Objective: The aim of this study was to compare the clinical and radiologic outcomes of 3 types of minimally invasive posterior cervical foraminotomy (PCF): uniportal endoscopic surgery, biportal endoscopic surgery, and microsurgery.Methods: Between January 2019 to January 2020, PCF was performed using 3 different approaches to treat foraminal stenosis. The foraminal expansion rate, facet resection rate, and surgical foraminal approach angle were measured using magnetic resonance imaging. Visual analogue scale (VAS) scores for neck and arm pain, neck disability index (NDI), MacNab criteria, operation time, hospital stay, and complications were assessed. Clinical and radiologic parameters were compared among the 3 surgical groups.Results: There were 38, 30, and 50 patients in the uniportal endoscopy, biportal endoscopy, and microscopy groups, respectively. Microscopy group displayed significantly higher foraminal expansion compared to uniportal endoscopy group (p = 0.001). Facet resection rates and inclination angle for facet joint undercutting were significantly different among the 3 groups. Uniportal endoscopy group had the highest inclination angle and the least facet resection. On the 6 months and final follow-up, VAS scores and NDI were significantly lower in the uniportal endoscopy group than in the microscopy group (p = 0.000).Conclusion: All 3 types of PCF displayed favorable clinical outcomes and sufficient expansion of the midforaminal area. Two endoscopy groups showed a significantly higher inclination angle for undercutting the facet joint and a lower facet resection rate than the microscopy group. Reduced facet joint resection using an inclinatory approach did not interfere with sufficient foraminal expansion and enhanced the clinical result after 6 months of follow-up.

Objective: Advanced biportal endoscopic surgery techniques can be used to treat thoracic myelopathy secondary to ossification of the ligamentum flavum (OLF). This case series elaborates on a feasible biportal endoscopic technique for thoracic OLF removal and evaluates clinical and radiological outcomes.Methods: A biportal endoscopic posterior thoracic laminectomy was performed to remove the thoracic OLF. Surgical techniques have evolved from inside-out piecemeal removal methods to outside-in en bloc removal methods. Preoperative computed tomography was performed to analyze dural ossification and OLF types. Intraoperative videos were reviewed to observe dural ossification and to determine the surgical method. Neurological outcomes were assessed using the Japanese Orthopaedic Association (JOA) score.Results: Clinical symptoms and neurological function improved markedly after surgery (JOA score, preoperative: 12.6 ± 1.0, final follow-up: 15.6 ± 1.2). The mean operation time per segment was not short (106.6 ± 38 minutes). At early experience stages, inside-out piecemeal decompression was used and it caused intraoperative spinal cord injury. However, outside-in en bloc decompression technique did not induce neural complications. Postoperative segmental instability and correlated mechanical back pain were not observed.Conclusion: The biportal endoscopic posterior thoracic approach is an attractive surgical option to treat thoracic spondylotic myelopathy secondary to OLF. Piecemeal inside-out decompression can induce irreversible spinal cord injury, especially in the early experience stages. Outside-in decompression is more efficient and safer than inside-out pattern procedures by minimizing dural manipulation. Nonetheless, this technique is technically demanding and should only be performed in selected patients after acquiring abundant experience with endoscopic spine surgeries.

Background: Multifocal intra-and-extraspinal lumbar stenotic lesions could be decompressed with one endoscopic surgical approach, which has the advantages of functional structure preservation, technical efficacy, and safety. Methods: A retrospective study was performed on 48 patients who underwent uniportal endoscopic contralateral approach due to coexisting lateral recess, foraminal, and extraforaminal stenosis at the L5-S1 level. Foraminal stenosis grade and postoperative dysesthesia (POD) were analyzed. Visual analog scale (VAS) pain scores, modified Oswestry Disability Index (ODI) scores, and MacNab criteria for evaluating pain disability and response were analyzed. Results: The foraminal stenosis grade of the treated spinal levels was grade 1 (n = 16, 33%), grade 2 (n = 20, 42%), and grade 3 (n = 12, 25%). The rate of occurrence of POD grade 2 and above, which may be related to intraoperative dorsal root ganglion (DRG) retraction injury, was revealed to be 4.2% (two with grade 2, none with grade 3). The patients showed favorable clinical outcomes. Conclusions: Uniportal endoscopic interlaminar contralateral approach is an effective procedure to resolve combined stenosis (lateral recess, foraminal, and extraforaminal region) with one surgical approach at the L5-S1 level. It may be a minimal DRG retracting and facet joint preserving procedure in foraminal and extraforaminal decompression.

Objective: We compared the midterm clinical and radiological outcomes between 2 types of full endoscopic posterior cervical foraminotomy, including conventional posterior endoscopic cervical foraminotomy (PECF) and modified inclined technique for PECF.Methods: One of the 2 types of PECF surgery was performed for defined cervical foraminal stenosis. The foraminal expansion ratio and facet resection rate and foraminal stenosis grade were measured using magnetic resonance imaging. Visual analogue scale (VAS) scores for neck and arm pain, neck disability index, MacNab criteria, operation time, hospital stay, and complications, including postoperative dysesthesia, were assessed. Clinical and radiological parameters were compared between the 2 surgical groups.Results: There were 49 and 46 patients in the PECF and modified-PECF groups, respectively. The modified-PECF group showed significantly higher expansion of distal foraminal diameter and foraminal height, and a lower facet resection rate compared to PECF group (in all, p < 0.001). The modified-PECF group displayed significantly lower VAS score for neck pain at 1 day and 1 week after surgery and lower arm pain VAS score after 6-month follow-up (p = 0.002, p = 0.001, p = 0.002, respectively).Conclusion: Compared with the PECF, the modified inclined technique has radiologic benefits, including enhanced facet joint preservation, restoration of the natural course of nerve roots, and prevention of restenosis by expanding the superior articular process base, especially in grade 2 foraminal stenosis. Furthermore, the modified inclined technique significantly improved the postoperative VAS score for neck pain within the 1-week follow-up and that of arm pain after 6-month follow-up.

Study Design: Retrospective comparative study. Objective: Assessment of difference in clinical and computer tomographic outcomes between the 2 cohorts. Methods: Computer tomographic evaluation by Bridwell’s grade, Kim’s stage, Kim’s subsidence grade and clinical evaluation by VAS, ODI and McNab’s criteria on both cohorts. Results: 33 levels of Endo-TLIF and 22 levels of TLIF were included, with a mean follow up of 14.3 (10-24) and 22.9 (13-30) months respectively. Both Endo-TLIF and TLIF achieved significant improvement of pain and ODI at post-operative 4 week, 3 months and at final follow up with VAS 4.39 ± 0.92, 5.27 ± 1.16 and 5.73 ± 1.21in Endo-TLIF and 4.55 ± 1.16, 5.05 ± 1.11 and 5.50 ± 1.20 in TLIF respectively and ODI at post-operative 1 week, 3 months and final follow up were 43.15 ± 6.57, 49.27 ± 8.24 and 51.73 ± 9.09 in Endo-TLIF and 41.73 ± 7.98, 46.18± 8.46 and 49.09 ± 8.98 in TLIF respectively, P < 0.05. Compared to TLIF, Endo-TLIF achieved better VAS with 0.727 ± 0.235 at 3 months and 0.727 ± 0.252 at final follow up and better ODI with 3.88 ± 1.50 at 3months and 3.42 ± 1.63 at final follow up, P < 0.05. At 6 months radiological evaluation comparison of the Endo-TLIF and TLIF showed significant with more favorable fusion rate in Endo-TLIF of −0.61 ± 0.12 at 6 months and −0.49 ± 0.12 at 1 year in Bridwell’s grading and 0.70 ± 0.15 at 6 months and 0.56 ± 0.14 at 1 year in Kim’s stage.There is less subsidence of 0.606 ± 0.18 at 6 months and −0.561 ± 0.20 at 1 year of Kim’s subsidence grade, P < 0.05. Conclusion: Application of single level uniportal endoscopic posterolateral lumbar interbody fusion achieved better clinical outcomes and fusion rate with less subsidence than microscopic minimally invasive transforaminal lumbar interbody fusion in mid-term evaluation for our cohorts of patients.