Bone cement distribution form and diffusion degree after percutaneous vertebroplasty: an analysis based on Mimics software and its clinical significance / 中国组织工程研究

ABSTRACT

BACKGROUND: It has been found that the distribution and diffusion degree of bone cement are the main factors influencing the clinical effect of percutaneous vertebroplasty. OBJECTIVE: To explore the feasibility of analyzing bone cement distribution form and diffusion degree based on Mimics software, and to evaluate the relationship of clinical efficacy with bone cement distribution form and diffusion degree. METHODS: A total of 170 cases of osteoporotic vertebral compression fracture admitted to Zigong No. 4 People's Hospital from January 2017 to March 2018 were included, including 41 cases of males and 129 cases of females aged 60-97 years. All of them were treated with percutaneous vertebroplasty. X-ray and CT examination were done at postoperative 2 days, and the bone cement distribution was classified into five types based on the distribution of bone cement in X-ray images, including type Ⅰ (most cement continuously and evenly distributed in the vertebral body), type Ⅱ (most cement distributed in the central vertebral bodies), type Ⅲ (most cement distributed on both sides of vertebral body), type Ⅳ (most cement distribution at the side of the vertebral bodies and the central), type Ⅴ (most cement distribution at the side of the vertebral body). Mimics project files were created based on CT image data to calculate bone cement volume and diffusion volume. After 6 months of follow-up, visual analogue scale score, Oswestry disability index and Cobb angle were compared among groups to analyze the relationship between bone cement distribution, bone cement diffusion volume, bone cement diffusion volume ratio and clinical efficacy. RESULTS AND CONCLUSION: (1) The visual analogue scale score and Oswestry disability index of the five types of bone cements were significantly improved at 2 days and 6 months after surgery compared with preoperative data (P < 0.05), the Cobb angle of the type Ⅰ group was significantly improved compared with preoperative data (P < 0.05), and the Cobb angles of the type Ⅱ-Ⅴ groups showed no difference from the preoperative data (P> 0.05). (2) The diffusion volume of bone cement was (6.69±1.19) mL, and the diffusion volume ratio of bone cement was (20.93±3.13) ％. There was no correlation between the volume of bone cement injection and the visual analogue scale score, Oswestry disability index and Cobb angle at 2 days and 6 months after surgery. There was a negative correlation between the bone cement dispersion volume and the visual analogue scale score at 6 months after surgery, and the Oswestry disability index score at 2 days and 6 months after surgery (P < 0.05), but the correlation was weak. The diffusion volume ratio of bone cement was negatively correlated with the visual analogue scale score and Oswestry disability index score at 2 days and 6 months after surgery (P < 0.05), showing a strong correlation. These findings show that, based on the three-dimensional reconstruction function of Mimics software, the diffusion volume and diffusion volume ratio of bone cement can be accurately calculated. The bone cement evenly distributed can alleviate the local kyphosis. The diffusion volume ratio of bone cement is positively correlated with clinical efficacy, which is more valuable than the volume of bone cement.