Minimally Invasive Endoscopic-Assisted Lateral Lumbar Interbody Fusion: Technical Report and Preliminary Results

OBJECTIVE: Lateral lumbar interbody fusion (LLIF) is a highly useful lumbar fusion surgical technique for degenerative spinal disease. However, many complications have already been reported. The purpose of this study is to report the concept, surgical technique, and clinical results of the first 70 consecutive cases treated with a safer and minimally invasive endoscopic-assisted LLIF (ELLIF). METHODS: This retrospective study included 70 cases involving 106 segments in which ELLIF was used to treat degenerative spinal disease. We examined the clinical progress, complications and analyzed radiographic images. Regarding the fusion rate, 49 cases involving 72 segments whose follow-up period was more than 7 months were evaluated. RESULTS: The mean of preoperative Numerical Rating Scale (NRS) was 7.0 and postoperative NRS was 1.4. Postoperative NRS had a significant correlation with the number of fusion segments (p = 0.028). The mean of preoperative disc space height, foraminal height, sagittal rotation angle, whole lumbar lordosis and sagittal translation distance were 3.3 mm, 14.3 mm, 2.4°, 9.7°, and 3.2 mm, respectively. Postoperative values were 9.4 mm, 17.9 mm, -4.9°, 36.3°, and 0.7 mm. The fusion rate was 79.2%. Complications included, transient psoas muscle weakness 1, sensory disturbance in the thigh 2, retroperitoneal injury 1, postoperative ileus possibly involving a retroperitoneal injury 1, and cage migration 4. CONCLUSION: Using the ELLIF in the degenerative spinal disease, we obtained good radiological reduction and good clinical results. Our study confirms that ELLIF is safer and provides better results for degenerative spinal disease. However, the issue of cage migration remains to be resolved.