Background:

Static interbody spacers are standard of care for minimally invasive lateral lumbar interbody fusion (MIS LLIF). However, placement of large static interbody spacers typically requires multiple trialing, endplate preparation, and forceful impaction. A lateral expandable interbody spacer with adjustable lordosis can be inserted at a reduced height, to optimize the endplate-to-endplate fit. This study describes radiographic and clinical outcomes in patients treated using lateral titanium expandable interbody spacers with adjustable lordosis using MIS LLIF.

Methods:

This is a single-surgeon, retrospective, institutional review board-exempt chart review of 24 consecutive patients who underwent MIS LLIF at 1-2 contiguous level(s) using expandable spacers with adjustable lordosis. Radiographic and clinical functional outcomes were collected and compared at preoperative and postoperative time points up to 24 months. Parametric and nonparametric tests were used when appropriate. Statistical results were significant if P < .05.

Results:

Twenty-four consecutive patients were evaluated with an average age of 57.8 ± 12.6 years; 45.8% were female. Visual analog scale for back pain improved by 7.3 ± 1.0 points, whereas Oswestry Disability Index scores improved by a mean of 67.5 ± 11.3 points at 24 months (P < .001). Lumbar lordosis improved by a mean of 6.3 ± 10.1° at 24 months (P < .001). There were 29 spinal levels, with 41.4% at L4-5 and 34.5% at L3-4. Anterior, middle, and posterior disc height significantly increased at 24 months by means of 4.5 ± 2.9 mm, 4.0 ± 2.8 mm, and 2.6 ± 1.9 mm, respectively (P < .001). Neuroforaminal height significantly improved by 3.3 ± 3.9 mm at 24 months (P < .001). Segmental lordosis improved by 3.6 ± 3.0° at 24 months.

Conclusions:

This study showed significant positive clinical and radiographic outcomes for patients who underwent MIS LLIF using expandable interbody spacers with adjustable lordosis. Correction of sagittal alignment was achieved and maintained up to 2-year follow-up. The use of expandable spacers with adjustable lordosis was shown to be safe and effective in this cohort.

Level of evidence:

3.