[Treatment of thoracolumbar junction burst fractures (Magerl A3) by balloon kyphoplasty: anatomic study]

Abstract

Purpose of the study: Balloon kyphoplasty is a not widely used method for the treatment of vertebral burst fractures with displacement of the posterior wall. The purpose of this study was to measure the posterior height of the vertebral body and the posttraumatic canal surface area before and after balloon kyphoplasty for the treatment of burst fractures (Magerl A3).

Material and methods: This anatomic study was conducted on ten experimental burst fractures of the thoracolumar junction prepared on cadaver specimens. The surface area of the canal and the height of the posterior wall were measured by computed tomography before and after balloon kyphoplasty. These two variables were then compared with search for correlation.

Results: The posttraumatic canal surface area increased significantly after kyphoplasty (p=0.02). Gain in posterior height was not significant and there was no correlation between the two variables. Cement leakage into the canal was not observed.

Discussion: It is known that balloon kyphoplasty can re-establish anterior height and correct for the posttraumatic kyphosis in patients with compression fractures of osteoporotic vertebrae. The present cadaver study shows that when the posterior wall is displaced posteriorly, balloon expansion does not exaggerate the wall displacement. On the contrary, the posttraumatic canal surface area is increased due to the ligamentotaxis effect.

Conclusion: Balloon kyphoplasty could be an alternative to posterior instrumentation for burst fractures without associated neurological deficit, even if the posterior wall is damaged. This technique can be used to reduce and stabilize the fracture while sparing the adjacent levels and limiting the risk inherent with an extensive surgical approach.