[The correlation analysis of balloon volume and bone cement volume in percutaneous kyphoplasty]

To analyze the percutaneous kyphoplasty (PKP) data statistically to predict the bone cement volume (CV).

Retrospective analysis of 93 patients with 154 vertebrae of osteoporotic vertebra compressed fracture, who received PKP from January 2012 to December 2013 in Beijing Tian Tan Hospital, Capital Medical University. All procedures were bilateral and non-high-pressure polymethyl methacrylate injection. The balloon volume (BV), balloon peak pressure (Pmax), CV and the ratio of Pmax to BV (P/BV) were documented. The data was analyzed by correlation analysis and linear regression analysis to reveal the correlation between BV and CV.

Seven vertebrae had bone cement leakage, no intraspinal leakage, no neuro-deficit. Visual analogue scale was 0-2 of all patients on 3 d postoperation. The data of 147 vertebrae without leakage: BV was 2.1-6.3 ml, Pmax was 130-359 psi, CV was 2.8-8.5 ml, and the ratio of Pmax to BV (P/BV) was 25-263 psi/ml. The data analysis showed there was no high correlation between BV and CV as one group (R<0.75). However if divided the data into three groups by the value of P/BV, group A (P/BV<100), group B (100≤P/BV<200), group C (P/BV≥200), there was high correlation and linear relationship between BV and CV in each group (R>0.75, P<0.01). CV was 0.9-1.1 times of BV in group A; CV was 1.4-1.6 times of BV in group B; and CV was 2.0-2.2 times of BV in group C.

CV is predictable by the BV and the ratio of Pmax to BV. It can reduce the rate of the leakage, and also can prevent the unsatisfactory results by insufficient bone cement volume.