Kang MS, et al. Clin Orthop Surg. 2022 Jul;14:e54. https://doi.org/10.4055/cios22050

Objective: Biportal endoscopic transforaminal lumbar interbody fusion (BE-TLIF) is an emerging, minimally invasive technique performed under biportal endoscopic guidance. However, concerns regarding cage subsidence and sufficient fusion during BE-TLIF necessitate careful selection of an appropriate interbody cage to improve surgical outcomes. This study compared the fusion rate, subsidence, and other radiographic parameters according to the material and size of the cages used in BE-TLIF.Methods: In this retrospective cohort study, patients who underwent single-segment BE-TLIF between April 2019 and February 2023 were divided into 3 groups: group A, regular-sized three-dimensionally (3D)-printed titanium cages; group B, regular-sized polyetheretherketone cages; and group C, large-sized 3D-printed titanium cages. Radiographic parameters, including lumbar lordosis, segmental lordosis, anterior and posterior disc heights, disc angle, and foraminal height, were measured before and after surgery. The fusion rate and severity of cage subsidence were compared between the groups.Results: No significant differences were noted in the demographic data or radiographic parameters between the groups. The fusion rate on 1-year postoperative computed tomography was comparable between the groups. The cage subsidence rate was significantly lower in group C than in group A (41.9% vs. 16.7%, p=0.044). The severity of cage subsidence was significantly lower in group C (0.93±0.83) than in groups A (2.20±1.84, p=0.004) and B (1.79±1.47, p=0.048).Conclusion: Cage materials did not affect the 1-year postoperative outcomes of BE-TLIF; however, subsidence was markedly reduced in large cages. Larger cages may provide more stable postoperative segments.

Objective: To compare the safety profiles of biportal endoscopic spinal surgery (BESS) and microscopic spinal surgery (MSS) for lumbar disc herniation and spinal stenosis by analyzing the associated adverse events.Methods: We pooled data from 2 prospective randomized controlled trials involving 220 patients (110 in each group) who underwent single-level lumbar surgery. Participants aged 20–80 years with radiating pain due to lumbar disc herniation or spinal stenosis were included in this study. Adverse events were recorded and analyzed over a 12-month follow-up period.Results: The overall adverse event rates were 9.1% (10 of 110) in the BESS group and 17.3% (19 of 110) in the MSS group, which were not statistically significantly different (p=0.133). Notably, wound dehiscence occurred in 8.2% of MSS cases but in none of the BESS cases. Both groups showed similarly low rates of complications, such as dural tears, epidural hematoma, and nerve root injury. The most common adverse event in the BESS group was recurrent disc herniation (2.7%), whereas that in the MSS group was wound dehiscence (8.2%).Conclusion: BESS demonstrated a safety profile comparable to that of MSS for the treatment of lumbar disc herniation and spinal stenosis, with a trend towards fewer overall complications. BESS offers particular advantages in terms of reducing wound-related complications. These findings suggest that BESS is a safe alternative to conventional MSS and potentially offers the benefits of a minimally invasive approach without compromising patient safety.

Study Design: Retrospective study. Objective: To compare the clinical outcomes of the biportal endoscopic technique for primary lumbar discectomy (BE-LD) and revision lumbar discectomy (BE-RLD). Methods: Eighty-one consecutive patients who underwent BE-LD or BE-RLD, and could be followed up for at least 12 months were divided into two groups: Group A (BE-LD; n = 59) and Group B (BE-RLD; n = 22). Clinical outcomes included the visual analog scale (VAS), Oswestry Disability Index (ODI), and modified MacNab’s criteria. Perioperative results included operation time (OT), length of hospital stay (LOS), amount of surgical drain, and kinetics of serum creatine phosphokinase (CPK) and C-reactive protein (CRP). Clinical and perioperative outcomes were assessed preoperatively and postoperatively at 2 days and at 3, 6, and 12 months. Postoperative complications were noted. Results: Both groups showed significant improvement in pain (VAS) and disability (ODI) compared to baseline values at postoperative day 2, which lasted until the final follow-up. There were no significant differences in the improvement of the VAS and ODI scores between the groups. According to the modified MacNab’s criteria, 88.1 and 90.9% of the patients were excellent or good in groups A and B, respectively. OT, LOS, amount of surgical drain, and kinetics in serum CRP and CPK levels were comparable. Complications in Group A included incidental durotomy (n = 2), epidural hematoma (n = 1), and local recurrence (n = 1) and in Group B incidental durotomy (n = 1) and epidural hematoma (n = 1). Conclusion: BE-RLD showed favorable clinical outcomes, less postoperative pain, and early laboratory recovery equivalent to BE-LD.

Background: Lumbar spinal stenosis (LSS) impairs quality of life and is commonly treated with microscopic laminectomy. Some have suggested that biportal endoscopic laminectomy may offer advantages through smaller incisions and reduced tissue trauma. However, it remains unclear whether these theoretical advantages translate into meaningful differences in patient-reported outcomes that patients would actually perceive. Questions/purposes: We performed an RCT in which we asked: (1) Does biportal endoscopic laminectomy result in equivalent functional outcomes as measured by the Oswestry Disability Index (ODI) at 1 year compared with microscopic laminectomy? (2) Are pain relief, quality of life measures, and surgery-related outcomes similar between biportal endoscopic laminectomy and microscopic laminectomy? (3) Are adverse event rates comparable between the two surgical techniques? Methods: We conducted an assessor-blind RCT at six centers in South Korea. Between July 19, 2021, and April 6, 2023, a total of 120 patients with LSS were randomized to undergo biportal endoscopic laminectomy (n = 60) or microscopic laminectomy (n = 60). At 1 year, 90% (54 of 60) of patients in the biportal endoscopic laminectomy group and 86.7% (52 of 60) of patients in the microscopic laminectomy group were accounted for and fully analyzed. No crossover occurred between treatment groups, and the primary analysis followed a modified intention-to-treat approach. The baseline characteristics were well balanced between the two groups. The primary outcome was the ODI score at 12 months postoperatively. Secondary outcomes included VAS pain scores, quality of life, perioperative parameters, and adverse events, assessed at baseline, 2 weeks, and at 3, 6, and 12 months. This was an equivalence trial using the ODI as the primary outcome for sample size calculation, with an equivalence margin of ± 12.8 points, which represents the minimum clinically important difference for the ODI. Results: In the modified intention-to-treat analysis, we found no difference between the biportal endoscopic laminectomy and microscopic laminectomy groups in terms of ODI scores at 12 months (13 ± 12 versus 18 ± 18, mean difference -5 points [95% confidence interval -10 to 1]; p = 0.12), demonstrating equivalence between the techniques. Secondary outcomes including VAS pain scores, quality of life measures, functional recovery, satisfaction, surgical variables, and radiographic parameters were also similar between groups, with no clinically important differences observed. Adverse events were similar between biportal endoscopic laminectomy and microscopic laminectomy. Conclusion: This study found biportal endoscopic laminectomy to be equivalent to microscopic laminectomy in functional outcomes at 12 months. However, the observed differences do not represent clinically meaningful benefits that patients would perceive. Until high-quality evidence demonstrates patient-important advantages, we recommend against the wide adoption of this technique in clinical practice. Level of Evidence: Level I, therapeutic study.