2023 Volume 14 Issue 7 Pages 1023-1031
Purpose: We examined the criteria for intervertebral bony release (IBR) with lateral lumbar interbody fusion (LLIF) for intervertebral bony fusion in patients with adult spinal deformity (ASD).
Methods: We included 19 intervertebral levels in 14 patients with ASD and intervertebral bony fusion who underwent correction surgery with LLIF and percutaneous pedicle screw (PPS) fixation between 2016 and 2020. The bony fusion level, bony fusion morphology (anterior/posterior, unilateral/bilateral), and IBR procedures were evaluated. Bony fusion morphology was classified as unilateral or bilateral fusion in the anterior and posterior regions. Furthermore, posterior facet joint fusion was classified as grade 1, where the borders are bridged, and grade 2, where the borders disappear, and the joint is firmly fused. IBR procedures were classified as follows: A, LLIF only; PA, posterior osteotomy (PCO) +LLIF; PA, LLIF+PPS fixation.
Results: The average age was 69.2 years (seven men and seven women), with ten cases of adult idiopathic scoliosis being the most common. In all cases of anterior bone or anteroposterior unilateral fusion, IBR was achieved using LLIF alone in all cases of anterior bony fusion. However, in cases of anteroposterior fusion, IBR was not achieved with anterior or posterior bilateral fusion; in all cases, IBR was achieved with PCO or PPS fixation. One patient with anteroposterior fusion, bilateral posterior fusion, and a grade 2 facet joint did not achieve IBR.
Conclusion: We investigated the criteria for IBR with LLIF alone in patients with ASD and bone fusion. IBR was achieved using LLIF alone for anterior-only fusions. It was recommended that IBR with LLIF alone would be difficult if either the anterior or posterior fusion was bilateral and the facet joint was grade 2.
