J. H. Mooney1, J. Amburgy1, M. Self1, P. Pritchard1, B. Agee1, M. R. Chambers1 1University Of Alabama at Birmingham,Neurosurgery,Birmingham, Alabama, USA
Introduction:
Kyphoplasty is a minimally invasive surgery developed to restore height and stabilize painful vertebral compression fractures (VCFs). There is an abundance of published data illustrating reduction of pain, disability and improved quality of life following kyphoplasty. However, there has been no clear correlation between patient outcomes and the volume of cement injected or degree of vertebral height restoration. The objective of this analysis is to determine if cement volume or height restoration following kyphoplasty correlate with improvements in pain, disability, and quality of life.
Methods:
In this case series, we assessed outcomes following kyphoplasty in 136 Medicare-eligible patients with 1 to 3 painful VCFs between T5 and L5 due to osteoporosis or cancer. The total volume of bone cement injected at each level was recorded for each patient. Anterior, middle, and posterior vertebral body heights were measured in fifty-nine patients pre and post-operatively utilizing computerized lateral thoracic and/or lumbar radiographs. Patient outcomes were evaluated before and after surgery. The Visual Analog Scale (VAS, range: 0(none) – 10(worst)) was used to prospectively measure back pain preoperatively in all patients. Pre and post-operative measurements of disability and quality of life were retrospectively collected using the Roland Morris Disability Questionnaire (RMDI, range: 0(no disability) -24(high disability)) and EuroQol 5-Domain scale (EQ5D, range: -0.11(poor quality of life) – 1.0(perfect health)). Pearson correlations as well as linear regression models were derived for association of total cement volume and vertebral height restoration with patient outcomes.
Results:
For VAS, RMDI, and EQ5D improvements, neither Pearson correlations (r= 0.042, 0.167, and 0.091), respectively, nor multiple linear regression models (R²= 0.002, 0.029, 0.023), respectively, reveal either a correlation or an association with total cement volume. Additionally, neither Pearson correlations (r coefficients ranging from 0.001-0.152) nor linear regression models (R² values ranging from 0.0002-0.1133) reveal either correlation or association between anterior, middle, or posterior vertebral body height improvements with VAS, RMDI or EQ5D improvements.
Conclusion:
This is the largest known study to assess associations of vertebral body height improvements and cement volumes with patient outcomes. Most patients improved regardless of the vertebral height improvements or cement volumes injected.