To compare the effectiveness of the operations in treatment of thoracolumber spine fracture and dislocation with spinal cord injury in different periods. Methods Between June 2003 and June 2008, 80 cases of thoracolumber spine fracture and dislocation with spinal cord injury were treated. There were 52 males and 28 females with an average age of 37.6 years (range, 28-49 years). According to different operative time, they were divided into 2 groups by randomized controlled study: group A (n=39, operation was performed within 24 hours) and group B (n=41, operation was performed at 3-7 days). In group A, there were 23 cases of degree I-II (group A1), 16 cases of degree III-V (group A2) according to Meyerding standard, including 17 cases of grade A, 7 cases of grade B, 9 cases of grade C, and 6 cases of grade D according to Frankel scoring system. In group B, there were 21 cases of degree I-II (group B1) and 20 cases of degree III-V (group B2), including 20 cases of grade A, 7 cases of grade B, 11 cases of grade C, and 3 cases of grade D. All cases were treated with posterior spinal cord decompression and reduction, with internal fixation by pedicle screw-rod system and transforamen lumbar interbody fusion. Results The blood loss was (407.4 ± 24.3) mL in group A1 and (397.4 ± 8.2) mL in group B1, showing no significant difference (t=1.804, P=0.078); the blood loss was (1 046.9 ± 128.6) mL in group A2 and (494.4 ± 97.7) mL in group B2, showing significant difference (t=14.660, P=0.000). All 80 patients were followed up 2 years to 2 years and 6 months (mean, 2 years and 3 months) with satisfactory results in spinal cord decompression and reduction, and bony fusion was achieved at 12 months. There was no significant difference in the vertebral canal volume, vertebral height, and Cobb angle at both pre- and postoperation between 2 groups (P gt; 0.05). No loosening or breakage of screws and rods occurred. At 12 months after operation, the cure rates were 47.83% (11/23) in group A1 and 19.05% (4/21) in group B1, showing significant difference (χ2=4.046, P=0.044); the cure rates were 12.50% (2/16) in group A2 and 10.00% (2/20) in group B2, showing no significant difference (χ2=0.056, P=0.813). There was no significant difference (χ2=0.024, P=0.878) in the cure rates in the patients at grades A and B before operation between group A (12.50%, 3/24) and group B (11.11%, 3/27); but there was significant difference (χ2=5.992, P=0.014) in the cure rates in the patients at grades C and D before operation between group A (66.67%, 10/15) and group B (21.43%, 3/14). Conclusion Emergency operation of posterior pedicle screw-rod system for treatment of thoracolumber spine fracture and dislocation with spinal cord injury can provide good reduction, rigid fixation, and high fusion rate, so it is asafe and effective treatment method.
Objective To explore the failure cause of posterior approach orthopaedic operation of thoracolumbar hemivertebra, and to summary strategies of revision. Methods The cl inical data from 9 cases undergoing posterior approach orthopaedic operation failure of thoracolumbar hemivertebra between June 2003 and June 2008, were retrospectively analyzed. There were 5 males and 4 females with a median age of 12 years (range, 1 year and 10 months to 24 years). All malformations were identified as fully segmented hemivertebra from the original medical records and X-ray films, including 2 cases in thoracic vertebra, 5 cases in thoracolumbar vertebra, and 2 cases in lumbar vertebra. The preoperative scol iotic Cobb angle was (45.4 ± 17.4)°, and kyphotic Cobb angle was (29.8 ± 22.0)°. The reason of primary surgical failure were analyzed and spinal deformity was corrected again with posterior revision. Results All surgeries were finished successfully. The operation time was 3.0-6.5 hours (mean, 4.5 hours), and the perioperative bleeding was 400-2 500 mL (mean, 950 mL). All incisions healed by first intention; no infection or deep venous thrombosis occurred. Numbness occurred in unilateral lower extremity of 1 case postoperatively, and the symptom was rel ieved completely after treatment of detumescence and neural nutrition. All cases were followed up 12-30 months (mean, 18 months). No pseudoarthrosis and implant failure occurred. The X-ray films showed that the bone grafts completely fused within 8-14 months (mean, 11 months) after operation. The Cobb angles of scol iosis and kyphosis at 1 week after operation and the last follow-up were obviously improved when compared with preoperative ones, showing significant differences (P lt; 0.05). No obvious correction loss was observed either in coronal or sagittal plane. Conclusion The failure causes of posterior approach orthopaedic operation are hemivertebra processing, selection of fixation and fusion range, and selection of internal fixation. If the strategies of revision are made after the above-mentioned failure causes are considered, the cl inical results will be satisfactory.
Objective To make a mouse model of traumatic spinal cord injury (SCI) by Allen’s weight dropping (WD),which might be helpful for further research on the mechanism of SCI. Methods A total of 180 healthy female mice, weighing 17 - 23 g (20 g on average), were randomized into 4 groups (n=45 per group): the experimental groups of A, B and C and the control group of D. Experimental groups were distinguished by the amount of weight or the height from which the weight was dropped onto an impounder resting on the dura (2.0 × 2.5 g·cm, 2.5 × 3.0 g·cm, 3.0 × 5.0 g·cm). In group D, neural scute was opened only and spinal cord was exposed without SCI. The recovery of the lower extremity was observed at various time points (0,6 and 12 hours, 1 and 3 days, 1, 2, 4 and 8 weeks) by using the Basso mouse scale (BMS) scoring system, motor evoked potentials (MEP) and histological observation. Results MEP displayed that the incubation period of N1 wave was extended in group B after 6 hours and in group C after 12 hours. As time passed by, the incubation periods of N1 wave in group A, group B and group C began to shorten. The incubation period in group A was close to normal at 4 weeks (2.40 ± 0.12) ms, and there was no significant difference compared with group D (P gt; 0.05). The incubation period in group B was close to normal at 8 weeks (2.96 ± 0.15) ms, and there was no significant difference compared with group D (P gt; 0.05). The incubation period in group C was still relatively high at 8 weeks (3.76 ± 0.13) ms, and there was a significant difference compared with group D (P﹤0.05). Both hind l imbs of all mice were paralytic instantly after SCI, the score of main BMS was 0 point; the score of main BMS was close to 0 at the first 3 days after SCI, the score of main BMS of group A was 8.00 ± 0.13 and group B was 7.50 ± 0.31 at 8 weeks;the score of main BMS of group A was 5.45 ± 0.12 at 1 week and group B was 5.45 ± 0.15 at 2 weeks which were significant difference compared with group D (P﹤0.05).There were significant differences among groups A, B and C after 1 week of SCI (P lt; 0.05), and group C was lower than the others(P﹤0.01). The score of adjuvant BMS of group A was 10.12 ± 0.76 at 2 weeks and group B was 9.85 ± 0.55 at 8 weeks which was no significant difference compared with the group D at the same time (P gt; 0.05). Histological observation showed hemorrhage, cellular edema, inflammatory cell infiltration, nerve cell swell and solution of Nissl body 12 hours after SCI in group C. As time passed by, the number of nerve cells decreased, the gl ial cell prol iferated and Nissl body vanished. There was much gl ial cell prol iferation and cavitation 2 weeks after SCI in group C. The nerve cell decrease and cavitation in group B was sl ighter than that in group C, and group A was the sl ightest. In group D, there was no obvious change of the number of cells during the observation apart from sl ight edema in early period. Conclusion The mouse model precisely reflects the pathological and physiological features and law of change after different degrees of SCI, and can be used as a standard of mouse model of traumatic SCI by Allen’s WD.
Objective Titania and Ag containing nano-hydroxyapatite/polyamide 66 (TiO2-Ag-nHA/PA66) composite bone fill ing material has good biocompatibil ity and biological safety. To investigate the antibacterial effect and Ag+ release characteristics of TiO2-Ag-nHA/PA66 composite bone fill ing material containing different concentrations of Ag+ in vitro. Methods The n-HA/PA66 composite bone fill ing material A1 (material A1) was prepared by co-polymerization method, and TiO2-Ag-nHA/PA66 composite bone fill ing materials A2 and A3 (materials A2 and A3) were prepared by thesame way containing Ag+ of 0.22wt% and 0.64wt%, respectively, and the TiO2 content was 2.35wt%. The materials A2 and A3 were respectively immersed in 50 mL simulated body fluid (SBF), and Ag+ concentration was measured by atomic absorption spectrometry at 1, 3, 7, 14, 21, and 49 days. The inhibition ring test and colony count method were used to evaluate antibiotic effect against Staphylococcus aureus and Escherichia coli, the anti-adhesion capacity of Staphylococcus aureus and Escherichia coli was observed by scanning electron microscope (SEM). Results There was no significant difference in the Ag+ concentration between materials A2 and A3 at 1 day and 3 days (P gt; 0.05); and there were significant differences in the Ag+ concentration between materials A2 and A3 after 7 days (P lt; 0.05). The inhibition ring diameters of materials A2 and A3 to Staphylococcus aureus and Escherichia coli reached the maximum at 1 day, which were (13.40 ± 2.88), (9.40 ± 1.14) mm and (23.60 ± 1.14), (18.80 ± 0.84) mm, showing significant difference (P lt; 0.05) between materials A2 and A3 respectively; and then, the diameter of inhibition ring reduced with the time. The antibacterial effect of materials A2 and A3 against Staphylococcus aureus and Escherichia coli lasted 15, 33 days and 9, 24 days, respectively. No inhibition ring was observed around material A1 all the time. And the inhibitory rates of materials A2 and A3 were 89.74% ± 3.62%, 94.18% ± 2.05% and 78.65% ± 5.64%, 85.96% ± 2.50%; showing significant differences (P lt; 0.05) among materials A1, A2, and A3. SEM showed that bacterial adhesion of materials A2 and A3 was obviously fewer than that of material A1. Conclusion TiO2-Ag-nHA/PA66 composite bone fill ing material has antibacterial property against Staphylococcus aureus and Escherichia coli, and it has a good release effect in SBF.