[Effect of percutaneous kyphoplasty with different phases bone cement for treatment of osteoporotic vertebral compression fractures].

OBJECTIVE: To compare the effect of percutaneous kyphoplasty (PKP) with different phases bone cement for treatment of osteoporotic vertebral compression fracture (OVCF).
METHODS: The clinical data of 219 OVCF patients who treated with PKP and met the selection criteria between June 2016 and May 2018 were retrospectively analyzed. According to the different time of intraoperative injection of bone cement, they were divided into observation group [116 cases, intraoperative injection of polymethyl methacrylate (PMMA) bone cement in low-viscosity wet-sand phase)] and control group (103 cases, intraoperative injection of PMMA bone cement in low-viscosity wire-drawing phase). There was no significance in general date of gender, age, disease duration, body mass index, bone mineral density T value, fracture vertebral body, preoperative fracture severity of the responsible vertebral body, anterior height ratio of the responsible vertebral body, preoperative pain visual analogue scale (VAS) score, and Oswestry disability index (ODI) between the two groups ( P>0.05). The VAS score and ODI score were used to evaluate the improvement of patients' symptoms at immediate, 2 days, 3 months after operation and at last follow-up. At 1 day, 3 months after operation, and at last follow-up, X-ray film and CT of spine were reexamined to observe the distribution of bone cement in the vertebral body, bone cement leakage, and other complications. During the follow-up, the refracture rate of the responsible vertebral body and the fracture rate of the adjacent vertebral body were recorded.
RESULTS: The injection amount of bone cement in the observation group and control group were (4.53±0.45) mL and (4.49±0.57) mL, respectively, showing no significant difference between the two groups ( t=1.018, P=0.310). Patients in both groups were followed up 6-18 months (mean, 13.3 months). There were 95 cases (81.9%) and 72 cases (69.9%) of the bone cement distribution range more than 49% of the cross-sectional area of the vertebral body in the observation group and the control group, respectively, showing significant difference in the incidence between the two groups ( χ 2=4.334, P=0.037). The VAS score and ODI score of the postoperative time points were significantly improved compared with those before operation ( P<0.05), and there were significant differences among the postoperative time points ( P<0.05). The VAS score and ODI score of the observation group were significantly better than those of the control group ( P<0.05) at immediate, 2 days, and 3 months after operation, and there was no significant difference between the two groups at last follow-up ( P>0.05). At 1 day after operation, the cement leakage occurred in 18 cases of the observation group (8 cases of venous leakage, 6 cases of paravertebral leakage, 4 cases of intradiscal leakage) and in 22 cases of the control group (9 cases of venous leakage, 8 cases of paravertebral leakage, 5 cases of intradiscal leakage). There was no significant difference between the two groups ( P>0.05). During the follow-up, 5 cases (4.3%) in the observation group, 12 cases (11.7%) in the control group had responsible vertebral refracture, and 6 cases (5.2%) in the observation group and 14 cases (13.6%) in the control group had adjacent vertebral fracture, the differences were significant ( χ 2=4.105, P=0.043; χ 2=4.661, P=0.031).
CONCLUSION: Bone cement injection with wet-sand phase in PKP is beneficial for the bone cement evenly distributed, strengthening the responsible vertebral, relieving the short-term pain after operation, decreasing the rate of responsible vertebral refracture and adjacent vertebral fracture without increasing the incidence of relevant complications and can enhance the effectiveness.