Lateral lumbar interbody fusion: clinical and radiographic outcomes at 1 year: a preliminary report.

STUDY DESIGN

A retrospective review of patients' radiographs and charts.

BACKGROUND

The various methods of lumbar interbody fusion have been described in the literature. With the development of the lateral lumbar interbody fusion (LLIF) approach, a wider cage can be inserted in the intervertebral space without disrupting the anterior-posterior annulus or longitudinal ligament, with minimal danger to the retroperitoneal structures and the great vessels. There is a paucity of the literature on the radiographic and clinical outcome of this approach.

OBJECTIVE

The purpose of this study is to assess the radiographic change in the coronal and sagittal plane alignment of the lumbar spine after the LLIF approach using XLIF cages (Nuvasive, Inc, San Diego, CA). Radiographic and clinical outcomes, and complications associated with the approach are also described.

METHODS

A retrospective review of 43 consecutive patients' preoperative, immediate postoperative, and 1-year follow-up radiographs was done. All patients had LLIF procedure performed for lumbar degenerative disc disease, spondylolisthesis, or de novo scoliosis. The radiographic measurements were taken to assess change in the sagittal and coronal plane alignment of the individual instrumented disc level, overall lumbar spine, and lumbar scoliotic curves. The radiographs were also analyzed for fusion at 1 year, end-plate fracture, and other complications. The patients' hospital and clinic charts were reviewed to identify the complications and patient outcomes.

RESULTS

There was a mean correction of 3.7 degrees (P≤0.001) at each instrumented disc level in coronal plane in 87 instrumented levels. Similarly, there was a mean gain of 2.8 degrees (P≤0.001) of lordosis at each level. In 25 patients with lumbar scoliosis (>10 degrees), mean scoliosis angle correction was 10.4 degrees (P=0.001, 43%). There was no significant change in the overall coronal or sagittal plane alignment of the lumbar spine. The most common postoperative complication (25%) was anterior thigh pain, which was transitory in the majority of cases. End-plate breach was common at the instrumented disc levels; however, it was nonprogressive in most of the cases, and did not affect the fusion or alignment at the instrumented levels. The outcome scores were improved significantly at the final follow-up.

CONCLUSION

The LLIF approach is effective in correcting the coronal plane deformity and in gaining lordosis at individual instrumented levels. They parallelize adjacent end plates to correct the lumbar scoliotic curves. The complications are mostly approach-related and transitory. A larger cohort with long-term follow-up is required to establish the advantages and shortcomings of the procedure.