#435 Failure of Indirect Decompression with the Extreme Lateral Interbody (XLIF) Approach: A Study of Radiographic Factors

General Session: Lateral Interbody Fusion

Presented by: I. Karikari

Author(s):

I. Karikari (1)
O. Adogwa (1)
T. Owens (2)
K. Knott (2)
C. Brown (1)
L. Pimenta (3)
R. Isaacs (1)

(1) Duke University Medical Center, Durham, NC, USA
(2) Duke University, Durham, NC, USA
(3) Instituto de Patologia de Coluna, Sao Paulo, Brazil

Abstract

Objective: The purpose of this study is to determine the radiological factors that are predictive of failure of indirect decompression with the XLIF procedure.

Introduction: The XLIF procedure provides a unique access to the anterior thoracic and lumbar spine through a lateral transpsoas and has become a key component of the spine surgeon's armamentarium. Symptomatic lumbar central, lateral recess and foraminal stenosis remains the most common indication for the procedure. Despite recent reports of successful outcomes with the XLIF procedure, a subset of patients have not achieved such outcomes due to failure of indirect decompression. The pre-and postoperative radiographic factors predictive of failure of indirect decompression has not been previously studied. In this study, we retrospectively reviewed and analyzed radiographic factors on a consecutive number of patients who either failed or improved following the XLIF procedure.

Study Design: Retrospective review of prospective collected data on 40 patients undergoing indirect decompression with the extreme lateral interbody (XLIF) approach.

Methods: A retrospective review of 40 consecutive patient's pre-operative, post-operative and 3- and 6-month follow-up radiographs was performed. All patients had XLIF procedure for lumbar degenerative disease, spondylolisthesis, spinal stenosis or de novo scoliosis. Radiographic parameters of interest included (1) right and left subarticular diameter, (2) sagittal and axial central canal area, (3) disc height, (4) foraminal height and area and (5) facet arthopathy grade. The radiographs were also analyzed for fusion at 6-months, end-plate fracture, graft subsidence and other complications. Independent variables predictive of post-operative failure were assess via a multivariate logistic regression.

Results: Both patient cohorts were similar at baseline, Table 1. The mean±SD deviation age was 66.25 ± 9.84 years, Table 1. The median [Inter Quartile Range] number of levels decompressed was 2 [1 - 2]. Overall, the mean±SD right subarticular distance at L4 - L5 was 2.14 ± 1.29mm [Responders: 2.62mm ± 1.29mm, Non-responders: 1.69mm ± 1.16mm, p=0.03], Table 2. Overall, the mean±SD anterior and posterior disc height at L4 - L5 was 7.98mm ± 3.37mm and 6.08 ± 2.02mm, Table 3. Independent of patient age, disc height, foraminal area and diameter, anterior disc height, number of levels fused, central canal and diameter and facet arthopathy Grade, decreasing subarticular diameter and posterior disc height were independently predictive of post-operative failure of indirect decompression.

Conclusions: Our study suggests that independent of a technically excellent surgery, patients with decreased subarticular diameter and posterior disc height were more likely to fail index XLIF surgery.

Table 1

Table 2