The Influence Of Early Stage After PKP Treatment On Spino-pelvic Sagittal Balance In Patients With OVCF

BackgroundThe spino-pelvic sagittal balance has attracted wide attention from scholars in recent years.A variety of spinal diseases(spinal deformity,intervertebral disc degenerative disease,spondylolisthesis,etc.)can cause sagittal imbalance,resulting in obvious symptoms and affecting the quality of life of patients.Sagittal balance status has been demonstrated to be an independent predictor of clinical status and outcomes in these patients[1-4].Studies have shown that the surgical correction of sagittal imbalance has correlated with clinical improvement[5].At present,the research on sagittal imbalance caused by spinal deformity,spondylolisthesis and degenerative disc disease was more extensive.But little attention has been paid to the sagittal imbalance caused by osteoporotic vertebral compression fracture.The incidence of osteoporotic vertebral compression fracture(OVCF)is higher in the elderly.After the occurrence of osteoporotic vertebral compression fracture,it is often accompanied by the compression of the anterior column of the vertebral body and the loss of the anterior height of the vertebral body,which can cause kyphosis of the spine and even sagittal imbalance[6].The influence of osteoporotic vertebral compression fracture on spino-pelvic sagittal balance has not been systematically studied.Sagittal imbalance caused by scoliosis or spinal deformity often needs to be corrected by osteotomy.However,OVCF often occurs in the elderly,whose general condition is poor and the tolerance rate of open surgery is low.And most of the elderly patients were complicated with osteoporosis,the screw holding force was weak and the failure rate was high after spinal internal fixation.It is well known that percutaneous kyphoplasty(PKP)is a common minimally invasive treatment for osteoporotic vertebral compression fractures.However,whether PKP can improve the spino-pelvic sagittal balance in patients with osteoporotic vertebral compression fracture,thus avoiding many disadvantages of osteotomy,is still controversial[9-11].In clinical work,we found that some patients with osteoporotic vertebral compression fracture had symptoms of sagittal imbalance before the operation,and the sagittal imbalance was significantly improved after the minimally invasive treatment of PKP.Therefore,we conclude that PKP plays a role in improving the sagittal plane of patients with osteoporotic vertebral compression fractures.In order to solve these problems,we conducted a retrospective study to explore the changes of sagittal balance parameters in patients with osteoporotic vertebral compression fracture,and to reveal whether the classic minimally invasive treatment of PKP can improve the spino-pelvic sagittal balance and its regularity,so as to provide a theoretical basis for the selection of surgical methods for the same type of patients in the future.This study is divided into the following three parts:English Abstracts(part I)ObjectiveTo analyze the changes of spino-pelvic sagittal balance parameters and the correlation between OVCF and sagittal balance parameters after osteoporotic vertebral compression fracture.To analyze the changes of spino-pelvic sagittal balance in patients with osteoporotic vertebral compression fracture before and after PKP operation,and to determine whether PKP can improve the spino-pelvic sagittal balance.MethodsA retrospective study was conducted on 120 patients with OVCF who received PKP treatment.At the same time,26 healthy elderly volunteers(over 59 years old)were selected as the control group.The sagittal parameters were measured according to the whole spine X-ray film of standing position before and after PKP,and compared with healthy elderly volunteers to find the change rule of sagittal parameters.The differences of sagittal parameters between the PKP treatment group and the control group,as well as the changes of sagittal parameters before and after PKP in the treatment group,were statistically analyzed.ResultsCompared with healthy volunteers,all parameters except PI and LL in the OVCF group were significantly different from those in the control group.TK,TLK,PT,SVA and TPA were significantly higher than those in the control group,while SS and SSA were significantly lower than those in the control group.All local spinal sagittal parameters were significantly improved after PKP treatment,and the difference was statistically significant.In pelvic parameters,PT decreased,SS increased,and compensatory pelvic posterior rotation decreased.The global sagittal angle parameters(TPA and SSA)were also significantly improved,and the difference was statistically significant.Correlation between spino-pelvic sagittal parameters:1.Pelvic parameters:there was a significant correlation among pelvic sagittal parameters PI,PT and SS in both normal control group and OVCF group.2.Spinal parameters:there was a significant correlation between TK and LL.In the OVCF group,there was also a significant correlation among the local sagittal plane parameters TK,TLK and Cobb,which reflected the kyphosis of the thoracolumbar segment.3.Correlation between spinal parameters and pelvic parameters:both groups of data analysis found that LL was positively correlated with PI-LL and negatively correlated with SS.4.Global sagittal parameters:SSA was positively correlated with SS and negatively correlated with LL.TPA was positively correlated with PT and PI-LL.There is a negative correlation between SSA and TPA.There was no significant correlation between SVA and most spinal and pelvic parameters.Conclusion1.After the occurrence of an osteoporotic vertebral compression fracture in elderly patients,the spino-pelvic parameters of sagittal balance changed significantly.The main manifestation of the spine is the enlarged angle of thoracolumbar kyphosis,but the change of lumbar lordosis is not obvious.In order to reduce the forward movement of the body gravity line caused by thoracolumbar kyphosis,there is a modern compensatory posterior rotation of the pelvis.Even if the pelvic posterior rotation alleviates the forward movement of the body gravity line caused by osteoporotic vertebral compression fracture,the global sagittal parameters still change significantly,and even cause sagittal imbalance.2.PKP is an effective method for the treatment of OVCF patients with abnormal spino-pelvic sagittal balance.After PKP,the global sagittal balance is improved mainly by reducing kyphosis and relieving pelvic posterior rotation.3.There was a wide correlation between spinal and pelvic parameters in both the normal control group and the OVCF group.In the global sagittal balance parameters,SSA is affected by both pelvic and spinal parameters,while TPA is mainly affected by pelvic parameters.There is no significant correlation between SVA and most spinal and pelvic parametersEnglish Abstracts(part II)ObjectiveAnalyze the effect of osteoporotic vertebral compression fracture at different fracture sites on the sagittal balance.At the same time,the changes of spino-pelvic sagittal balance in patients with OVCF before and after PKP were analyzed to determine whether the improvement of spino-pelvic sagittal balance after PKP was affected by the location of vertebral fracture.Methods90 patients with OVCF who received PKP were studied retrospectively.According to the location of the fractured vertebrae,all patients were divided into three groups:upper thoracic vertebra group(MT group)(T1 to T9),thoracolumbar group(TL group)(T10 to L2)and lower lumbar vertebra group(LU group)(L3 to L5).At the same time,26 healthy elderly volunteers(over 59 years old)were selected as the control group.The sagittal parameters were measured on the X-ray of the whole spine before and after operation.The differences of sagittal parameters between each group and the control group,and the differences of sagittal parameters between groups before and after operation were statistically analyzed.The differences of sagittal parameters between the PKP treatment group and the control group and the changes of sagittal parameters before and after operation in the treatment group were statistically analyzed.ResultsAfter the occurrence of OVCF,there were significant differences in almost all parameters except PI and LL between the TL group and the control group.There was only a significant difference in local sagittal plane parameters(TK,TLK,LL)in the MT group.There was no significant difference in almost all parameters except PT and TPA in the LU group.After PKP treatment,most of the sagittal parameters in the TL group were significantly improved,except TK and SVA.Only TLK decreased significantly in the MT group,while only local kyphosis Cobb angle and SSA improved in the LU group.Conclusion1.When osteoporotic vertebral compression fracture occurs in the upper thoracic vertebra,the body corrects the changes of thoracic kyphosis caused by the fracture only through the compensatory increase of lumbar lordosis,without initiating the mechanism of pelvic compensation.It has no significant effect on the global sagittal balance.2.OVCF of the lower lumbar spine was more likely to occur in patients with larger PI angle.After the occurrence of fracture,compensatory sagittal balance can be achieved through pelvic retroversion,and sagittal imbalance is rare.3.Compared with the upper thoracic vertebrae and the lower lumbar vertebrae,the osteoporotic vertebral compression fractures in the thoracolumbar segment have the greatest influence on the spino-pelvic sagittal parameters and global sagittal parameters,so it is more likely to cause sagittal imbalance.However,among the three groups,the sagittal parameters of patients in the thoracolumbar group improved best after PKP surgery.English Abstracts(part ?)ObjectiveTo analyze whether the effect of osteoporotic vertebral compression fracture on spino-pelvic sagittal parameters is different due to the number of fractured vertebrae.And analyze whether the improvement of sagittal balance after PKP treatment is different according to the number of fractured vertebrae.Methods99 patients with thoracolumbar OVCF who underwent PKP were studied retrospectively.According to the number of vertebral bodies of fracture,all cases were divided into three groups:single vertebral body fracture group(Single VCF group),double vertebral body fracture group(Double VCF group)and multiple vertebral body fracture group(Multiple VCF group,the number of vertebral bodies was more than or equal to 3).The control group consisted of 26 healthy elderly volunteers.The X-ray films of the whole spine in standing position were examined before and after operation,and the sagittal parameters were measured.The differences of sagittal parameters between each group and the control group,and the improvement of sagittal parameters before and after PKP in each operation group were statistically analyzed.ResultsCompared with the control group,TK and TLK increased significantly,PT increased and SS decreased after fracture in the three groups,indicating the kyphosis of the thoracolumbar segment and the tendency of body tilting forward after fracture.In order to avoid sagittal imbalance,the body was compensated by pelvic posterior rotation.Compared with the normal group,SSA decreased,TPA increased,and the global sagittal balance changed significantly due to vertebral fracture.Before the PKP treatment,there was no significant difference in sagittal parameters among the operation groups.The VAS score of the third group was relatively higher,and there was a significant statistical difference.After PKP,the local sagittal Cobb angle decreased significantly in three groups,TLK decreased,LL increased,thoracolumbar kyphosis improved and lumbar lordosis increased in the Single VCF group and Double VCF group.In terms of pelvic parameters,there was a significant decrease in PT and an increase in SS in the Single VCF group,and the pelvic compensatory posterior rotation was relieved after PKP.Global sagittal parameters:there were significant differences in SSA increase and TPA decrease in the Single VCF group.In the Double VCF group,only TPA decreased,and the change of SSA was not statistically significant.There was no significant improvement in sagittal parameters in the Multiple VCF group,and there was no significant improvement in sagittal balance after PKP treatment in the Multiple VCF group.Conclusion1.There is no significant difference in the effect of the number of vertebral fracture segments on the sagittal balance of patients with osteoporotic thoracolumbar vertebral compression fracture,but the improving effect of PKP on sagittal balance is significantly related to the number of vertebral fracture segments.2.Osteoporotic thoracolumbar vertebral compression fracture of single vertebrae has the best improvement of sagittal balance after PKP.With the increase of the number of fractured vertebrae,the effect of PKP on the improvement of sagittal balance gradually weakened.The more fractured vertebrae,the worse the improvement effect of PKP on sagittal balance.