Percutaneous Kyphoplasty Evaluated by Cement
Volume and Distribution: An Analysis of Clinical
Data
Authors: Hao Dingjun 
Published: February 2021

Background: Percutaneous kyphoplasty (PKP) could achieve rapid pain relief for older patients
with osteoporotic vertebral compression fractures (OVCFs). Bone cement in PKP was the key
factor keeping the stabilization of the vertebral body. However, the same amount of cement can
distribute differently in a vertebral body and can thereby result in different surgery outcomes.
Therefore, the volume and distribution of bone cement should be considered as 2 distinct variables
to evaluate the effectiveness of PKP.
Objectives: On the basis of comparing surgery outcomes between patients with different
recovery states measured by visual analog scores (VAS) and exploring the relationships among
bone cement, surgery outcomes, and degrees of pain relief, the objective of the study is to
determine the best combination of cement volume and cement distribution for PKP.
Study Design: Retrospective study.
Methods: There were 220 patients with 220 vertebra who received PKP in our hospital from
January 2011 to January 2013. According to the different pain relief degrees, patients were
divided into 2 groups. The epidemiological data, surgical outcomes, and complications were
compared between the 2 groups. A receiver operating characteristic curve (ROC) was used to
analyze the diagnostic value of bone cement on patient recovery state. A correlation analysis was
used to analyze the relationships between bone cement and surgery outcomes. Moreover, logistic
regression was also used to assess the safety of cement injection.
Results: There were 77 recuperators and 143 non-recuperators in our study. There were no
differences in epidemiological data between the 2 groups. However, the surgery duration, cement
volume, cement distribution, restoration rate of vertebral height, and improvement of kyphotic angle
in the recuperator group were all higher than those in the non-recuperator group. The area under the
ROC curve of cement distribution as a predictor of pain relief was better than that of cement volume
(0.77 vs. 0.65, P < 0.05). Cement distribution had a sensitivity of 62% and a specificity of 84% when
it was at 0.49. Cement volume had a sensitivity of 49% and a specificity of 82% when it was at 3.80
mL. All patients were then divided into 4 parts based on the 2 values. Extensive cement distribution
(more than or equal to 0.49) was discovered to noticeably increase the recuperative rate both for a
small cement volume (less than 3.80 mL) and a large cement volume (more than or equal to 3.80
mL). A small cement volume with an extensive distribution had the same recuperative effect as a large
cement volume with a confined distribution (χ2 = 2.880, P = 0.090). When the cement volume was
constant, cement distribution was positively correlated with the restoration rate of vertebral height and
improvement of the kyphotic angle (r2 = 0.207, P < 0.01; r2 = 0.159, P = 0.02), but cement distribution
was not a risk factor for cement leakage or adjacent vertebral fractures (OR = 35.760, 95%CI: 0.096 –
13291.207, P > 0.05; OR = 0.051, 95% CI: 0.011 – 1.032, P > 0.05). Although a large cement volume
may contribute to the restoration of vertebral height (r2 = 0.153, P < 0.05), it was found to be a risk
factor for adjacent vertebral fractures (OR = 1.733, 95% CI: 1.158 – 2.595, P < 0.05).
Limitations: The distribution of cement in fractured vertebra was not calcuated accurately.
Conclusions: The diagnostic value of cement distribution is better than that for cement volume
in relieving patient pain. A cement distribution above 0.49 with a small cement volume should be suggested for PKP. An extensive cement distribution can improve the kyphotic angle and vertebral height effectively, and it does
not cause cement leakage or adjacent vertebral fractures.
Key words: Psteoporotic vertebral compression fractures percutaneous kyphoplasty cement volume cement distribution