Objective To investigate the relationships between the bony structures, nerve, and indentations of ligamentum flavum of the upper lumbar spine by using CT three-dimensional reconstruction technique, in order to guide the unilateral biportal endoscopy (UBE) technique via contralateral approach in the treatment of upper lumbar disc herniation (ULDH). Methods Twenty-one ULDH patients who were admitted between June 2019 and July 2021 and met the selection criteria were selected as the research subjects. There were 12 males and 9 females with an average age of 62.1 years (range, 55-72 years). The disease duration was 1-12 years (mean, 5.7 years). There was 1 case of L1, 2, 4 cases of L2, 3, and 16 cases of L3, 4. The CT myelography data of T12-S3 segment was saved in DICOM format and imported into Mimics21.0 software for three-dimensional reconstruction. The relationship between the intersection (point Q) of spinous process and the inferior margin of lamina, the indentation of superior margin of ligamentum flavum, the inferior margin of nerve root origin, intervertebral space, and foramen were observed. The Mimics21.0 software was used to create a 3-mm-diameter cylinder to simulate the UBE channel and measure its abduction angle (∠b1), as well as measure the following lumbar vertebra-related indicators: in L1,2-L3,4 segments, the vertical distance from the point Q to the inferior margin of the contralateral lumbar pedicle of the same lumbar vertebra (a1), the superior margin of the contralateral pedicle of the lower lumbar vertebra (a2), the lower endplate of the same lumbar vertebra (a3), the upper endplate of the lower lumbar vertebra (a4); the vertical distance from the lower endplate of lumbar vertebra to the inferior margin of the lumbar pedicle (c1), the vertical distance from the upper endplate of the lower lumbar vertebra to the superior margin of the lumbar pedicle (c2); the vertical distance from the inferior margin of the nerve root origin to the superior margin (d1) and the inferior margin (d2) of the lumbar pedicle, respectively; the vertical distance from the intersection (point P) of the indentation of superior margin of ligamentum flavum and the medial margin of the lumbar pedicle to the superior margin (e1) and the inferior margin (e2) of the lumbar pedicle, respectively; the horizontal distance from the lateral margin of the dural mater (f1) and the narrowest part of the lumbar isthmus (f2) to the facet joint space, respectively. Thirteen of the patients included in the study chose the UBE surgery via contralateral approach. There were 8 males and 5 females with an average age of 63.3 years (range, 55-71 years). The disease duration was 2-12 years, with an average of 6.2 years. There were 3 cases of L2, 3 and 10 cases of L3, 4. The perioperative complications and surgical decompression were recorded. And the effectiveness were evaluated by visual analogue scale (VAS) score, Oswestry disability index (ODI), and short form-36 health survey (SF-36) score. Results The imaging results showed that there was no significant difference in a1, a3, a4, e1, e2, f1, and f2 between segments (P>0.05), and there were significant differences (P<0.05) in a2 and c2 between L1, 2 and L3, 4 segments, in ∠b1 and d2 between L1, 2, L2, 3 segments and L3, 4 segments, and in c1 and d1 between L1, 2 and L2, 3, L3, 4 segments. The 87.30% (110/126) of point Q of L1, 2-L3, 4 segments corresponded to the inferior articular process, and 78.57% (99/126) of the lower endplate corresponded to the level of the isthmus. All 13 patients completed the UBE surgery via contralateral approach, and none were converted to open surgery. All patients were followed up 12-17 months (mean, 14.6) months. The VAS score of low back pain and leg pain, ODI, and SF-36 score at 6 and 12 months after operation significantly improved when compared with those before operation (P<0.05), and further improved at 12 months after operation when compared with 6 months after operation (P<0.05). The imaging review results showed that the herniated disc was removed and the dura mater was decompressed adequately. Conclusion The point Q, the superior margin of ligamentum flavum, and lumbar pedicle can be used as the markers for the treatment of ULBD with UBE surgery via contralateral approach, making the procedure safer, more precise, and more effective.
Objective To compare the effectiveness of posterolateral approach lumbar interbody fusion assisted by one-hole split endoscope (OSE) and traditional posterior lumbar interbody fusion (PLIF) in the treatment of L4, 5 degenerative lumbar spondylolisthesis (DLS). Methods The clinical data of 58 patients with DLS who met the selection criteria admitted between February 2020 and March 2022 were retrospectively analyzed, of which 26 were treated with OSE-assisted posterolateral approach lumbar interbody fusion (OSE group) and 32 were treated with PLIF (PLIF group). There was no significant difference between the two groups in terms of gender, age, body mass index, Meyerding grade, lower limb symptom side, decompression side, stenosis type, and preoperative low back pain visual analogue scale (VAS) score, leg pain VAS score, Oswestry disability index (ODI), and the height of the anterior and posterior margins of the intervertebral space (P>0.05). The operation time, intraoperative blood loss, postoperative hospital stay, and complications were compared between the two groups. The low back pain and leg pain VAS scores and ODI before operation, at 1 month, 6 months after operation, and last follow-up, the height of anterior and posterior margins of the intervertebral space before operation, at 6 months after operation, and last follow-up, the modified MacNab criteria at last follow-up after operation were used to evaluate the effectiveness; and the Bridwell method at last follow-up was used to evaluate the interbody fusion. Results Both groups successfully completed the operation. Compared with the PLIF group, the OSE group showed a decrease in intraoperative blood loss and postoperative hospital stay, but an increase in operation time, with significant differences (P<0.05). In the OSE group, no complication such as nerve root injury and thecal sac tear occurred; in the PLIF group, there were 1 case of thecal sac tear and 1 case of epidural hematoma, which were cured after conservative management. Both groups of patients were followed up 13-20 months with an average of 15.5 months. There was no complication such as loosening, sinking, or displacement of the fusion cage. The low back pain and leg pain VAS scores, ODI, and the height of anterior and posterior margins of the intervertebral space at each time point after operation in both groups were significantly improved when compared with those before operation (P<0.05). Except for the VAS score of lower back pain in the OSE group being significantly better than that in the PLIF group at 1 month after operation (P<0.05), there was no significant difference in all indicators between the two groups at all other time points (P>0.05). At last follow-up, both groups achieved bone fusion, and there was no significant difference in Bridwell interbody fusion and modified MacNab standard evaluation between the two groups (P>0.05). Conclusion OSE-assisted posterolateral approach lumbar interbody fusion for L4, 5 DLS, although the operation time is relatively long, but the postoperative hospitalization stay is short, the complications are few, the operation is safe and effective, and the early effectiveness is satisfactory.