A Study On Damage Control Orthopedics For Spinal Cord Injury

Objective Establish the spinal cord compression injury animal models by percutaneous transluminal coronary angioplasty(PTCA)balloons dilatation catheter with New Zealand white rabbits to simulate the spinal cord compression injury(SCI)by thoracolumbar burst fracture.Then to investigate the operation procedures and effects of Damage Control Orthopedics(DCO)for spinal cord compression injury.Methods Spinal cord compression injury model was introduced in 45 clean and healthy male New Zealand white rabbits.Establish the SCI animal models by percutaneous transluminal coronary angioplasty(PTCA)balloons dilatation catheter.Decompression begins 2 days later after the first operation.5 rabbits were randomly selected from the 45 models to carry on the researches of behavioral science,apoptotic spinal cord cells detected by flow cytometry(FCM),histopathological and immunohistochemical staining method to detect expression of matrix metalloproteinase-2(MMP-2)in rabbits an hour before decompression(control group).The remaining 40 rabbits were randomly divided into 2 groups,20 cases in each group.The total laminectomy began far from the heavy oppressed side of the spinal cord after the pressure reduced to half in the balloon in the first group(DCO operation group,group A).While the second group resect the whole vertebral plate from the heavy oppressed side(traditional operation group,group B).Take out the balloon after decompression in the 2 groups.5 rabbits were randomly and respectively taken from the 2 groups at the 1d,3d,7d,14 d after decompression to complete the above test contents.Results The differences of improved Tarlov motor function grades were not statistically significant between control group and group A and B at 1d after decompression(P>0.05).The differences of improved Tarlov motor function grades were not statistically significant between group A and B at 1d,3d,7d post-decompression(P>0.05).The improved Tarlov motor function grade test in the group A was significantly improved compared with that in the group B at 14 d after decompression(P<0.05).No significant differences with respect to the apoptosis between group A and B(P>0.05)at 1d,3d after decompression.The apoptosis was lower in group A and B at 1d post-decompression than control group(P<0.05).The differences of the apoptosis were not statistically significant between 1d and 3d post-decompression and between 7d and 14 d post-decompression in group A(P>0.05)and the same as to the group B(P>0.05).However,the apoptosis was higher at 7d than at 3d post-decompression in group A(P<0.05)and the same as to group B(P<0.05).In addition,the apoptosis was lower in group A than group B at 7d and 14 d after decompression(P<0.05).HE staining in control group showed mild demyelination changes and vacuolar degeneration in white matter company with nerve cell edema and neuron atrophy in gray matter.The injury of spinal cord in 1d,3d,7d and 14 d after decompression in group A and B showed the nerve cell edema company with degeneration in gray matter until pathological changes deteriorated at 7d after decompression,and maintain the changes to 14 d after decompression,The diffuse demyelination changes company with dotted hemorrhage was showed in white matter.The immunohistochemical staining method to detect expression of MMP-2 in rabbits showed that the expression of MMP-2 in group B were significantly higher than group A(P<0.05).The expression of MMP-2 were lower in the group A and B at 1d post-decompression than in the contol group(P<0.05).The expression of MMP-2were higher at 3d than 7d post-decompression and the expression were higher at 7d than 14 d post-decompression in group A and the same as to group B(P<0.05).However,no significant differences with respect to the the expression of MMP-2 between 1d and 3d post-decompression in group A(P>0.05)and the same as to group B(P>0.05).Conclusion The operation of traditional decompression was decompressed from the heavy oppressed side of spinal cord without increasing the effective volume of the spinal canal,Which was easy to cause the spinal cord second injury.The DCO was more effective than the second operation in who suffer thoracolumbar burst fracture that caused spinal cord injury and oppression.