Clinical outcomes after decompressive laminectomy for symptomatic ossification of ligamentum flavum at the thoracic spine.

Ossification of the ligamentum flavum (OLF) is a rare disease that causes acquired thoracic spinal canal stenosis and thoracic myelopathy. The aim of this study was to investigate clinical outcomes of symptomatic thoracic OLF treated using posterior decompressive laminectomy. We retrospectively analyzed the medical records of 22 patients who underwent posterior decompressive laminectomy for symptomatic thoracic OLF. The surgical results were evaluated using the modified Japanese Orthopaedic Association (JOA) scoring system and Hirabayashi recovery rate. The intensity of pain was evaluated using a visual analog scale (VAS). The mean duration of follow-up was 35.6months. The mean JOA score was significantly improved at final follow-up (9.18±standard deviation of 1.53 points [range, 6-11 points]) compared with before surgery (5.64±2.04 points [range, 3-9 points]) (P<0.001). The mean Hirabayashi recovery rate was 65.49% (range, 20-100%). Recovery outcomes were excellent in nine patients, good in eight patients, fair in four patients and unchanged in one patient. No patient was classified as deteriorated. The VAS scores were 2.82±3.08 before surgery and 0.59±1.05 at final follow-up (P=0.001). Surgical complications, which resolved after appropriate and prompt treatment, included dural tear in five patients, cerebrospinal fluid leakage in one patient, immediate postoperative neurologic deterioration in one patient, epidural hematoma in one patient, and wound infection in one patient. Our findings suggest that posterior decompressive laminectomy is an effective treatment for symptomatic thoracic OLF and provides satisfactory clinical improvement, but surgery for thoracic OLF is associated with a relatively high incidence of complications.

Esophageal perforation related to anterior cervical spinal surgery.

Esophageal perforation is an uncommon but potentially fatal complication of anterior cervical spinal surgery. This study aimed to investigate the diagnosis and treatment of cervical esophageal perforation related to spinal surgery. Among 1097 consecutive cases of anterior cervical spinal surgery that were managed at our institution over a 20 year period, five patients with esophageal perforation were identified. We performed a retrospective review of the diagnoses and treatment of esophageal perforation in these five patients as well as another patient who was transferred from another hospital. The esophageal perforations in all six patients were recognized during the early postoperative period. All patients presented with neck pain, dysphagia, odynophagia, coughing, fever and incision swelling and drainage. Diagnosis was confirmed by one or several of the following methods: contrast swallow study; endoscopy; cervical radiographs; or oral methylene blue. Nasogastric tube, intravenous antibiotics, enteral and parenteral nutrition, and open drainage were conducted in all patients. The wound was debrided in three patients, while two had implant removal and primary suture of the perforation. Five patients had a good recovery with healing of the esophagus, while one patient died due to severe pneumonia. The early diagnosis of esophageal perforation related to cervical spinal surgery relies on clinical suspicion and efficient investigation. The selection of appropriate treatment options, which include esophageal rest, antibiotic administration, nutrition support, wound debridement, open drainage, and surgical repair, largely depends on when the perforation is recognized. Early diagnosis and prompt management of this complication are likely to result in a good clinical outcome.

[Lithium chloride combined with human umbilical cord blood mesenchymal stem cell transplantation for treatment of spinal cord injury in rats].

OBJECTIVE: To observe the effects of lithium chloride combined with human umbilical cord blood mesenchymal stem cell (hUCB-SCs) transplantation in the treatment of spinal cord injury in rats. METHODS: Eighty female SD rats with complete T9 spinal cord transaction were randomized into 4 groups (n=20), namely the control group (group A), lithium chloride group (group B), hUCB-SCs group (group C) and hUCB-SCs(+) lithium chloride group (group D). On days 1 and 3 and the last days of the following weeks postoperatively, the motor function of the hindlimb of the rats were evaluated according to the BBB scores. At 8 weeks, all the rats were sacrificed and the spinal cords were taken for morphological observation. The spinal cord tissues at the injury site were observed with Brdu nuclear labeling to identify the survival and migration of the transplanted SCs. The regeneration and distribution of the spinal nerve fibers were observed with fluorescent-gold (FG) spinal cord retrograde tracing. RESULTS: Brdu labeling showed that the transplanted hUCB-SCs survived and migrated in the spinal cord 8 weeks postoperatively in groups C and D. FG retrograde tracing identified a small amount of pyramidal cells that migrated across the injury site in groups C and D. The BBB scores of the hindlimb motor function 8 weeks postoperatively were 4.11∓0.14, 4.50∓0.15, 8.31∓0.11 and 11.15∓0.18 in groups A, B, C and D, respectively. CONCLUSION: Lithium chloride can promote the survival and differentiation of hUCB-SCs into neural cells at the injury site. Lithium chloride combined with hUCB-SCs transplantation may accelerate functional recovery of the hindlimbs in rats with complete transection of the spinal cord.

[The repair of acute spinal cord injury in rats by olfactory ensheathing cells graft modified by glia cell line-derived neurotrophic factor gene in combination with the injection of monoclonal antibody IN-1].

OBJECTIVE: To research the repair effect of transplantation of glial cell line-derived neurotrophic factor (GDNF) modified olfactory ensheathing cells (OECs) combination with injecting axonal growth inhibiting protein antibody (IN-1) in vivo. METHODS: To construct lentivirus vector with GDNF gene and infect OECs in vitro, use the immunoblotting (Western Blot) to observe the expression of GDNF was detected through Western Blot. Fifty adult female SD rats which to establish thoracic spinal cord transection injury model were randomly divided into A (control group), B (IN-1 antibody group), C (OECs group), D (GDNF-OECs group), and E (GDNF-OECs+IN-1 group) 5 groups of each 10 rats. To observe regeneration of the impaired nerve axon by NF200 immunohistochemistry, Biotinylated dextran amine (BDA) anterograde tracing corticospinal tract. Basso, Beattie and Bresnahan (BBB) score was used to evaluating hindlimb motor function recovery. RESULTS: Add up to 13 rats died post operation. OECs labeled by hoechst still survived and migrated in spinal cord 8 weeks post operation. Lots of confused and disorderly regenerated axons which crossing the injured region of spinal cord were displayed between spinal cord stumps in GDNF-OECs+IN-1 group and GDNF-OECs group; some of axons existed in OECs group, but there is no obviously continue nerve fibers crossing the injured region of spinal cord;in contrast to IN-1 and control groups, few of regenerated axons and atrophy of spinal cord stumps were observed. The results of BBB hindlimb motor rating scale were 7.70+/-0.24, 7.89+/-0.15, 10.50+/-0.25, 11.43+/-0.23 and 12.81+/-0.40 for the control group, IN-1 group, OECs group, GDNF-OECs group and the allied treatment group respectively. CONCLUSIONS: The transplantation of GDNF-OECs combination with IN-1 antibody may benefit the survival and regeneration of the injured axons, and accelerate the repair of the injured spinal cord and functional recover of hindlimb locomotor in rats in a more efficient way than that with OECs or IN-1 alone.

[Effects of mechanical vibration on the morphology of the acellular scaffold for the spinal cord].

OBJECTIVE: To investigate the effects of mechanical vibration on the morphology of the acellular scaffold for the spinal cord and establish a procedure to construct an acellular rat spinal cord allograft retaining intact matrix fibers for repairing spinal cord injuries. METHODS: Fifteen segments of rat spinal cord were divided randomly into 3 groups and subjected to mechanical vibration at the frequency 80 r/min (group A, n=5), 120 r/min (group B, n=5), and 160 r/min (group C, n=5) respectively. The spinal cord was treated with Triton X-100 and sodium deoxycholate at room temperature and washed with distilled water. The specimens were observed microscopically with HE staining, and the ultrastructure was observed using scanning electron microscope. RESULTS: In group A, the spinal cord specimens contained numerous cells and neural sheaths. Vibration at 120 and 160 r/min (in groups B and C) resulted in depletion of all the cells, axons and neural sheaths from the spinal cord after treatment with Triton X-100 and sodium deoxycholate. The acellular spinal cord consisted of a meshwork of the matrix fibers in longitudinal arrangement. In group C, however, obvious disruption of both the spinal dura mater and the matrix fiber occurred in the acellular spinal cord. CONCLUSION: All the cells, axons and neural sheaths in the spinal cord can be removed by chemical extraction with Triton X-100 and sodium deoxycholate. Mechanical vibration at suitable frequency may cell preserve the 3-dimensional structure of the matrix fibers. The acellular spinal cord scaffold may serve as an ideal material for constructing tissue-engineered spinal cord.

[Risk factors of secondary kyphotic angle increment after veterbroplasty for osteoporotic vertebral body compression fractures].

OBJECTIVE: To study the risk factors of secondary kyphotic angle increment after bone cement vertebroplasty for osteoporotic vertebral compression fractures. METHODS: From October 2005 to May 2006, 32 (45 vertebrae) bone cement vertebroplasty procedures were performed. The operation time, injected cement volume, bone mineral density, visual analog scale (VAS) pain score, vertebral height, and kyphotic angle were recorded. The secondary increment of the kyphotic angle was calculated, and correlation analysis and linear regression analysis were performed. RESULTS: The bone mineral density, the postoperative kyphotic angle and the vertebral midline height were significantly correlated to the secondary increment of the kyphotic angle. CONCLUSION: Large postoperative kyphotic angle, poor postoperative recovery of the vertebral midline height, and low bone mineral density are all risk factors of secondary increment of the kyphotic angle.

[Analysis of the long-term outcome of anterior approach surgery on cervical spondylotic myelopathy].

OBJECTIVE: To investigate the long-term efficacy of anterior approach surgery on cervical spondylotic myelopathy and factors affecting prognosis. METHODS: The data in 116 patients suffered from cervical spondylosis from January 1992 to December 2000 were reviewed, including 80 male cases and 36 female cases, whose age ranged from 36 to 76 years (mean, 51 years). The preoperative course of disease was 2 months to 20 years (mean, 19 months). There were 65 cases (56.0%) with single segments involved, 44 cases (37.9%) with two segments, 7 cases (6.0%) with three segments. Ninety-eight cases were onset slowly, 18 cases with no remote cause and aggravating quickly. Three kinds of surgeries were performed: anterior cervical decompression and autoiliac bone interbody fusion, anterior cervical decompression and fusion with threaded fusion cage, anterior cervical decompression and autoiliac bone interbody fusion with anterior screw-plate system. Improvement in spinal cord function was assessed using the Japanese Orthopaedic Association (JOA) scoring system, the long-term efficacy and influential factors were also analyzed. RESULTS: The mean follow-up time was 7 years and three months (5 - 12 years). The mean preoperative JOA score was 9.34 +/- 1.81. The mean postoperative JOA score was 10.35 +/- 1.85. At the final follow-up, the JOA score was 14.09 +/- 1.90 and the recovery rate was 63.2%. Among the total patients, 27 cases were excellent, 47 cases were fine, 23 cases were good, 19 cases were poor, the fineness rate was 63.8%. The long-term efficacy of anterior approach surgery has close correlations with time of course, age of onset, preoperative spinal cord function and the number of affected segments, but has no correlations with modes of fusion and internal fixation. CONCLUSIONS: The patients will be attentively observed while having a definite diagnosis of cervical spondylotic myelopathy. The good long-term results will be obtained after early anterior cervical decompression and fusion.

Protective effect of liposome-mediated glial cell line-derived neurotrophic factor gene transfer in vivo on motoneurons following spinal cord injury in rats.

OBJECTIVE: To investigate the effect of liposome-mediated glial cell line-derived neurotrophic factor (GDNF) gene transfer in vivo on spinal cord motoneurons after spinal cord injury (SCI) in adult rats. METHODS: Sixty male Sprague-Dawley rats were divided equally into two groups: GDNF group and control group. The SCI model was established according to the method of Nystrom, and then the DC-Chol liposomes and recombinant plasmid pEGFP-GDNF cDNA complexes were injected into the injured spinal cord. The expression of GDNF cDNA 1 week after injection was detected by RT-PCR and fluorescence microscope. We observed the remaining motoneurons in the anterior horn and the changes of cholinesterase (CHE) and acid phosphatase (ACP) activity using Nissl and enzyme histochemistry staining. The locomotion function of hind limbs of rats was evaluated using inclined plane test and BBB locomotor scale. RESULTS: RT-PCR and fluorescence observation confirmed the presence of expression of GDNF cDNA 1 week and 4 weeks after injection. At 1, 2, 4 weeks after SCI, the number of motoneurons in the anterior horn in GDNF group (20.4+/-3.2, 21.7+/-3.6, 22.5+/-3.4) was more than that in control group (16.8+/-2.8, 17.3+/-2.7, 18.2+/-3.2, P<0.05). At 1, 2 weeks after SCI, the mean gray of the CHE-stained spinal motoneurons in GDNF group (74.2+/-25.8, 98.7+/-31.6) was less than that in control group (98.5+/-32.2, 134.6+/-45.2, P<0.01), and the mean gray of ACP in GDNF group (84.5+/-32.6, 79.5+/-28.4) was more than that in control group (61.2+/-24.9, 52.6+/-19.9, P<0.01). The locomotion functional scales in GDNF group were higher than that in control group within 1 to 4 weeks after SCI (P<0.05). CONCLUSIONS: GDNF gene transfer in vivo can protect motoneurons from death and degeneration induced by incomplete spinal cord injury as well as enhance locomotion functional restoration of hind limbs. These results suggest that liposome-mediated delivery of GDNF cDNA might be a practical method for treating traumatic spinal cord injury.

[The selection of the surgical approach in the management of fracture and dislocation of lower cervical spine combined spinal cord injury].

OBJECTIVE: To investigate how to select an appropriate surgical approach in the management of fracture and dislocation of lower cervical spine combined spinal cord injury. METHODS: The clinical data of 54 patients of lower cervical spine fracture and dislocation were retrospectively analyzed. There were 29 cases with vertebral body compressive fracture and dislocation, 7 cases with vertebral body bursting fracture and dislocation, 3 cases with unilateral facet dislocation, 15 cases with bilateral facet dislocation. All cases were associated with spinal cord injury. According to American Spinal Injury Association (ASIA) grades, 21 cases were in A grade, 5 cases in B grade, 22 cases in C grade and 6 cases in D grade. All patients had surgical reduction, decompression, stabilization and fusion, 43 cases in anterior approach and 11 cases in posterior approach. RESULTS: All patients were followed up in 12 to 36 months, the mean follow-up time was 18 months. There were no great vessels, trachea, esophagus or spinal cord iatrogenic injury. There were no pull-out and breakage of screws or plates. Fusion was achieved in all patients at an average of 12 weeks postoperatively. There were no pseudarthrosis or bone nonunion. Of all the patients, 96.3% were acquired completely reduction and the normal intervertebral height and lordosis were maintained. Patients with complete spinal cord had no neurologic recovery, but they felt relief from upper limb pain or numb. Incomplete spinal cord lesions improved on average 1-2 Frankel grade after surgery. CONCLUSIONS: For lower cervical spine fracture and dislocation, an ideal anatomy reduction can be obtained with either anterior or posterior approach surgery. It is important to select a suitable surgical approach according to different types of cervical fracture and dislocation.

Cationic liposome-mediated GDNF gene transfer after spinal cord injury.

Glial cell line-derived neurotrophic factor (GDNF) has been shown to protect cranial and spinal motoneurons, which suggests potential uses of GDNF in the treatment of spinal cord injury (SCI) and motor neuron disease. We examined neuroprotective effect of cationic liposome-mediated GDNF gene transfer in vivo on axonal regeneration and locomotor function recovery after SCI in adult rats. The mixture of DC-Chol liposomes and recombinant plasmid pEGFP-GDNF cDNA was injected after SCI. RT-PCR confirmed the increased expression of GDNF mRNA in the injected areas at 7 days after injection. The expression of EGFP-GDNF was observed in the cells around the injection locus by fluorescence microscope at least 4 weeks after injection. Four weeks after GDNF gene transfer, regeneration of the corticospinal tracts was assessed using anterograde tract tracing. There are more HRP labeling of corticospinal tract axons across the lesion in GDNF group compared with control group. In GDNF group, the maximum distance these labeled axons extended varied in different animals and ranged from 5 mm to approximately 9 mm from the lesion. In control group, no HRP labeled axons extended caudal to the lesion. The locomotion function of hindlimbs of rats was evaluated using inclined plane test and BBB locomotor scores. The locomotion functional scores in GDNF group were higher than that in control group within 1-4 weeks after SCI (p < 0.05). These data demonstrate that in vivo transfer of GDNF cDNA can promote axonal regeneration and enhance locomotion functional recovery, suggesting that cationic liposome-mediated delivery of GDNF cDNA may be a practical gene transfer method for traumatic SCI treatment.