Complications of anterior approach to the cervical spine ara encountered during exposure,spinal procedure, interbody fusion and the postoperative period. 200 cases of such operative procedure observed by the authors are analyzed, and they are divided into following two types:1.Operative injuries: Include the following:(1)Recurrent laryngeal nerve palsy;(2) Homer's syndrome; (3) spinal cord and nerve root injury; (4) cere-brospinal fluid fistula; (5) sleepinduced apnea, and others.2. Postoperative complications include: (1) postoperative hematoma; (2) failure of bony fusion, nonunion and anterior angulation deformity; (3) laryngo-spasm; (4) infection of the operative wound; (5) persistent pain of the iliac donor site.It is the opinion of the authors that the anterior approach to the cervical spine invites less serious complications than the posterior approach, and It should be employed more extensively for degenerative and traumatic disorders of the cervical spine.

Objective: To observe the decompressive effect of laminectomy on the spinal cord compressed anteriorly in the cervical spine. Methods : The compression of the cervical spinal cord-meningeal complex was simulated using a small transducer pushed into the spinal canal in 7 whole cadaver spines. The depth of canal occlusion was controlled depending on 20%, 30% and 40% of the saggital diameter of the canal. The distribution and the change of the stress on the spinal cord-meningeal complex and the displacement of dural sac were recorded before and after laminectomy. Results: When the anterior transducer was pushed into the spinal canal with 40% occlusion, the force was 3.86 kPa on the anterior wall and 0.38 kPa on the posterior wall of the spinal cord-meningeal complex respectively. After extensive laminectomy, the anterior compressive force decreased 6.06% - 14.38% and the displacement of the posterior dura wall was 0.44 mm. Conclusions: The anterior compressive force was mainly absorbed by the anterior part of the spinal cord-meningeal complex. Extensive laminectomy had no significant decompressive effect on the spinal cord compressed anteriorly inthecervical spine.

Objective To study the causes, technique, selection and results of revision surgery in the patients with cervical spondylosis after anterior decompression. Methods Twenty nine patients with cervical spondylosis were treated with revision surgery after anterior decompression. Among them, there were 19 patients with cervical myelopathy, 8 with combination of myelopathy and radiculopathy, and 2 with radiculopathy only. The procedures included removal of the residual compressive elements, migrated bone grafts and implants, and refusion with bone graft and internal fixation. Depending on the clinical symptoms and findings of physical examination, X ray films and MRI were used to analyze the causes and the results of the revision surgery. Results There were 11 patients with incomplete initial decompression, 4 patients with the migration of the bone graft, 4 patients with new neural compression after cages interbody fusion, 2 patients with loose and migration of the plates and 8 patients with the degenerative changes in adjacent segments. Solid fusion in 23 cases and delayed fusion in 6 cases were observed during follow up. The neural recovering rate after the revision surgery was 52.4% in the patients with cervical myelopathy and 46.7% in the patients with combination of myelopathy and radiculopathy. Conclusion The main causes for the reoperation after anterior decompression were residual or newly formed neural compression. The complete decompression and segmental stabilization in the cervical revision surgery was essential for obtaining the good results.

BACKGROUND: It is difficult to conduct the operation of ossification of ligamentum flavum (OLF) in thoracic spine, and the operation needs complecated operative skill, and unmerited disposal tends to worsen neurological dysfunction.OBJECTIVE: To analyze the operative method for OLF of thoracic spineand functional restoration.DESIGN: Case analysis.SETTING: Department of Orthopaedics, Changzheng Hospital, SecondMilitary Medical University of Chinese PLA.PARTICIPANTS: Totally 56 patients with OLF of thoracic spine, whowere treated at the Department of Orthopaedics, Changzheng Hospital fromAugust 1996 to August 2003.METHODS: The operative therapy was performed in all the patients, and the method was determined by the results of MRI and CT examination: ①The 19 patients, whose OLF in thoracic spine was focal type, and range of lesion did not exceed two segments, were treated with simple resection and decompres sion in posterior wall of vertebral canal. ②Fenestration and sledging-allocating manipulation in the whole piece unilateral lamina of vertebra were carried out in 29 cases involving more than 2 segments. ③If coplanar OLF in thoracic spine combined with protrusion of thoracic spine disc or ossification of posterior longitudinal ligament, decompression of posterior midline approach+posterior lateral approach was performed, totally 8 cases.MAIN OUTCOME MEASURES: Post-operation functional restoration was evaluated with Epstein standard, excellent: recovery of sensation and exercise was near to normal; good: spinal cord function was improved significantly, and permitted to walk with brace; fair: small partial restoration of sensory and motor function, unable to walk; bad: Inefficiency or becoming severe.RESULTS: A total of 55 cases were followed up for more than one year and 1 case only for two months after operation. ①Functional restoration: excellent: 39 cases; good: 8 cases; fair: 5 cases; bad: 4 cases. ②Symptom recovery after operation was confirmed by disappearance of tight sensation, reduction of muscular tension, relieving of numbness in order. ③The recovery was rapid for 3 to 6 months after operation. Part of patients' condition was still ameliorating during one year after operation, and rare advancement 2 years later. The recovery of complete paraplegics was bad, so was the severe paraplegia with long history. CONCLUSION: Compressive myelopathy caused by OLF in thoracic spine should be treated in an earlier period by operation. Resection and decompression of posterior wall of thoracic spine and decompression of posterior approach could be choosed according to different condition.

Objective: To synthesize the collagen-GAG template and to evaluate its feasibility to be used as the MSCs vehicle for meniscal tissue engineering. Methods: The collagen-GAG template was synthesized from rat tail type Ⅰ collagen and GAG using Yannas method. Then the post-stimulated MSCs by bFGF and TGF-β1 were added in. The MSCs-enriched collagen sponges were cultured in vitro， two weeks later the histological and ultrastructure detection was performed. Results: The histological and ultrastructure of the collagen-GAG template remained intact after 2 weeks' culture, and the MSCs in it remained viable. Conclusion: The collagen-GAG template synthesized in this experiment is suitable for the meniscal tissue engineering reconstruction as the vehicle for MSCs seed cells.

One hundred and seven patients with lumbar disc hefniation and lumbar stenosis with poor operative results are presented in this paper. According to clinical manifestation and imaging features, appropriate treatment modality was selected for each patient. Seventy-two cases were reoperated, among which excellent and good results were obtained in 60 cases (83.3%). Thirty-five patients were treated with conservative method, 28 cases improved and 7 cases exhibited no changes.The causes of operative failure and diagnostic criteri on of lumbar disc herniaton and lumbar spinal stenosis are described in detail. The indications for re-operation were discussed.

Objective To compare the efficacy of operation and non-operatlon in treatment of cervical whiplash injuries. Methods A retrospective sturly was carried out in 88 cases of cervical whiplash injuries, of whom 24 cases were treated with non-operation and 64 with operation. There were 44 cases treated via anterior approach and 20 via posterior approach. NNeural function was evaluated by using Frankh classifications and ASIA (American Spinal Injury Association) grades. Results All cases were followed up for 6-24 months, which showed that neural function was improved significantly in both operation and non-operation groups. However, the neural function was better improved in the operation group compared with the non-operation, with statistical difference. The anterior approach group had significantly better outcome in neural function than the posterior approach group (P<0.05). Conclusion Operation is a better method and anterior approach should be the choice of treatment for treatment of cervical whiplash injuries.

BACKGROUND: Ossification of intervertebral disc, and ossification of spinal ligament and fibrous tissues are still uncertain.OBJECTIVE: To observe osteogenic potential of fibrous ring in the cervical intervertebral disc during bone fusion.DESIGN, TIME AND SETTING: The comparative observation was performed at the Experimental Animal Center of Second Military Medical University and Shanghai Institute of Orthopedics in October 2006.MATERIALS: Ten healthy goats, including 6 males and 4 females; titanium alloy cervical hollow threaded columnar internal fixator (CHTF) for goat, simulated human used internal fixator by Kanghui Medical Innovation Co., Ltd., Changzhou.METHODS: Every goat underwent conventional anterior cervical decompression and internal fixation. Two adjacent intervertebral spaces among C2-6 were selected and implanted with 2 CHTFs for each space. Of the 4 CHTFs, 3 were filled with cancellous bone alone, cancellous bone plus fibrous ring, and fibrous ring alone, respectively; the other one filled with nothing served as blank control.MAIN OUTCOME MEASURES: Implant location and fusion condition on anteroposterior and lateral radiographs and CT plain scanning at 6 and 12 weeks postoperatively; bone graft fusion and regional tissue reaction by histology.RESULTS: Radiographs and CT showed that CHTF was in the position during the whole experimental procedure with no loosening, displacement or dislocation. At 6 weeks, bone tissue was found surrounding CHTF and the vertebral body, and bone bridge formed in the connection site of CHTF and the vertebral body. New cartilage and bone trabecula formation were found in the CHTF filled with cancellous bone alone, accompanied by necrotic original bone graft; in the CHTF filled with cancellous bone and fibrous ring, necrotic fibrous tissue and newly formed cartilage accumulation surrounding original bone trabecula and fibrous ring were found; 6 weeks after surgery, there were fibrocartilage in fibrous tissue of CHTF filled with fibrous ring alone, and at 12 weeks postoperatively, newly formed cartilage was observed. In blank control group, only few newly formed cartilages were found at 12 weeks postoperatively. CONCLUSION: Enchondral ossification of fibroblast may be the osteogenic pattern of fibrous ring of cervical intervertebral disc.

Objective To summarize the clinical results of posterior fusion plus pedicle screw fixation in treatment of dens fracture combined with recoverable atlantoaxial dislocation. Methods Twenty-seven patients with dens fractures combined with recoverable atlantoaxial dislocation were treated with posterior pedicle screw fixation, reduction and fusion. In this series of patients, skull traction was made to restore the normal atlantoaxial joint before the operation. Results Atlantoaxial alignment or stability were restored, without complication due to instrumentation. A follow-up for 12-48 months (average 24 months) showed osseous union. Conclusion Posterior aflantoaxial pedicle screw and rod fixation provides immediate three-dimensional rigid fixation of aflantoaxial joint and is a more effective technique compared with previously reported techniques.

Objective Cervical hollow threaded fixator (CHTY) was designed and applied to stabilize tha cervical spine following anterior decompression due to cervical spondylosis or acute cervical disc herniation. Methods Medical use titanium alloy with no magnetism was made into a hollow threaded structure with holes on the wall of the fixator. Forly-two patients with cervical spondylosis and acute cervical disc herniation were stabilized using the CHTF technique after anterior decompression. X-ray films and CT scans were taken after the oberation to observe the stability ann fusion rate of the segments. Results Patients were allowed to walk one day after the operation and were followed up for 6 to 36 months. The operated segments were stable and solid fusion was observed 3-6 months after surgery. Conclusions Immediate stability of the operated segments can be obtained using the CHTF technique. Patients ware easy to manage after5 the operation and returned to their jobs in a short time.The CHTF technique is safe and simpa to perfoirme and eliminates the complications of an autograft.It may be an alternative to traditional cervical interbody fusion with bone graft.