Insights on Kyphoplasty: A Retrospective Analysis of Intraoperative Variables and Patient Demographics

Background Context: Vertebral compression fractures are the most common fragility fracture in the world and, with an increasing elderly population, are predicted to comprise a significant portion of spinal health care costs. Although kyphoplasty is accepted as a common treatment option, further details of its procedural aspects are less well established. Purpose: This study aimed to highlight the relationships between age, sex, and spinal levels treated by kyphoplasty and balloon pressure, volume, and cement volume. Study Design: Single Surgeon Observation Study Patient Sample: 77 patients with VCF undergoing kyphoplasty with the author (SRH) between April 2023 to September 2024. Methods: Procedural kyphoplasty measurements of balloon pressure, balloon volume, and cement volume were recorded. The inclusion criteria included patients with known osteoporotic fracture and failure of non-operative management. Only patients with acute or subacute osteoporotic compression fractures were included. Exclusion criteria included previous surgery at the spinal level and VCF due to non-osteoporotic etiology (i.e. trauma or neoplasm). Results: A total of 141 levels were included in this study. There were 77 patients; 61% female, 39% male. 54 thoracic levels were treated with a mean age of 77.0 (females) and 74.7 (males). 87 lumbar levels were treated, with a mean age of 79.3 (females) and 77.9 (males). There was a statistically significant relationship between age (by decade) and region (T vs. L spine) (p=.013). Of the 77 patients, 19% underwent surgery on multiple dates (n=15). Pressure analysis revealed that the mean inflation pressure was 152.5 PSI for thoracic spine levels and 147.5 PSI for lumbar spine levels. This was not statistically significant but there was a significant correlation between age by decade and the mean pressure (p=0.0014). When spinal levels were grouped anatomically (T6-9, T10-L1, L2-5), there was a statistically significant relationship between spinal grouping and pressure (p=0.044). The mean balloon volume was 2.42 cc for the thoracic spine levels and 2.89 cc for the lumbar spine levels. Balloon volume and age by decade were significant, with a (p=0.0137). In addition, statistically significant relationships were identified between balloon volume and level (p=0.014) and between balloon volume and age by decade (p=0.003). However, no statistically significant correlation was found between balloon volume and sex. The mean cement volume was 2.27 cc for the thoracic spine levels and 2.92 cc for the lumbar spine levels. Cement volume demonstrated a significant relationship with spinal level (p<.001). Cement volume analysis revealed a statistically significant relationship between mean cement volume and sex (p = 0.0255, two-way ANOVA). Males required higher cement volumes than females (p<.0001). Cement volume significantly correlated with age by decade (p=0.034). Advanced age requires a higher cement volume. Conclusion: Age, sex, and spinal level can significantly influence procedural components during kyphoplasty for osteoporotic VCF. Both thoracic and lumbar fractures have different procedural requirements, with greater demands on the balloon and cement quantities at the lumbar levels. Variations in sex and age emphasize the importance of personalized surgical planning in the optimization of patient outcomes.