Single-Level Lateral Lumbar Interbody Fusion for the Treatment of Adjacent Segment Disease

Study Design. A retrospective case series. Objective. The aim of this study was to assess the postoperative outcome after single-level lateral lumbar interbody fusion (LLIF) for adjacent segment disease (ASD). Summary of Background Data. Although there is a plethora of literature on ASD following traditional arthrodesis techniques, literature on ASD following LLIF is limited. Vice versa, the surgical outcome after LLIF for the treatment of ASD remains to be elucidated. Methods. Patients who underwent single-level LLIF for ASD at two institutions (March 2006-April 2012) were included, and the medical records, operative reports, radiographic imaging studies, and office records reviewed. Results. Out of 523 LLIF patients, 52 met the inclusion criteria, and were postoperatively followed for 16.1 +/- 9.8 months (range: 5-44). When comparing the pre-operative data with both the first and most recent follow-up postoperatively, LLIF resulted in a reduction in back pain (P<0.001, and P<0.001, respectively) and leg pain (P< 0.001, and P<0.001, respectively), increase in segmental lordosis (P = 0.003, and P = 0.014, respectively), decrease in segmental coronal angulation (P<0.001, and P = 0.003, respectively), and increase in intervertebral height (P< 0.001, and P<0.001, respectively) at the surgical level. The reoperation rate related to the LLIF procedure was 21.2% (11/52), which was performed after an average of 14.6 +/- 10.1 months (range: 3.3-31.0). Eight out of 11 patients (72.7%) in the reoperation subgroup underwent standalone LLIF, whereas only 23 out of 41 patients (56.1%) without a reoperation underwent standalone LLIF (P +/- 0.491). There was a trend toward a higher fusion rate in patients who underwent circumferential fusion than the standalone subgroup (87.5% vs. 53.8%; P = 0.173). Conclusion. LLIF may be an effective surgical treatment option for ASD with regard to both the clinical and radiographic outcome in a large proportion of cases. Although standalone LLIF is associated with a narrower spectrum of adverse effects than circumferential fusion, posterior instrumentation may be necessary to increase segmental stability.