Impact of Preoperative Diagnosis on Clinical Outcomes of Oblique Lateral Interbody Fusion for Lumbar Degenerative Disease in a Single-institution Prospective Cohort

Objectives: Oblique lateral interbody fusion is considered a useful surgical option for various lumbar degenerative diseases with favorable clinical results and few complications. However, clinical outcomes following oblique lateral interbody fusion stratified according to the preoperative diagnosis have not been fully evaluated in a large cohort. The purpose of the present study was to evaluate the clinical outcomes following oblique lateral interbody fusion for lumbar degenerative disease and to identify differences in outcomes when stratified according to preoperative diagnosis. Methods: All patients receiving oblique lateral interbody fusion for lumbar degenerative diseases were included in the current study and were stratified into four diagnostic groups: (i) degenerative spondylolisthesis; (ii) spondylolytic spondylolisthesis; (iii) spinal stenosis without spondylolisthesis and instability; and (iv) deformity. Clinical outcomes were assessed using multiple patient-reported questionnaires. Radiologic outcomes, including cage subsidence and completion of fusion, were also evaluated. Results: Overall, 169 patients with 262 operative levels were included in the study. All clinical scoring items showed significant improvement at 1year postoperatively for all diagnostic groups. Net and percent improvement, and a proportion of patients reaching a threshold for substantial clinical benefit were not significantly different between the diagnostic groups in all scoring items, except for lower extremity radiating pain of the deformity group. Although the deformity group had the highest overall complication rate, neurologic complications were more frequent in the spondylolytic spondylolisthesis group. The rate of complete fusion and cage subsidence for individual levels at 1year postoperatively was 62.7% and 32.6% respectively, with no significant difference between the diagnostic groups. Conclusions: The large single-institution prospective cohort of the present study showed favorable clinical outcomes following oblique lateral interbody fusion for lumbar degenerative disease, even in spinal stenosis without spondylolisthesis and instability.