关键词: 骨质疏松, 椎体压缩骨折, 终板骨折, 伤椎高度丢失, 后凸畸形

Abstract: BACKGROUND: Although vertebral augmentation can quickly stabilize fractures, relieve pain symptoms, and correct kyphosis, as the number of cases continues to increase, it has been clinically found that some patients have long-term kyphosis and chronic pain problems after surgery.  
OBJECTIVE: To explore the effects of endplate fractures on the loss of injured vertebral height, kyphosis and chronic pain after percutaneous vertebroplasty/percutaneous kyphoplasty.
METHODS:  A retrospective study investigated the medical records of 82 patients with osteoporotic vertebral compression fracture, who treated with percutaneous vertebroplasty/percutaneous kyphoplasty. The patients were divided into three groups according to the presence or absence of endplate fractures: unfractured group, superior vertebral endplate fracture group, and inferior endplate fracture group. The vertebral compression rate, vertebral height recovery rate, Cobb angle, and bone mineral density of each patient were measured and visual analogue scale, bone cement dispersion type, bone cement distribution area, and cement leakage were recorded. Univariate analysis and chi-square test were used to analyze whether endplate fractures were related to postoperative injury vertebral height loss, kyphosis and chronic pain, and the influence of endplate fractures on the distribution of bone cement.  
RESULTS AND CONCLUSION: (1) The height of the injured vertebrae and kyphosis in the three groups were significantly improved. In the last follow-up, all patients observed a significant decrease in the height of the anterior vertebrae and an increase in Cobb angle. The loss rate of injured vertebral height and Cobb angle in the superior vertebral and inferior endplate fracture groups were greater than those in the unfractured group (P < 0.05). (2) There was no significant difference in the preoperative visual analogue scale scores between the groups (P > 0.05). The postoperative visual analogue scale scores of the three groups were significantly lower than the preoperative scores (P < 0.05), but the last follow-up visual analogue scale scores of the endplate fracture group were higher than those of the postoperative group, while the unfractured group had no significant difference in visual analogue scale scores during the last follow-up and after operation (P > 0.05). (3) The proportion of bone cement masses and the bone cement not contacting the two endplates at the same time was significantly higher in the superior vertebral and inferior endplate fracture groups than that of the unfractured endplate group (P < 0.05). There was no significant difference between the groups with insufficient bone cement distribution at the fracture site (P > 0.05). (4) It is suggested that percutaneous vertebroplasty/percutaneous kyphoplasty can significantly improve the height of injured vertebrae, kyphosis and pain. However, long-term endplate fractures after surgery are not only related to the increased incidence of postoperative vertebral height loss and kyphosis, but also an important cause of chronic pain in patients. Other factors that affect the long-term loss of vertebral body height and the occurrence of kyphosis include the degree of bone cement dispersion, bone density, surgical methods, and bone cement materials. The degree of bone cement dispersion is affected by endplate fractures, and the lower the bone density, the more likely to fracture the endplate. Therefore, surgery should not only restore the compression height of the injured vertebrae and correct the kyphosis, but also correct the deformity of the endplate to effectively treat patients with endplate fractures.

Key words: osteoporotic, vertebral compression fracture, endplate fracture, height loss, kyphosis