Safety and Effectiveness of Expandable Intravertebral Implant Use for Thoracolumbar Burst Fractures

Purpose: To determine the safety and effectiveness of an expandable intravertebral implant (Spinejack; Stryker, Kalamazoo, Michigan) as a treatment option for patients with thoracolumbar spine burst fractures without fracture-related neurologic deficit. Materials and Methods: Imaging studies before and after expandable intravertebral implantation and medical records of 33 patients, 11 (33.3%) men and 22 (66.6%) women with an overall mean age of 71.7 years ± 8.3, were reviewed for 60 thoracolumbar Magerl Type A3 injuries secondary to osteoporosis, trauma, or malignancy. The mean follow-up time was 299 days. Results: Implantation of an expandable intravertebral device resulted in a statistically significant reduction in bone fragment retropulsion (mean ± SD, 0.64 mm ± 16.4; P < .001), reduction in the extent of canal compromise (mean, 5.5%; P < .001), increased central canal diameter (mean ± SD, 0.71 mm ± 1.3; P < .001), and restoration of vertebral body height, with a mean increase of 5.0 mm (P < .001). However, the implantation did not result in a statistically significant kyphosis reduction (mean, 1.38°; P = .10). All patients except for 1 reported improvement in pain after surgery, with a mean improvement of 1.54 on a 4-point pain scale (P < .001). No clinically significant adverse events were reported. Conclusions: This study suggests that expandable intravertebral device implantation is a safe and effective treatment for thoracolumbar vertebral burst fractures in patients without fracture-related neurologic deficit. Although implantation did not result in a statistically significant reduction in kyphotic angle, it offered significant improvement in pain, vertebral body height, fracture fragment retropulsion, and central canal diameter compromise.