An anatomical feasibility study using CTA reconstruction for modified percutaneous lumbar vertebroplasty.

Background: Lumbar vertebroplasty via several different types of extrapedicular approach has been reported with acceptable clinical results yet the anatomical basis for its safety is not fully explored. Injury to the lumbar arteries (LAs) is one of the most important potential complications. However, anatomical research on the course and variability of this structure is lacking. To investigate the anatomical feasibility of percutaneous vertebroplasty for lumbar osteoporotic vertebral compression fractures via a unilateral Extrapedicular approach.

Methods: A total of 300 LAs of 30 patients with non-spinal disorders were retrospectively analyzed by computed tomographic angiography (CTA). The lateral aspect of the vertebral body was divided into 9 zones of approximately equal area. The anatomy and orientation of LAs were analyzed in detail.

Results: LAs were most commonly found in the middle third of the body (zones 4, 5, and 6); the upper 1/3 of the vertebral body had LAs distributed only anteriorly and laterally (zones 1 and 2). No arteries were observed in the postero-superior segment (zone 3). From L1 to L3 an arched pattern predominated. At L4 an inferior oblique pattern (antero-superior to postero-inferior) predominated. Limited CTA visualization at L4 and particularly L5 as well as greater anatomical variation means that there is more uncertainty at these levels.

Conclusion: From L1 to L3, the posterior superior segment (zone 1) of the vertebral body appears to be a safe area with low risk of arterial injury. This has relevance for design of a safe lumbar vertebral extrapedicular approach.