Impact of Hounsfield units on adjacent fracture risk after kyphoplasty.

Abstract

Study design: retrospective cohort study.

Objective: This study aims to assess the utility of Hounsfield units (HU) derived from computed tomography (CT) scans as a predictive marker for the risk of adjacent fractures (AF) following kyphoplasty.

Methods: In a retrospective analysis at a high-volume care hospital, 93 patients who underwent single-level kyphoplasty between January 2012 and December 2020 were included. The study focused on the correlation between HU values in vertebrae adjacent to the operated level and the occurrence of AF. Patient demographics, fracture characteristics, and time to AF occurrence were recorded. Bone density was assessed using HU measurements from CT scans, focusing on the trabecular bone.

Results: The median time to AF occurrence was 10 weeks, with no significant correlation to patient demographics or fracture location. A marked association was observed between reduced bone density, as measured by HU in the vertebrae adjacent to the kyphoplasty site, and the incidence of AF. Particularly, the bone density in the vertebra immediately superior to the operated site showed a statistically significant relationship with the occurrence of AF.

Conclusion: This study underscores the potential of HU measurements in CT scans as a predictive tool for AF risk post-kyphoplasty. Reduced bone density in adjacent vertebrae emerged as a significant risk factor. These findings highlight the necessity for vigilant postoperative monitoring and a proactive approach in managing bone health in patients undergoing kyphoplasty for osteoporotic fractures.