Introduction: The XLIF procedure provides a unique access to the anterior thoracic and lumbar spine through a lateral transpsoas approach, and has become a key component of the spine surgeon’s armamentarium. Symptomatic lumbar central, lateral recess and foraminal stenosis remain the most common indication for the procedure. The purpose of this study is to determine the radiological factors that are predictive of failure of indirect decompression with the XLIF procedure
Methods: A retrospective review of 40 consecutive patient’s pre-operative, post-operative and 3- and 6-month follow-up radiographs was performed. The primary outcome was to determine the independent variables predictive of achieving a minimum 30% change from baseline in sagittal vertebral canal diameter, a threshold above while we defined as “success” of indirect decompression.
Results: The median [Inter Quartile Range] number of levels decompressed was 2 [1 – 2]. Overall, the mean±SD right and left subarticular distance at L4 – L5 was 2.09 ± 1.29 mm and 1.98 ± 1.25, respectively, Table 2. Overall, the mean±SD anterior and posterior disc height at L4 – L5 was 8.23 ± 3.37mm and 6.14 ± 2.02mm, respectively, Table 3. In a univariate regression analysis younger patient age, intervertebral disc height, foraminal area, anterior disc height, number of levels fused, posterior disc height, central canal and diameter and Facet Arthopathy grade were all significantly associated with successful indirect decompression. However, in a multivariate logistic regression model, increasing right and left subarticular diameters greater than 2.25mm and 2.35mm, respectively, and an axial central canal diameter greater than 123.1mm remained independently predictive successful indirect decompression(> 30% change in sagittal canal diameter).
Conclusions: Our study suggests that independent of a technically excellent surgery, increasing pre-operative subarticular length and axial central canal diameter are predictive of successful indirect decompression(> 30% change in sagittal canal diameter).
Patient Care: Our research will allow for better predictions of successful indirect decompression
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the indications for XLIF procedures, and 2) radiological factors that are predictive of failure of indirect decompression with the XLIF procedure