Analysis Of Related Factors Of Injured Vertebral Body Recompression After PKP Treatment Of Osteoporotic Vertebral Compression Fracture

Object:To explore the factors related with percutaneous kyphoplasty(PKP)in the treatment of osteoporotic vertebral compression fracture(OVCF).Methods:From September 2016 to August 2018,a study was conducted on single segment OVCF patients who were treated with PKP in the same medical group of our hospital.Visual analogue score(VAS score)and Oswestry dysfunction index(ODI index)were used to reflect the degree of pain,and vertebral compression ratio and Cobb angle were used to reflect the degree of vertebral compression.VAS score,ODI index,vertebral compression ratio and Cobb angle were used to evaluate the operation effect before and after the operation.According to the criteria that the height of the anterior edge of the injured vertebrae decreased by more than 15% or the angle increased by more than 10° during the follow-up,the patients were divided into two groups: the uncompressed group and the recompression group.By collecting the general data of the patients,we speculated that the related factors of the recompression of the injured vertebrae might include age,gender,bone density,body mass index,volume of the injected bone cement,leakage of bone cement,lumpy distribution of bone cement,restoration effect of the vertebrae,existence of intravertebral cleft(IVC),and the contact between bone cement and upper and lower endplates.T-test,single and multiple logistic regression analysis were used to evaluate the related factors of vertebral body recompression.Results:A total of 120 patients were included in the study.X-ray was reexamined during follow-up.According to the standard of recompression,they were divided into two groups: the uncompressed group(88 patients)and the compression group(32 patients).All the patients' pain symptoms were relieved,the heights of the injured vertebraes were recovered,and the Cobb angles were corrected.Compared with the preoperative,there were significant differences in VAS score(P<0.001),ODI index(P<0.001),vertebral compression ratio(P<0.001)and Cobb angle(P<0.001)between the uncompressed and the compression group.Univariate logistic regression analysis on the factors that may affect the decompression of the injured vertebrae showed that the recompression of injured vertebrae was related to bone density(P<0.001),the distribution of bone cement clumps(P=0.026),the corrected compression ratio of vertebrae(P=0.009),corrected Cobb angle(P=0.018)),and the failure of bone cement to contact the upper and lower endplates at the same time(P=0.013).Multivariate logistic regression analysis showed that the lower bone mineral density(OR=10.322,P<0.001),the distribution of cement clumps(OR=1.182,P=0.035),the corrected compression ratio of vertebrae(OR=3.217,P=0.012),the corrected Cobb angle(OR=1.877,P=0.028)and the lack of contact between the cement and the upper and lower endplates(OR=2.247,P=0.017)were the independent risk factors of the recompression of the injured vertebra.Conclusions:PKP is an effective method to treat OVCF.Low bone mineral density,lumpy distribution of bone cement,excessive correction of injured vertebrae,and bone cement not in contact with upper and lower endplates at the same time are risk factors for injured vertebrae recompression after PKP in OVCF patients.