Fig. 4

Typical case 1: A 70-year-old male patient presented with numbness of both lower limbs for more than 5 years, aggravated with left lower limb weakness for more than 1 month.Diagnosis of L4-5 spinal stenosis. L4-5 single segment OLIF combined with posterior L4-5 percutaneous internal fixation was performed. 1a, 1b Anteroposterior and lateral X-ray films of lumbar spine before operation showed lumbar degeneration. 1c Preoperative sagittal T2 MRI of the lumbar spine showed spinal stenosis in L4-5 segment, and RNRs above the stenosis plane. 1d Postoperative sagittal T2 MRI of the lumbar spine showed that RNRs still existed above the L4-5 surgical segment. 1e, 1f Axial T2 MRI of lumbar spine before and after operation showed that the dural sac CSA increased significantly after OLIF indirect decompression. 1g, 1h At the last follow-up, the X-ray film of the lumbar spine showed that the L4-5 pedicle screw was fixed and the fusion cage was placed in a good position