A Retrospective Study On The Use Of Average CT Values To Quantitatively Predict The Risk Of Adjacent Vertebral Fractures After PKP

Objective:In this study,the average CT value of the operative vertebrae and the upper and lower adjacent vertebrae was measured on the CT images of the postoperative reexamination of PKP patients.Statistical analysis of the significant difference in CT values between adjacent vertebrae with fractures and adjacent vertebrae without fractures,And the significant difference in CT ratio between the operative vertebra and the adjacent vertebra with fracture and the adjacent vertebra without fracture,Determine the critical value of CT for reoccurring fractures of adjacent vertebrae and the critical value of CT ratio of operative vertebrae to adjacent vertebrae,Use critical values to predict the risk of recurring adjacent vertebrae fractures,And analyze the accuracy of this method in predicting the risk of adjacent vertebral fractures.Methods:A total of 465 cases of PKP surgery for OVCFs were collected from the Department of Spine Surgery,China-Japan Union Hospital of Jilin University from January 1,2019 to October 31,2021.Through the screening of hospitalized medical records,it was found that,There were82 patients who had other vertebral fractures after surgery and went to see the doctor again.Excluding 35 cases of clear history of high-energy trauma,non-single other vertebral fractures,and non-adjacent vertebral fractures,47 cases remained.Among them,9 were male patients and 38 were female patients.55 years old is the youngest age,91 years old is the oldest age,and the average age is 74.21±9.74 years.A retrospective analysis of the CT imaging data of 47 patients with adjacent vertebral fractures after PKP surgery.Use the PACS image reading system and the AW Pioneer image processing system to measure the average CT values of the surgical vertebrae and the upper and lower adjacent vertebrae on the CT images.Record the average CT value and measurement volume of each measurement.In this study,CT1,CT2,and CT3 were used to represent the average CT values of fractured adjacent vertebrae,non-fractured adjacent vertebrae,and operated vertebrae,respectively.The CT values of the adjacent vertebrae（CT1 and CT2）and the ratio of the CT values of the operated vertebrae to the adjacent vertebrae（CT3/CT1 and CT3/CT2）were statistically analyzed.The normal distribution test is performed on the difference in CT values of the adjacent vertebrae and the CT ratio of the operated vertebrae to the adjacent vertebrae,If the difference accepts normality,a paired-sample t test is performed on the data,If the difference rejects normality,the Wilcoxon rank sum test is performed on the data,Analyze the significance of the difference between the two sets of data.Then the CT value of the adjacent vertebrae and the CT ratio of the operated vertebrae to the adjacent vertebrae were analyzed by receiver operating characteristic curve to determine the best critical value.And evaluate the sensitivity,specificity and prediction accuracy of the corresponding cut-off value.Results:1.The average CT value（CT1）of the adjacent vertebra with fracture and the average CT value（CT2）of the adjacent vertebra without fracture were compared and analyzed,using paired sample t-test,Statistics t=12.510,degrees of freedom DF=46,P<0.0001,according to the inspection standard α=0.05,The difference between CT1 and CT2 is significant and statistically significant.2.The CT value ratios of the operated vertebrae and adjacent vertebrae with fractures and adjacent vertebrae without fracture were compared and analyzed,using Wilcoxon rank sum test,Statistics Z=5.9683,P<0.0001,according to the inspection standard α=0.05,The difference between CT3/CT1 and CT3/CT2 is significant and statistically significant.3.Interactive scatter plots of CT values of the adjacent vertebrae and the ratio of CT values of the operated vertebrae to the adjacent vertebrae show that a CT value of 67.9 HU and a CT value ratio of 15.02 can be used as a threshold value to predict the risk of fracture of the adjacent vertebrae after PKP surgery,The area under the ROC curve was 0.902 and0.872,respectively,The prediction accuracy was 90.4% and 83.0%,respectively.Conclusion:Osteoporotic vertebral compression fractures have a higher incidence of adjacent vertebrae fractures after PKP.The statistical result of this study was 10.1%（47/465）.If the risk of fracture of the adjacent vertebra is high,early intervention measures can be taken to reduce the risk of recurring fracture of the adjacent vertebra.Such as active antiosteoporosis treatment and wearing a hyperextension brace for protection.1.The average CT value of the adjacent vertebra or the ratio of the average CT value of the surgical vertebra to the adjacent vertebra can predict the risk of fracture of the adjacent vertebra.2.The low average CT value of the adjacent vertebrae or the high ratio of the average CT value of the operative vertebra to the adjacent vertebrae are risk factors for the prone to fracture of the adjacent vertebrae.3.The average CT value of the adjacent vertebra ≤ 67.9 HU or the ratio of the average CT value of the operative vertebra to the adjacent vertebra> 15.02 is the critical value for the risk of recurring fracture of the adjacent vertebra.The prediction accuracy is 90.4% and 83.0% respectively.