Objective To develop a high-accuracy, better-safety and low-cost cervical pedicle locator system for guiding cervical pedicle screw placement. Methods Cervical pedicle screw locator system was made of stainless steel. Ten cervical specimens from voluntary donation were divided into two groups according to compatibil ity design: control group inwhich 60 screws were planted into C2-7 by free hand; and experimental group in which 60 screws were planted into C2-7 under the guidance of three-dimensional locator system. The condition of screw insertion was observed and the accuracy was evaluated by the integrity of pedicle walls. Results In the control group, 32 screws (53.33%) were placed inside the pedicles and 28 (46.67%) were outside; 9 screws (15.00%) led to nerve root injury, 5 screws (8.33%) caused vertebral artery injury and no spinal cord injury occurred; and the qual ification ratio of screw insertion was 76.67% (excellent 32, fair 14, poor 14). While in the experimental group, 54 screws (90.00%) were placed inside the pedicles and 6 (10.00%) were outside; 1 screw (1.67%) caused vertebral artery injury and no nerve root injury and spinal cord injury occurred; and the qual ification ratio of screw insertion was 98.33% (excellent 54, fair 5, poor 1). There was significant difference between the two groups (P lt; 0.05). Conclusion Cervical pedicle screw locator system has the advantages of easy manipulation, high accuracy of screw placement and low cost. With further study, it can be appl ied to the cl inical.
Objective To study the prevention and management of early compl ications associated with anterior cervical spinal surgery. Methods From November 1998 to December 2006, 363 cases were treated with anterior cervicalsurgery, including 268 males and 95 females aged 17-79 years．In these cases, 224 suffered from cervical spondylosis, 39 from cervical disc herniation, 87 from cervical trauma, 9 from cervical tumor and 4 from cervical tuberculosis. Forty-eight cases with anterior cervical surgery were fused by autogenous il iac bones, 132 cases with anterior cervical surgery were fused by autogenous il iac bones and anterior cervical spine locking plates, and 183 cases with anterior cervical surgery were fused by titanium mesh cage and anterior cervical spine locking plates. Results A total of 282 cases were followed up for 3 months to 5 years with the average of 1 year and 11 months. Twenty-three compl ications associated with surgery were found, with an incidence of 8.16%. Three cases of transient superior laryngeal nerve palsy recovered within 3-7 days after the restriction of l iquid diet and fluid replacement. Two cases of recurrent laryngeal nerve palsy recovered by 3-month pronunciation practice. One case of spinal cord injury was treated with medicine for dehydration and anti-inflammation, and was restored to preoperative muscle power of inferior extremity after 6 months. Two cases of CSF leakage were cured with moderate local compression and meticulous water-tight wound closure. Among the 10 patients with compl ications of internal fixation, one suffering mild dysphagia was reoperated, while the others were treated with cephal-cervico-thorax plaster external fixation and recovered with sol id fusion within 3-18 months. Among the 4 cases with cervical hematoma, 1 died of wrong rescue procedures and 1 was infected. Conclusion Adequate preoperative preparation, thorough understanding of anatomy related to the anterior approach and skilled surgical technique are essential for preventing the early postoperative compl ications of anterior cervical spinal surgery．
Objective To evaluate the fixation technique of using the cervical lateral mass plate in the cervical posterior approach operation. Methods Eight patients in this group were admitted from September 2001 to November 2006. Among the 8 patients, there were 6 males and 2 females, with their ages ranging from 28 to 78 years. Cervical vertebral fracture with dislocation was found in 4 patients, C2 spinal cord injury in 1, C1 fracture in 1, cervical spinal stenosis in 1, and C2-5 spinal cord neurofibroma in 1. Muscle strength 3-4. TheFrankel grading system was usedin 6 patients with traumatic injury. Before operation, Grade C was observed in 2patients，Grade D in 3，and Grade E in 1. All the operations were performed according to requirements of the Margel’s method. We positioned 40 screws in all the patients, including 4 screws at C2，6 screws at C3，12 screws at C4，4 screws at C5，4 screws at C6，2 screws at C7，and 6 screws at T1. Results The followingup for an average of 14.1 months (range,645 months) revealed that there was no malposition of the screws in the patients. One of the 8 patients developed spinal instability in the fixed segment at 3 months after operation. The headchestbrace was applied to the patient for 3 months, and the spinal fusion was achieved. The further followingup to 45 months indicated that there was no instability occurring. The remaining patients recovered to their spinal stability by the spinal fusion. The patients also recovered in their neurological function after operation. The Frankel assessment showed that 1 patient had Grade E, 3 from Grade D to Grade E, 1 from Grade C to Grade D, and 1 from Grade C to Grade E. Conclusion The cervical lateral mass plate fixation can provide the immediate and b segmental immobilization for the good cervical spine stability.
Objective To explore changes in the height and width of the cervical intervertebral foramina of C6,7 before and after the C5,6 discetomy, the replacement or the anterior intervertebral fusion so as to provide the theoretical basis for the clinical practice. Methods Eleven fresh cervical spinal specimenswere obtained from young adult cadavers. The specimens of C5,6 were divided into the integrity group, the discectomy group, the artificial disc replacement group, and the intervertebral fusion group. The range of variety (ROV) of the C6,7 intervertebral foramen dimensions (height, width) before and after the loading tests (0.75, 1.50 Nm) were measured in the 4 groups. Results The C6,7 intervetebral foramen height and width increased significantly during flexion (Plt;0.01) but decreased significantly during extension (Plt;0.01). There was a significantdifference between the two test conditions in each of the 4 groups (Plt;0.01). However, in the two test conditions there was no significant difference in ROV of the C6,7 intervetebral foramen height and width during flexion and extension betweenthe integrity group, the discectomy, and the artificial disc replacement group（Pgt;0.05）, but a significant difference in the above changes existed in the intervertebral fusion group when compared with the other 3 groups (Plt;0.05). In the same group and under the same conditions, the ROV of the C6,7 intervetebral foramen height and width was significantly different in the two test conditions (Plt;0.01). Conclusion The results have indicated thatartificial disc replacement can meet the requirements of the normal cervical vitodynamics. The adjacent inferior cervical intervetebral foramen increases during flexion but decreases during extension. The intervertebral fusion is probably one of the causes for the cervical degeneration or the accelerated degeneration and for the cervical spondylotic radiculopathy and the brachial plexus compression.
Objective To evaluate the therapeutic effect of open-door cervical expansive laminoplasty (ELP) with anchor fixation on flurosis cervical stenosis (FCS). Methods From February 2005 to February 2006, 20 patients with FCS underwent ELP using anchor fixation (group A) and 24 patients with FCS received ELP using conventional silk thread fixation (group B). In group A, there were 11 males and 9 females aged (58.0 ± 11.2) years old, the course of disease ranged from 6 months to 5 years, and the stenosis involved 3 vertebral levels in 3 cases, 4 levels in 8 cases, and 5 levels in 9 cases, andthe sagittal diameter of the cervical spinal canal was (7.30 ± 5.23) mm. While in group B, there were 11 males and 13 females aged (61.0 ± 9.1) years old, the course of disease ranged from 5 months to 5 years, the stenosis involved 3 vertebral levels in 5 cases, 4 levels in 10 cases, and 5 levels in 9 cases, and the sagittal diameter of the cervical spinal canal was (7.11 ± 4.92) mm. No significant differences were evident between two groups in terms of the general information (P gt; 0.05). Before operation and at 24 months after operation, the nerve function was assessed by JOA score, the axial symptom (AS) was evaluated using Chiba 12-point method, and the changes of cervical lordosis index (CLI) and cervical range of motion (CRM) were detected by imaging examination. Results All wounds healed by first intention. All patients were followed up for 24 months. JOA score: in group A, it was improved from 7.4 ± 1.5 before operation to 14.6 ± 2.1 at 24 months after operation with an improvement rate of 61% ± 3%; in group B, the score was increased from 7.1 ± 2.2 to 12.6 ± 2.5 with an improvement rate of 52% ± 5%; significant differences were evident in two groups between before and after operation, and between two groups in terms of the improvement rate (P lt; 0.05). AS score: in group A, it was improved from 6.2 ± 2.1 before operation to 10.8 ± 0.3 at 24 months after operation with an improvement rate of 74% ± 4%; in group B, the score was increased from 6.3 ± 1.9 to 8.8 ± 0.5 with an improvement rate of 39% ± 3%; significant differences were evident in two groups between before and after operation, and between two groups in terms of improvement rate (P lt; 0.05). X-ray films and CT scan at 24 months after operation displayed that there was no occurrence of “breakage of door spindle” or “re-close of door” in two groups, there was no occurrence of anchor loosing in group A, and the molding of the spinal canal was satisfactory in two groups. Preoperatively, the CLI was 11.9 ± 1.9 in group A and 11.3 ± 2.2 in group B and the CRM was (39.5 ± 2.4)° in group A and (40.2 ± 1.8)° in group B. While at 24 months after operation, the CLI was 9.5 ± 2.2 in group A and 8.2 ± 2.8 in group B, and the CRM was (30.6 ± 2.0)° in group A and (28.7 ± 2.4)° in group B, suggesting there was a significant decrease when compared with the preoperative value and group A was superior to group B (P lt; 0.05). The saggital diameter of the cervical spinal canal 24 months after operation was (13.17 ± 2.12) mm in group A and (12.89 ± 3.21) mm in group B, indicating there was a significant difference when compared with the preoperative value (P lt; 0.01). Conclusion Compared with conventional silk thread fixation, ELP using anchor fixation brings more stabil ity to vertebral lamina, less invasion to the posterior muscular-skeletal structure of the cervical spine, sl ight postoperative neck AS, andsatisfactory cl inical outcomes.
Objective To summarize the methods andskills of anterior cervical locking plate systems in clinical application and to analyze the causes of some complications as well as give some preventive or remedial countermeasures. Methods From 1998 to 2002, 159 patients with cervical spondylotic myelopathy,fracturedislocation,tumor or tuberculosis of the cervical spine were treated with anterior locking plate systems. The complications were reviewed and analyzed. Results Ten kinds of complications related to anterior locking plate systems occurred in 21 patients. Most of the complications were caused by improperly-selecting implants, experience and technique deficiency. Conclusio The important preventive or remedial countermeasures are correctly-selecting patients, meticulous preoperative preparation, properly-selecting implants, standard and skillful manipulation and rational postoperative protection.
Objective To investigate the treatment methods and the cl inical therapeutic effects of symptomatic cervical vertebral hemangioma associated with cervical spondylotic myelopathy. Methods A retrospective analysis was performed in 18 patients (10 males and 8 females, aged 30-62 years with an average age of 45.3 years) with cervical vertebral hemangioma associated with cervical spondylotic myelopathy between January 2006 and September 2008. The disease duration was 10-26 months (mean, 15.6 months). All patients had single vertebral hemangioma, including 2 cases at C3, 3 cases at C4, 5 cases at C5, 5 cases at C6, and 3 cases at C7. The X-ray films showed a typical “pal isade” change. According to the cl inical and imaging features, there were 13 cases of type II and 5 cases of type IV of cervical hemangioma. The standard anterior cervical decompression and fusion with internal fixation were performed and then percutaneous vertebroplasty (PVP) was used. The cervical X-ray films were taken to observe bone cement distribution and the internal fixation after operation. The recovery of neurological function and the neck pain rel ief were measured by Japanese Orthopaedic Association (JOA) score and visual analogue scale (VAS) score. Results All operations were successful with no spinal cord and nerves injury, and the incisions healed well. Anterior bone cement leakage occurred in 2 cases without any symptoms. All cases were followed up 24-28 months (mean, 26 months) and the symptoms were improved at different degrees without fracture and collapse of vertebra or recurrence of hemangioma. During the follow-up, there was no implant loosening, breakage and displacement, and the mean fusion time was 4 months (range, 3-4.5 months). The JOA score and VAS score had a significant recovery at 3 months and at last follow-up when compared with preoperative values (P lt; 0.05). Based on JOA score at last follow-up, the results were excellent in 9 cases, good in 6 cases, fair in 2 cases, and poor in 1 case. Conclusion The anterior cervical decompression and fusion with internalfixation combined with PVP treatment is one of the ideal ways to treat symptomatic cervical vertebral hemangioma associated with cervical spondylotic myelopathy, which could completely decompress the spinal cord and effectively alleviate the cl inical symptoms caused by vertebral hemangioma.
Objective To compare the loss of anterior column heightand cervical Cobb angle with three different types of anterior cervical discectomy and fusion(ACDF). Methods A prospective randomized study was performed on 60 patients who had undergone ACDF with the autologous iliac crest graft (group A, n=20), the autogenous bone and the anterior cervical locking plates (group B, n=20), and Syncage-C filled with the local autograft reamings (group C, n=20) from January 1998 to January 2003. The patients diagnosed as having cervical radiculopathy (RP) and cervical spondylotic myelopathy (CSM) were indicated for ACDF. Of the patients, 41 were male and 19 female with a mean age of 57 years (range, 36-68) and their average course of disease was 6.2 months (range, 1-36). There were 36 one-level and 24 two-level fusions from C3,4 to C7,T1. Radiological measurements were performed on the cervical radiographs taken before operation, 7 days and 3 months after operation, and on the last day of the follow-up; then, the height and Cobb angle of the fused segment, functional restoration, and clinical outcome were evaluated in the three groups. Results The followup of more than 2 years (range,2-7) showed that the average loss of anterior column height and Cobb angle of the fused segments in groups A and B, which had not preserved the-endplate, hada greater increase than that in group C, which had preserved the endplate. Of the patients, 12 had autograft collapse, 3 autograft displacement, and 10 postural abnormality between the fused segments, most of which happened in groups A andB. The fusion rate was 93.3% (56 cases) according the strict arthrodesis critera; their excellent and good rate in the functional assessment was 83.3% (RP 90.4%, CSM 79.5%); the overall satisfactory (excellent and good) rates in groups A,B and C were 75%, 85% and 90%, respectively. Conclusion To increase the resistance to graft subsidence, which is a major reason for narrowness of the fused segments, and to maintain normal cervical curvature, we should improve our skills of bone grafting performance, preserve the endplate, carefully evaluate the degree of osteoporosis before operation, and use anterior cervical locking plate and /or fusion with Syncage-C when necessary.
OBJECTIVE: To discuss the value of anterior operation in fracture-dislocation of connect of cervical vertebrae and thoracic vertebrae. METHODS: From 1997, 21 patients with fracture-dislocation of connect of cervical vertebra and thoracic vertebrae were operated on. The interval between injury and operation was within 24 hours in 4 cases, 2-7 days in 9 cases, 8-14 days in 3 cases and within 4 weeks in 5 cases. The locations were C6,7 in 7 cases, C7 in 9 cases and T1 in 5 cases. The nerves function of spinal of all the cases have different degrees of injury. Classification of Frankel were the following: 3 cases of grade A, 6 cases of grade B, 9 cases of grade C, and 3 cases of grade D. The operative procedure included the following: anterior operation of cervical vertebrae; incision of most fracture vertebral body to decompress; transplantation of ilium bone grafting fusion; and internal fixation of anterior cervical vertebrae with locking-steel. RESULTS: In 21 patients, 1 died of accompanying by pulmonary infection; 20 were followed up 8 months to 3 years with an average of 21 months. All transplanted ilium had fused. The nerve function of spinal cord had recovered in different degrees(2 cases of grade A, 1 case of grade C, 9 cases of grade D and 8 cases of grade E); the turn of vertebral column was normal. No internal fixation failed. CONCLUSION: Anterior operation is a better way to treat fracture-dislocation of connect of cervical vertebrae and thoracic vertebrae with easy operation, less complications, satisfactory reduction of fracture and good stability.