RT Journal Article
SR Electronic
T1 Minimally Invasive Lumbar Interbody Fusion With an Expandable Meshed Allograft Containment Device: Analysis of Subsidence With 12-Month Minimum Follow-Up
JF International Journal of Spine Surgery
JO Int J Spine Surg
FD International Society for the Advancement of Spine Surgery
SP 6044
DO 10.14444/6044
A1 Kolcun, John Paul G.
A1 Ghobrial, George M.
A1 Crandall, Kenneth M.
A1 Chang, Ken Hsuan-Kan
A1 Pacchiorotti, Giacomo
A1 Wang, Michael Y.
YR 2019
UL https://www.ijssurgery.com/content/early/2019/08/19/6044.abstract
AB Study design Retrospective case seriesObjective Describe subsidence in lumbar interbody fusion using an expandable meshed allograft containment device with 12-month minimum radiographic follow-up. Background We have previously reported the use of a minimally invasive allograft-filled expandable meshed-bag containment system in the lumbar spine. Subsidence has not been reported with this device.Methods Consecutive adult patients that underwent 1- or 2-level interbody fusion with at least 1 year of follow-up were included in this study. Preoperative, postoperative, and final follow-up lumbar radiographs were analyzed to measure disc height at the anterior and posterior margins of the disc space, as well as the neuroforaminal height.Results Forty-one patients were identified, with a mean age of 63.4 years (± 11.8). A total of 61 levels were treated, with successful fusion observed in 54 levels (88.5%). The mean radiographic follow-up was 24.3 months (± 11.2). The mean disc height pre- and postoperatively was 6.9 mm (± 3.2) and 10.1 mm (± 2.9, P < .001), respectively. The mean disc height at final follow-up was 8.3 mm (± 2.4). Average disc height subsidence was 1.8 mm (± 1.7, P < .001). Overall, average disc height increased by a net 1.3 mm (± 2.5, P < .001). The mean neuroforaminal height pre- and postoperatively was 18.0 mm (± 3.3) and 20.7 mm (± 3.6, P < .001), respectively. The mean neuroforaminal height at final follow-up was 19.2 mm (± 3.4). Average neuroforaminal height subsidence was 1.3 mm (± 3.4, P = .012). Overall, average neuroforaminal height increased by a net 1.7 mm (± 2.8, P = .004). No significant difference in subsidence was observed between 1- and 2-level surgeries.Conclusion An expandable allograft containment system is a feasible alternative for lumbar interbody fusion. Due to its biologic and mechanical nature, the surgeon using such constructs should account for an anticipated average of 18% loss of interbody height due to subsidence during the bony remodeling/fusion process.