Risk factors and prediction model of refracture after percutaneous vertebroplasty and percutaneous kyphoplasty for osteoporotic thoracolumbar fracture

English Keywords:Thoracolumbar fracture  Osteoporosis  Percutaneous vertebroplasty  Percutaneous kyphoplasty  Vertebral refracture

English Abstract:

  【Abstract】 Objectives: To explore and analyze the risk factors of vertebral refractures after percutaneous vertebroplasty(PVP) or percutaneous kyphoplasty(PKP) for osteoporotic thoracolumbar fractures and to establish a prediction model. Methods: The data of 130 patients diagnosed with osteoporotic thoracolumbar fractures who underwent PVP or PKP surgery in our hospital between January 2015 and December 2019 were retrospectively analyzed. There were 33 males and 97 females, averaged 70.20±8.46(55-92) years old and were followed up for 14.75±2.17(12-22) months. According to whether occured vertebral refracture after surgery, the patients were divided into the refracture group(n=26) and non-refracture group(n=104). Parameters such as age, gender, body mass index(BMI), bone mineral density(BMD), history of fracture, number of operative vertebrae, PVP/PKP, the difference between preoperative and postoperative anterior vertebral height(AVH), the difference between preoperative and postoperative segmental kyphosis(SK), the average volume of bone cement injection, and with/without cement leakage were compared between the two groups. And the statistically significant factors in univariate factor analysis were included in multivariate logistic regression analysis, based on which, a prediction model of the risk of vertebral refractures after PVP/PKP for osteoporotic thoracolumbar fractures was established, and it was verified according to the receiver operating characteristic curve(ROC), decision-making curve and calibration curve. Results: Univariate analysis and multivariate logistic analysis showed that old age[odds ratio(OR)=44.33, 95% confidence interval(CI)=2.98-659.51, P=0.0059], lower BMD(OR=10.70, 95%CI=2.50-45.75, P=0.0014), history of fractures(OR=14.76, 95%CI=2.40-90.57, P=0.0036) and multiple surgical segments(OR=6.36, 95%CI=1.51-26.72, P=0.0115) were the independent risk factors for vertebral refracture after PVP/PKP for osteoporotic thoracolumbar fracture patients(P＜0.05). A risk prediction model of vertebral refracture after PVP/PKP for osteoporotic thoracolumbar fracture patients was established based on logistic regression, and thus a nomograph was drawn. The prediction model was verified with good fitting effect according to ROC, decision-making curve and calibration curve. Conclusions: Old age, lower BMD, multiple surgical segments, history of fractures are independent risk factors of refracture after PVP/PKP for osteoporotic throacolumbar fracture. The prediction model of the risk of vertebral refracture in patients with osteoporotic thoracolumbar fracture after PVP/PKP is well fitted, which provides a reference for evaluating the risk of secondary fracture after surgery.