cancellous bone, annulus, nucleus, ligaments and articular facet, and it also set up contact in the contacting parts for simulating the movement perfectly under frontal impact. This model could be used for stress and strain distribution after the frontal impact load was applied on this model. During the process of frontal impact, the most displacement simulated data were in the interval range of experimental data. The experimental results showed that this model for the human cervical spine C4-C6 simulated the movement under the frontal impact with fidelity, and reflected the impact dynamics response on the whole.
Objective To explore the surgical feasibil ity and cl inical outcome of transpedicle screw fixation in treatment of atlantoaxial instabil ity and dislocation. Methods From January 2007 to June 2009, 16 patients with atlantoaxial instabil ity and dislocation were treated with transpedicle screw fixation. There were 13 males and 3 females, with a mean age of 42 years (range, 24-61 years). The transpedicle screw fixation was employed in 5 patients with old odontoid fracture (4 of Anderson type II and 1 of type III), in 4 patients with fresh odontoid fracture, in 4 patients with traumatic disruption of transverse atlantal l igament, and in 3 patients with congenital odontoid disconnection for atlantoaxial instabil ity. All patients had symptoms of cervical pain and l imition of cervical motion, 10 patients compl icated by dyscinesia and hypoesthesia of extremities. The Japanese Orthopaedic Association (JOA) score before operation was from 5 to 13, with an average of 8.5. The image examination showed atlantoaxial instabil ity or dislocation in all patients. Granulated autogenous il ium (20-30 g) was placed onto the surface of the posterior arches of both atlas and axis in some patients with old fracture of odontoid process or disruption of transverse atlantal l igament. Results The mean operative time and bleeding amount were 1.6 hours (1.2-2.5 hours) and 100 mL (50-200 mL), respectively. All the incision healed by first intension. All patients were followed up for 3-18 months, with an average of 11.5 months. The JOA score 3 months after operation was from 12 to 17, with an average of 14.2. All screws were successfully placed in atlas and axis. No postoperative compl ications such as vertebral artery injury, dural rupture, exacerbation of neurological symptoms, wound infection, and broken srews were observed in 16 cases. Postoperative radiograph and CT showed that only one screw penetrated into vertebral canal, but there was no neurological symptoms. Bony fusion was observed after 6 to 18 months of operation, and atlantoaxial rotational function in all patients restored satisfactorily, but axial rotation was partially lost. Conclusion Transpedicle screw fixation in upper cervical spine for treatment of atlantoaxial instabil ity and dislocation is safe and rel iable
This study aims to develop and validate a three-dimensional finite element model of inferior cervical spinal segments C4-7 of a healthy volunteer, and to provide a computational platform for investigating the biomechanical mechanism of treating cervical vertebra disease with Traditional Chinese Traumotology Manipulation (TCTM). A series of computed tomography (CT) images of C4-7 segments were processed to establish the finite element model using softwares Mimics 17.0, Geromagic12.0, and Abaqus 6.13. A reference point (RP) was created on the endplate of C4 and coupled with all nodes of C4. All loads (±0.5, ±1, ±1.5 and ±2 Nm) were added to the RP for the six simulations (flexion, extension, lateral bending and axial rotation). Then, the range of motion of each segment was calculated and compared with experimental measurements of in vitro studies. On the other hand, 1 Nm moment was loaded on the model to observe the main stress regions of the model in different status. We successfully established a detail model of inferior cervical spinal segments C4-7 of a healthy volunteer with 591 459 elements and 121 446 nodes which contains the structure of the vertebra, intervertebral discs, ligaments and facet joints. The model showed an accordance result after the comparison with the in vitro studies in the six simulations. Moreover, the main stress region occurred on the model could reflect the main stress distribution of normal human cervical spine. The model is accurate and realistic which is consistent with the biomechanical properties of the cervical spine. The model can be used to explore the biomechanical mechanism of treating cervical vertebra disease with TCTM.
A comprehensive, geometrically accurate, nonlinear C0-T1 three-dimensional finite element (FE) model was developed for the biomechanical study of human cervical spine and related disorders. The model was developed with anatomic detail from the computed tomography (CT) images of a 46-year old female healthy volunteer, and applied the finite element model processing softwares such as MIMICS13.1, Hypermesh11.0, Abaqus 6.12-1, etc., for developing, preprocessing, calculating and analysing sequentially. The stress concentration region and the range of motion (ROM) of each vertebral level under axial rotation, flexion, extension, and lateral bending under physiologic static loadings were observed and recorded. The model was proven reliable, which was validated with the range of motion in previous published literatures. The model predicted the front and side parts of the foramen magnum and contralateral pedicle and facet was the stress concentration region under physiological loads of the upper spine and the lower spine, respectively. The development of this comprehensive, geometrically accurate, nonlinear cervical spine FE model could provide an ideal platform for theoretical biomechanical study of human cervical spine and related disorders.
ObjectiveTo measure anatomical parameters related to cervical uncovertebral joint and provide data support for the design of uncovertebral joint fusion cage.MethodsAccording to the inclusion and exclusion criteria, raw DICOM data of cervical CT scan in 60 patients (30 males and 30 females, aged 39-60 years) were obtained, then the three-dimensional cervical spine model was reconstructed for anatomical measurement by using the Mimics19.0 software. The height of the uncinate process, the length of the uncinate process, the width of the uncinate process, and the length of the uncovertebral joint in the intervertebral foramen region were measured bilaterally from C3 to C7. The anterior and posterior distances between the uncinate processes were measured from C3 to C7. The height of the uncovertebral joint space, the central height of the intervertebral disc space, and the depth of the intervertebral disc space were also measured from C2, 3 to C6, 7. The mean, standard deviation, maximum, and minimum were calculated by using the SPSS22.0 statistical software for the design of uncovertebral joint fusion cage.ResultsThe height of the uncinate process, the length of the uncinate process, the width of the uncinate process, and the length of the uncovertebral joint in the intervertebral foramen region of C3-C7 and the height of the uncovertebral joint space of C2, 3-C6, 7 showed no significant difference between two sides (P>0.05). The height of the uncovertebral joint space also had no significant difference between females and males (P>0.05). The anterior distances between the uncinate processes of C3-C7 were significantly larger than the posterior distances between the uncinate processes (P<0.05), the uncovertebral joint presented a posterior cohesive shape. The central height of the intervertebral disc space in male group was slightly higher than that in female group, and the differences were significant (P<0.05) at C2, 3 and C5, 6; the depth of the intervertebral disc space in male group was significantly higher than that in female group (P<0.05). The central height of the intervertebral disc space was (4.94±0.49) mm (range, 3.81-5.90 mm), the depth of the intervertebral disc space was (15.78±1.23) mm (range, 12.94-18.85 mm), the anterior and posterior distances between the uncinate processes were (17.19±2.39) mm (range, 13.39-24.63 mm) and (10.84±2.12) mm (range, 7.19-16.64 mm), respectively. According to the results of the anatomical research, the height of the uncovertebral joint fusion cage was designed as 5, 6, 7, and 8 mm; the depth of the uncovertebral joint fusion cage was designed as 12, 13, 14, 15, and 16 mm; the width of the uncovertebral joint fusion cage was designed as 14-18 mm; and the two wings are designed as arc-shape with 2 and 3 mm in width.ConclusionThere are certain differences in the anatomical parameters of the uncovertebral joint between different segments. The uncovertebral joint fusion cage that designed based on the results of anatomical research is suitable for most patients.
ObjectiveTo evaluate the effectiveness of modified recapping laminoplasty preserving the continuity of supraspinous ligament in the treatment of intraspinal benign tumors in upper cervical vertebrae and its influence on the stability of the cervical vertebrae. MethodsThe clinical data of 13 patients with intraspinal benign tumors in upper cervical vertebrae treated between January 2012 and January 2021 were retrospectively analyzed. There were 5 males and 8 females, the age ranged from 21 to 78 years, with an average of 47.3 years. The disease duration ranged from 6 to 53 months, with an average of 32.5 months. The tumors located between C1 and C2. Postoperative pathology showed 6 cases of schwannoma, 3 cases of meningioma, 1 case of gangliocytoma, 2 cases of neurofibroma, and 1 case of hemangioblastoma. During operation the continuity of the supraspinal ligament were retained, the lamina ligament complex was lifted to expose the spinal canal via the approach of the outer edge of the bilateral lamina, and the lamina was fixed after the resection of the intraspinal tumors. Before and after operation, the atlantodental interval (ADI) was measured on three-dimensional CT; the effectiveness was evaluated by Japanese Orthopaedic Association (JOA) score, the neck dysfunction index (NDI) was used to evaluate the cervical function, and the total rotation of the cervical spine was recorded. Results The operation time was 117-226 minutes (mean, 127.3 minutes); the intraoperative blood loss was 190-890 mL (mean, 227.8 mL). The tumors were completely removed in all patients. There was no vertebral artery injury, aggravation of neurological dysfunction, epidural hematoma, infection, or other related complications. Two patients occurred cerebrospinal fluid leakage after operation, which were healed through electrolyte supplement and local pressure treatment of incision. All the patients were followed up 14-37 months, with an average of 16.9 months. Imaging examination showed no recurrence of tumor, displacement of vertebral lamina, loosening and displacement of internal fixator, and secondary reduction of vertebral canal volume. At last follow-up, JOA score significantly improved when compared with preoperative scores (P<0.05). Among them, 8 cases were excellent, 3 cases were good, and 2 cases were medium, with an excellent and good rate was 84.6%. There was no significant difference in ADI, total rotation of the cervical spine, and NDI between pre- and post-operation (P>0.05). ConclusionThe treatment of intraspinal benign tumors in upper cervical vertebrae with modified recapping laminoplasty preserving the continuity of the supraspinous ligament can restore the normal anatomical structure of the spinal canal and maintain the stability of the cervical spine.
Zero profile cervical interbody cage is an improvement of traditional fusion products and necessary supplement of emerging artificial intervertebral disc products. When applied in Anterior Cervical Decompression Fusion (ACDF), zero profile cervical interbody cage can preserve the advantages of traditional fusion and reduce the incidence of postoperative complications. Moreover, zero profile cervical interbody cage can be applied under the tabu symptoms of Artificial Cervical Disc Replacement (ACDR). This article summarizes zero profile interbody cage products that are commonly recognized and widely used in clinical practice in recent years, and reviews the progress of structure design and material research of zero profile cervical interbody cage products. Based on the latest clinical demands and research progress, this paper also discusses the future development directions of zero profile interbody cage.
ObjectiveTo investigate the feasibility of one-stage total spondylectomy by anterior and posterior approaches for treating solitary plasmacytoma (SP) of cervical spine.MethodsBetween June 2000 and March 2015, the clinical data, diagnosis, and treatment of 12 patients with SP of cervical spine were retrospectively analyzed. There were 8 males and 4 females, with a mean age of 46 years (range, 28-74 years). The mean disease duration was 8.4 months (range, 3-15 months). There were 2 cases in C2 segment, 4 cases in C3, 2 cases in C4, 1 recurrent case in C5, C6, and 3 cases in C7. According to WBB (Weinstein-Boriani-Biagini) surgical staging system, the tumor mainly occupied the vertebral body areas and expanded outside to 4 or 9 radiating zone in 8 cases, expanded both outsides to 4 or 9 radiating zones in 4 cases; 7 cases of them affected A to D layers, other 5 cases affected B to D layers. Preoperative Frankel system showed grade B in 1 case, grade C in 6 cases, and grade D in 5 cases. One vertebra segment was involved in 11 cases, and 2 vertebra segments were involved in 1 case. The unilateral vertebral artery was involved in 4 cases and bilateral vertebral artery in 1 case. One-stage total spondylectomy by anterior and posterior approaches for SP of cervical spine was applied in all patients, which all received adjuvant radiotherapy postoperatively. The operation time, intraoperative blood loss, complications, Frankel system, and visual analogue scale (VAS) score were recorded and analyzed.ResultsThe operation time was 6.8-9.3 hours (mean, 7.2 hours), and the intraoperative blood loss was 1 100-2 600 mL (mean, 1 600 mL). Esophageal leakage occurred in 1 patient with C5, C6 recurrent SP at 1 week after operation and 1 case presented with fat liquefaction of wound, who were cured by symptomatic treatment. Other patients showed no neurological deficit, major vascular injury (especially vertebral artery), phrenic nerve injury, superior laryngeal nerve injury, laryngeal nerve injury, respiratory failure, or other complications. All the 12 patients were followed up 27-98 months (mean, 58 months). The symptoms of spinal cord compression disappeared or improved after operation. At last follow-up, the nerve function was recovered to Frankel grade E in all patients; the VAS score decrease to 1.1±0.7, showing significant difference when compared with preoperative value (6.7±2.7) (t=2.485, P=0.014). Two patients had local recurrence at 29 months and 37 months after operation respectively, which were treated with adjuvant chemotherapy. One of them finally progressed to multiple myeloma and died of multiple organ failure after 43 months, the other one survived with residual tumor. One case presented with internal fixator loosening and breaking at 4 years after operation, who was performed revision surgery. The other patients had no tumor recurrence or malignant change during the follow-up, no complication such as internal fixator loosening or breaking occurred.ConclusionFor patients with SP of cervical spine, surgical intervention is an acceptable treatment option. One-stage total spondylectomy by anterior and posterior approaches can decline the local recurrence and relieve the symptoms of spinal cord compression, so as to improve patients’ life quality. However, patients with progression to multiple myeloma should be treated with individualized therapeutic regimen, and the prognosis may be poor.