Purpose: Spinal fusion, which is considered the standard treatment for segmental instability, carries an inherent risk of irreversible loss of spinal flexibility and the subsequent development of adjacent segment disease. Spinal dynamic stabilization has emerged as a motion-preserving alternative intended to mitigate these limitations. This study retrospectively compared clinical and radiological outcomes between the Spine Gold (SG) system and decompression alone in patients with single-level central stenosis accompanied by grade 1 spondylolisthesis. Methods: A total of 262 patients who underwent surgery between January 2013 and May 2024 were included in the analysis (SG fixation, n=161; decompression alone, n=101). All decompression procedures were performed using the unilateral laminectomy for bilateral decompression technique. Clinical outcomes were evaluated based on reoperation rates, time to reoperation, preoperative and 1-month postoperative visual analogue scale scores for back pain and radicular pain, and 1-month postoperative MacNab criteria. Radiological outcomes, including static slippage and dynamic instability at both the index and proximal adjacent levels, were assessed using preoperative radiographs and radiographs obtained at final follow-up. Results: Both treatment groups demonstrated significant postoperative improvement in pain outcomes. SG fixation was associated with significant reductions in static slippage and dynamic instability at the index level, along with a reduction in dynamic instability at the proximal adjacent level. In contrast, decompression alone resulted in postoperative increases in both static slippage and dynamic instability. The SG group also exhibited a significantly lower reoperation rate (10.6%) and a longer time to reoperation compared with the decompression-alone group (21.8%). All reoperations in the SG group occurred exclusively at the adjacent level, whereas reoperations in the decompression-alone group primarily involved recurrence or progression at the index level. Conclusion Dynamic stabilization using the SG system effectively stabilizes the index level while providing concomitant stabilization of the proximal segment. In carefully selected patients with single-level central stenosis and grade 1 spondylolisthesis, this approach may represent a viable alternative to fusion by offering improved long-term stability and lower reoperation rates, primarily through limiting progressive index-level instability compared with decompression alone.

Objective: To compare 1-year radiographic and clinical outcomes between expandable cages and polyetheretherketone (PEEK) cages in patients undergoing endoscopic transforaminal lumbar interbody fusion (TLIF). Methods: This retrospective, single-surgeon cohort study included 84 patients (32 expandable cage, 52 PEEK cage) with at least 1 year of radiographic and clinical follow-up. Radiographic parameters included disc height, foraminal height, segmental lordosis, subsidence, cage length, and the cage-to-vertebral body area ratio measured on computed tomography. Clinical outcomes were evaluated using Numerical Rating Scale (NRS) scores and Bridwell fusion grading. Group comparisons were performed using t-tests and chi-square tests, and multivariate regression analyses were conducted to identify independent predictors of subsidence and fusion. Results: PEEK cages demonstrated greater correction of segmental lordosis (2.6° vs -0.3°, p=0.003) and significantly lower total subsidence (2.2±1.7 mm vs. 4.6±2.4 mm, p=0.001) compared with expandable cages. In contrast, expandable cages were associated with significantly greater improvement in back pain at 1 year (β=1.71 NRS points, p=0.014). A larger cage-to-vertebral body area ratio independently reduced the risk of severe subsidence ≥5 mm (odds ratio, 0.34 per 0.1 increase; p=0.033). Fusion outcomes, defined as Bridwell grades 1–2, did not differ significantly between the 2 groups. Conclusion Expandable cages provided greater back pain relief despite a higher degree of subsidence, whereas PEEK cages offered superior radiographic stability. These findings highlight important radiographic-clinical trade-offs in cage selection for endoscopic TLIF and support individualized decision-making based on patient anatomy, alignment objectives, and symptom profile.

The large working channel (LWC) uniportal endoscope offers significant advantages over the traditional unilateral biportal endoscopy for obese patients at lower lumbar levels. The LWC features a broader working channel (diameter > 5.5 mm) that accommodates larger surgical instruments, enhancing its ability to perform complex procedures with greater precision and efficiency. This expanded channel reduces the need for multiple incisions, minimizes surgical trauma, provides clear vision due to good water outflow channels, and increases surgical precision, which is particularly beneficial in patients with obesity who may have more challenging anatomy and an increased risk of complications. The improved instrument mechanism of LWC and enhanced visibility also enable better access and navigation within the restricted operative field, leading to more effective and less invasive interventions in patients with obesity. Overall, the design addresses the specific challenges of obesity, making it a superior choice for endoscopic procedures in this patient population at lower lumbar levels (L4–5 and L5–S1).

Lumbar spinal stenosis (LSS) is a significant complication of achondroplasia, often requiring surgical intervention. Traditional open decompression has been the standard treatment, but minimally invasive techniques, such as endoscopic unilateral laminotomy for bilateral decompression (ULBD), offer advantages in select cases. This case report describes a 48-year-old man with achondroplasia who presented with severe neurogenic claudication and lower extremity weakness due to multilevel LSS. A staged endoscopic ULBD approach was performed, initially addressing L2–3 and L4–5, followed by the remaining levels one week later. During the second operation, a delayed dural tear was discovered at the previously operated L2–3 level and successfully managed with a dural sealing matrix. Postoperatively, the patient demonstrated significant pain relief and functional improvement. This case highlights the feasibility and benefits of staged endoscopic ULBD in achondroplasia patients with multilevel LSS, as it enabled effective decompression while minimizing structural disruption.

Patients with degenerative lumbar spinal stenosis and double crush syndrome often require decompression of the nerve root at multiple levels. Traditional approaches are limited by the need for extensive bony resection and the risk of iatrogenic instability. The endoscopic contralateral approach offers a minimally invasive alternative, but has primarily been applied to single-level decompressions. This study evaluated the feasibility of an "extended" biportal endoscopic contralateral approach for 2-level decompression in a patient with double crush syndrome, detailing the surgical technique and outcomes. A 69-year-old female patient presented with bilateral leg pain and numbness attributed to severe stenosis at L4–5 and L5–S1. The patient underwent a single biportal endoscopic procedure utilizing an extended contralateral approach to decompress the L4–5 central canal, lateral recess, and the L5–S1 foramen. The technique involved careful planning of incision placement, sublaminar drilling, and decompression of the L5 nerve root across both levels. The second illustrative case is a patient with L4 double crush syndrome who was managed similarly. Postoperative imaging demonstrated successful decompression of the L4–5 central canal and L5–S1 foramen, with preservation of the L5 pars interarticularis. The patient experienced complete symptom resolution. The approach resulted in minimal soft tissue dissection and bony preservation, enhancing surgical efficiency. The extended biportal endoscopic contralateral approach effectively addresses double crush root syndrome through a single minimally invasive approach. This technique improves operating room efficiency, while still achieving good neural decompression without causing iatrogenic instability, and may be a viable surgical option for selected cases.

The introduction of endoscopic spine surgery has led to a paradigm shift in the treatment of spinal disorders. In particular, biportal endoscopic surgery has gained traction for its wider visual field and improved the maneuverability of instruments, familiar anatomy, and costeffectiveness. In this study, we describe our en bloc removal of the ligamentum flavum using a “butterfly” technique. This approach had several advantages: (1) The flavum serves as a protective barrier for the dura during drilling. (2) There is less epidural bleeding, which provides (3) better visualization. (4) In an inadvertent durotomy, this usually occurs later in the procedure, which is more manageable than the early stages of decompression. Biportal decompression for spinal stenosis can be performed using an en bloc ligamentum flavum removal technique that is safe, reproducible, and efficient. A systematic approach will help early adopters overcome the steep learning curve.

Ossification of the ligamentum flavum (OLF) in the thoracic spine is a cause of thoracic myelopathy that is more commonly found in East Asian populations (Koreans, Japanese, Chinese) than in others. Early diagnosis and sufficient surgical decompression can improve the functional prognosis for thoracic OLF. Surgical decompression is necessary and should be done as soon as the symptoms develop. There is a wide range of possible treatments, from standard open laminectomy to endoscopic decompression surgery. This video demonstrates the least invasive technique of decompressive laminectomy with bilateral decompression and removal of thoracic OLF through unilateral biportal endoscopic spinal surgery. The authors present the case of an 81-year-old male patient who presented with bilateral lower extremity weakness, numbness, pain, and ataxia. Magnetic resonance imaging and computed tomography scans of the whole spine showed the presence of OLF with severe spinal canal stenosis and a cord signal change at the T9–10 level. He underwent biportal endoscopic decompression and removal of thoracic OLF at T9–10. On the discharge day (postoperative day 7), motor power and pain had significantly improved. He could stand and independently ambulate with a walker.

Background: The importance of animal welfare is being recognized worldwide. Recently, the increasing demand for enhanced laboratory animal welfare has led to clinically featured transformations of animal research institutes. This study aims to describe the process and findings of veterinary medical check-ups and its influence on laboratory dogs and pigs welfare. Regular medical checkups were conducted by the attending veterinarian twice a year to ensure the health and welfare of dogs and pigs in our animal research institute. Based on the findings from the medi‑ cal checkup, we assessed the current health of dogs and pigs,providing reasonable treatments to prevent the risk of complications. Results: Blood tests and physical examinations revealed clinically relevant findings. Some of these findings were due to insufficient postoperative care after invasive surgical experiments and the remaining were predictable side effects after surgical experiments. However, one finding involved severe gum bleeding due to retained deciduous teeth.This animal was euthanized because it was judged to reach the humane endpoint. Majority of the dogs and pigs at our animal research institute were considered to be healthy, based on the comprehensive results of the medical checkups. Conclusions Regular medical checkups by the attending veterinarian established enhanced animal welfare, ensur‑ ing the accuracy and reproducibility of animal studies. This pioneering veterinary animal care program can serve as a potential advanced guideline for animal research institutes to improve dogs and pigs welfare.

Background and Objectives: This study aimed to evaluate the voice of patients with vocal cord palsy using the Praat compared to Speech tool.Materials and Method The medical record of the patients with vocal cord palsy from 2013 to 2021 was analyzed retrospectively to validate Praat as a voice evaluation modality compared to the speech tool. Total 60 patients were enrolled in this study. Thirty control and 30 vocal cord palsy patients were selected to undergo recording of voice samples. The voice samples, /a/ and “Sancheck” were evaluated both groups and cepstral peak prominence was analyzed with both modalities; Praat and speech tool. Results: Statistically significant differences were observed between the control and vocal cord palsy groups in the speech tool and Praat. There was also a significant difference between pre- and post-treatment values in the vocal cord palsy group. A similar change in the voice value was observed using both methods. The Praat showed a lower value in 1st visit of patients with vocal cord palsy in the vowel test. The Praat vowel test may sensitively represent voice problems in patients with vocal cord palsy. This could contribute to decision-making regarding the treatment modality for vocal cord palsy. Conclusion Praat is open-access software that is freely available. It can be easily and sufficiently used for voice evaluation in patients with vocal cord palsy.

Objectives: . The aim of this study was to compare the long-term oncologic outcomes of sentinel lymph node biopsy (SLNB) versus elective neck dissection (END) in clinically node-negative (cN0) tongue cancer. Methods: . This was a retrospective cohort study of patients with cN0 tongue cancer from a single institution, including 91 patients in the SLNB group and 120 patients in the END group. Results: . The overall recurrence rate showed no significant difference between the two groups. The regional control rate was also comparable between the two groups (P=0.490). The 5-year recurrence-free survival (RFS) was slightly better in the SLNB group than in the END group (P=0.427). The 5-year overall survival (OS) rate was 89.9% in the SLNB group versus 91.9% in the END group (P=0.737). In a propensity-matched subgroup analysis, the type of neck management did not affect RFS or OS. Conclusion . SLNB showed non-inferior oncologic outcomes compared to END in patients with cN0 tongue squamous cell carcinoma.