Zeitschrift für Wirbelsäule

Proximal Junctional Kyphosis Following Thoracolumbar Fusion Ending at the Lower Thoracic Spine: The Effect of Cement Augmentation

Abstract

Rahul G Samtani*, Anthony Ho, James Bernatz, Zachary Napier and Joseph Ro-Brien

Study design: A retrospective comparative study.

Objective: The purpose of this study was to evaluate the role of cement augmentation in reducing the incidence of fractures and/or kyphosis at the proximal junction following treatment for adult thoracolumbar spinal deformity that ends at the lower thoracic spine.

Summary of background data: Proximal junctional kyphosis may occur due to ligamentous relaxation or fracture of the proximal vertebrae. The role of cement augmentation in preventing proximal junctional kyphosis or failure is unclear.

Methods: This study is a retrospective review of 25 patients who underwent >6 levels of instrumented fusion. Patients were divided into two groups according to whether or not they received cement augmentation at the upper instrumented vertebrae. All fusions had the lower thoracic spine as the cranial stopping point and S1 as the most caudal level.

Results: The mean age was 60.0 (range, 33-81), and the mean levels fused was 8.3 (range, 6-12). Average follow up was 20.4 months (range, 6-55). Six patients (24%) had acute proximal junctional kyphosis, two of whom did not receive cement augmentation and four of whom did. Of those patients, one was due to fracture in each group (P>0.05). However, the patient with cement and fracture leading to revision was not compliant with precautions due to delirium post operatively. Spinopelvic and regional spine measurements were statistically similar between the two groups.

Conclusion: Cement augmentation may prevent proximal junctional failure due to fracture, however, ligamentous proximal junctional kyphosis was seen in both the cemented and uncemented groups. Larger scale studies are required to further delineate the potential benefits of cement augmentation of the proximal aspect of thoracolumbar fusions stopping at the lower thoracic level.