Indirect decompression of oblique lateral interbody fusion for degenerated lumbar disease

Objective To examine the radiographic efficacy of indirect decompression of oblique lumbar interbody fusion (OLIF) for lumbar degenerated disease. Methods Thirty consecutive patients were enrolled into this study who presented with lumbar degenerated disease and underwent OLIF without posterior decompression from October 2016 to April 2017 at Neurosurgery Department of Xuanwu Hospital, Capital Medical University. The imaging, clinical efficacy and complications were retrospectively reviewed. X-Ray, CT scan and MRI before operation and at the last follow-up were evaluated. The cross-sectional area (CSA) of the thecal sac was measured on T2WI axial MRI. The disk height (DH), cross-sectional height (CSH) of intervertebral foramina and cross-sectional areas of intervertebral foramina (CSAF) were measured on sagittal view of CT. Visual analog scale (VAS) score, Oswestry disability index (ODI) and medical outcome study 36-item short-form health survey (SF-36) were evaluated before operation and at the last follow-up. Results A total of 62 lumbar levels of OLIF fusion in 30 patients were performed successfully without severe complications. Our follow-up study lasted 9-15 months with an average of 12.5±2.3 months.The mean CSA increased from 0.82±0.34 cm2 preoperatively to 1.38±0.37 cm2 postoperatively, DH increased from 0.68±0.24 cm preoperatively to 1.13±0.29 cm postoperatively, CSH increased from 1.53±0.25 cm preoperatively to 2.05±0.32 cm postoperatively, and CSAF increased from 1.12±0.28 cm2 preoperatively to 1.80±0.37 cm2 postoperatively (all P<0.01). The VAS, ODI and SF-36 scores were significantly improved after surgery (all P<0.05). There was no spinal nerve, major vessel, peritoneal, or urinary injury. Only 1 patient showed symptoms related to psoas invasion. Conclusion Significant improvements in CSA, DH, CSH and CSAF could be obtained following OLIF surgery for degenerated lumbar disease with good clinical and imaging outcomes. Key words: Spinal diseases; Lumbar vertebrae; Photogrammetry; Oblique lateral interbody fusion; Treatment outcome