To cure patients suffering from atlanto-axial instability following old fracture of odontoid process concomitant with stenosis of lower end of cervical spinal canal, a new operative method was designed. It included atlanto-axial fusion by Gallie technique and resection of right half of the laminae of C3-C7 spine at one stage. A female of 63 years old was treated. She was admitted with neck pain and numbness of the upper and lower limbs. A history of neck injury was noted in enquiry. In physical examination showed the sensation of pain of the upper limbs was decreased and the muscle power of the upper and lower limbs ranged from III degree to IV degree. The X-ray film and MRI suggested that there was instability of the atlanto-axial joint with stenosis of 4th-6th cervical spinal canal. The operation was satisfactory. After operation, the patient was followed up for 11 months. The physical examination indicated that sensation of the upper limbs had recovered to normal and the muscle power of the upper limbs reached IV degree and that the lower limbs reached V degree and X-ray showed bony fusion of the atlanto-axial joint. The conclusions were: 1. The stability of atlanto-axial joint was reconstructed with expanding of the spinal canal at the same time. 2. The duration, risk and cost of the therapy were reduced, and maintenance of the stability of the cervical spine throughout whole period of treatment was recommended.
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 compare the biomechanical properties of the anterior transpedicular screw-artificial vertebral body (AVB) and conventional anterior screw plate system (AP) in lower cervical spine by finite element study. Methods CT images (C1-T1) were obtained from a 38-year-old female volunteer. The models of intact C3-7 (intact group), AP fixation (AP group), and AVB fixation (AVB group) were established and analyzed by Mimics 14.0, Geomagic Studio 2013, and ANSYS 14.0 softwares. The axial force of 74 N and moment couple of 1 N·m were loaded on the upper surface and upper facet joint surfaces of C3. Under conditions of flexion, extension, lateral bending, and rotation, the Von Mises stress distribution regularity and maximum equivalent stree of AP and AVB groups were recorded, and the range of motion (ROM) was also analyzed of 3 groups. Results The intact model of lower cervical spine (C3-7) was established, consisting of 286 382 elements and 414 522 nodes, and it was successfully validated with the previously reported cadaveric experimental data of Panjabi and Kallemeyn. The stress concentrated on the connection between plate and screw in AP group, while it distributed evenly in AVB group. Between AP and AVB groups, there was significant difference in maximum equivalent stress values under conditions of 74 N axial force, flexion, extension, and rotation. AVB group had smaller ROM of fixed segments and larger ROM of adjacent segments than AP group. Compared with intact group, whole ROM of the lower cervical spine decreased about 3°, but ROM of C3, 4 and C6, 7 segments increased nearly 5° in both AP and AVB groups. Conclusion As a new reconstruction method of lower cervical spine, AVB fixation provides better stability and lower risk of failure than AP fixation.
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.
ObjectiveTo evaluate the effectiveness of cervical disc replacement for cervical myelopathy. MethodsBetween October 2006 and October 2008, 20 patients (26 segments) with cervical myelopathy underwent single-level (14 segments) or bi-level (6 segments) cervical disc replacement. There were 8 males and 12 females with an average age of 46 years (range, 26-65 years). The disease duration ranged 2-18 months (mean, 7 months). The effectiveness was evaluated using visual analogue scale (VAS) score, cervical range of motion (ROM), and the Odom et al. criteria. Heterotopic ossification (HO), osteophyte formation, and prosthesis loosening were observed. ResultsAll incisions healed by first intention, with no severe complication. Twenty patients were followed up 30-48 months (mean, 34 months). At 28 months after operation, according to Odom et al. criteria, the results were excellent in 17 cases and good in 3 cases. The VAS scores of the neck, shoulder, and upper limb were significantly improved when compared with preoperative scores (P lt; 0.05). At 30 months after operation, X-ray films showed that 20 replaced segments were mobile and ROM was (10.6 ± 4.5)°, showing no significant difference (P gt; 0.05) when compared with that of upper adjacent segment (10.8 ± 3.7)° and lower adjacent segment (7.5 ± 4.2)°. HO occurred in 10 cases (13 segments). No displacement, subsidence, or loosening occurred except 1 case of retrodisplacement of the prosthesis. ConclusionCervical disc replacement can obtain good effectiveness. It can maintain normal cervical ROM and physiological curvature. But it needs further long-term follow-up to evaluate the function and the influence on the adjacent segments.
OBJECTIVE: To review the anatomic character of lower cervical pedicle, the placement and the biomechanical stability of the cervical pedicle screw fixation, the clinical application and the complication caused by fixation. METHODS: The literature concerned the cervical pedicle screw fixation in recent years were extensively reviewed. RESULTS: The cervical pedicle screw fixation can be widely used in the lower cervical spine instability according to the anatomic character of lower cervical pedicle, and the good biomechanical stability of the cervical pedicle screw fixation, and the complication can be controlled. CONCLUSION: The cervical pedicle screw fixation is an effective internal fixation for the lower cervical spine instability.
Objective To investigate the effect and safety of the anterior uncovertebral joint resection in treatment of cervical spondylotic myelopathy accompanied by radiculopathy. Methods From March 2002 toJuly 2004, 9 patients (5 males, 4 females; aged 38-66) with cervical spondylotic myelopathy accompanied by radiculopathy underwent the anterior uncovertebral joint resection and discectomy using the titanium cage implantation. There were 6 unilateral and 3 bilateral compressed nerve roots. Results During the follow-up for 3-16 months, CT scanning or X-ray films revealed thatall the patients improved with an enlargement of the intervertebral foramen, and MRI demonstrated that compression of the spinal cord and nerve roots vanished.Seven patients had a relief in the radicular pain although the other 2 still had a residual pain. All the patients improved to some extent in symptoms of myelopathy. No patient suffered vertebral artery injury during the operation. Conclusion The uncovertebral joint resection can directly decompressthe nerve roots. The key to avoidance of an injury to the vertebral artery is agood understanding of the regional anatomy and a good performance of the operation.