Full endoscopic techniques are becoming more popular for degenerative lumbar pathologies. Percutaneous endoscopic lumbar interbody fusion (PETLIF) is a minimally invasive surgical technique for spondylolisthesis and lumbar spinal canal stenosis with instability. Nagahama first introduced PETLIF in 2019. This study investigated the clinical outcomes and complications of 24 patients who underwent PETLIF in our facility and compared them with previous studies. Literature searches were conducted on PubMed and Web of Science. The PETLIF surgical technique involves three steps to acquire disc height under general anesthesia. The procedure includes bone harvesting, spondylolisthesis reduction, endoscopic foraminoplasty, disc height expansion using an oval dilator, and intervertebral disc curettage. A cage filled with autologous bone is inserted into the disc space and secured with posterior fixation. Patients underwent PETLIF with an average operation time of 130.8 min and a blood loss of 24.0 mL. Postoperative hospital stays were 9.5 days. Improvement in VAS, disc height, spinal canal area, and % slip was observed, while lumbar lordosis remained unchanged. Complications included end plate injury, subsidence, and exiting nerve root injury. The differences between PETLIF and the extracted literature were found in patients’ age, direct decompression, epidural or local anesthesia, approach, order of PPS, and cage insertion. In conclusion, PETLIF surgery is a practical, minimally invasive surgical technique for patients with lumbar degenerative diseases suffering from back and leg pain, demonstrating significant improvements in pain scores. However, it is essential to carefully consider the potential complications and continue to refine the surgical technique further to enhance the safety and efficacy of this procedure.

Lumbar spinal stenosis (LSS) causes disabling back and radicular pain. Full-endoscopic spine surgery offers minimally invasive decompression, but uniportal and biportal approaches have limitations. Assisted full-endoscopic spine surgery (AFESS) combines the advantages of both techniques to enhance decompression while preserving facet joints. Can AFESS provide effective decompression with high facet preservation for LSS, and what is the learning curve for this technique? We retrospectively reviewed 33 patients with single-level LSS treated with AFESS, divided into initial (20 cases) and advanced (13 cases) phases. Outcomes assessed at a minimum 6-month follow-up included operative time, facet joint preservation ratio, complications, and visual analog scale (VAS) scores for back and leg pain. Operative time decreased significantly from the initial to the advanced phase (mean 99 vs 72 min; p < 0.01). Facet joints were more preserved in the advanced phase (76.2 % vs 68.9 %, p < 0.05). In the initial and advanced phases, mean lumbar VAS improved from 4.2 to 1.1 cm and 2.8 to 0.2 cm, respectively. Radicular VAS improved from 7.7 to 0.8 cm (initial) and 6.9 to 0.9 cm (advanced) (p < 0.01 for all). Two patients (6 %) experienced minor complications in the initial phase, with no permanent deficits. AFESS is safe and effective, achieving adequate decompression with high facet preservation and significant pain relief in LSS patients. By integrating uniportal and biportal endoscopic approaches, AFESS overcomes limitations of each. The well-defined learning curve suggests it can be efficiently incorporated into clinical practice with minimal complications.

Endoscopic lumbar discectomy (ELD) is a key advancement in minimally invasive spinal surgery, particularly for lumbar disc herniation. Interlaminar endoscopic lumbar discectomy (IELD) and transforaminal endoscopic lumbar discectomy (TELD) are the two major methods used for FED. TELD, while less familiar to spine surgeons inexperienced in endoscopic surgery, presents challenges in visualizing the dura mater, a crucial aspect for reducing surgical complications. The hand down outside-in (HDOI) technique introduced by Dezawa enhances this visualization by positioning the cannula tip dorsally on the intervertebral disc and maneuvering it between the dura mater and disc to the spinal canal’s midpoint. The cannula is then flipped to directly visualize the dura mater, enabling safe removal of the prolapsed disc material. A comparative study involving 20 patients treated from April 2020 to April 2022 examined the efficacy of the HDOI technique against conventional TELD. Each group, comprising ten patients, underwent ELD for lumbar disc herniation. While both groups showed similar improvements in clinical outcomes, as assessed using the Japanese Orthopedic Association (JOA) score and visual analogue scale (VAS) for pain, the HDOI group exhibited a 100% success rate for dura mater visualization, and this rate is significantly higher than the 60% observed in the conventional TELD group. Additionally, the time required for dura mater visualization was notably shorter for the HDOI technique. These results indicate that the HDOI technique not only enhances the safety and efficacy of TELD but may also encourage its wider use in clinical settings.

We report a case of tibial condylar valgus osteotomy (TCVO) for ipsilateral knee osteoarthritis (OA) after hip arthrodesis. A 58-year-old woman developed right purulent hip arthritis at one month of age and underwent right hip fusion at 16 years old. She visited our department at the age of 57 because her right knee joint pain worsened. The range of motion for her right knee was 80 and -5 of flexion and extension, respectively, and she experienced medial weight-bearing pain. A plain X-ray image showed that the right knee joint had end-stage knee OA with a bone defect inside the tibia, and the tibial plateau shape was the pagoda type. There was a marked instability in her right knee with a valgus of 9 and varus of 7 on stress photography. She underwent TCVO on her right knee and was allowed full load four weeks after surgery. Computed tomography imaging showed bone union nine months after surgery. Two years after the operation, there was no correction loss, and she could walk independently without pain. In general, total knee arthroplasty (TKA) is indicated for end-stage knee OA; however, there are problems, such as early loosening due to the increased mechanical load on the knee after hip OA. In this case, since a good course was obtained, TCVO is considered a treatment option for terminal knee OA after hip arthrodesis.

Background/Objectives: The pyro-drive jet injector (Daicel Injector P1 SC) is a needle-free injection device which propels the medication in a fine jet at high pressure, penetrating the skin to deliver the medication subcutaneously. In this study, we evaluated the safety and efficacy of this jet injector for the administration of seasonal influenza vaccine. Methods: As an open-label and observational case-control study, we compared 30 participants who received the seasonal influenza vaccine (2025-2026) via conventional needle injection with 30 participants who received it via the jet injector to evaluate the immune responses and local and systemic adverse reactions. In 2025-2026 season, a trivalent influenza vaccine covering the A strains (H1N1 and H3N2), as well as the B/Victoria strain was administered. Antibody titers were assessed using hemagglutination inhibition (HI) assays 4 to 12 weeks after vaccination, and seroconversion rate (antibody titer ≥40-fold) was calculated. Results: Regarding the immune response, the seroconversion rates were high for the pyro-drive jet injector group (A/H1N1; 7% vs.37%, P=0.005; A/H3N2; 43% vs. 60%, P=0.196; B; 33% vs. 43%, P=0.426). Similarly, the mean geometric mean titer (GMT) was high with the pyro-drive jet injector (A/H1N1; 5.71 vs.18.68, P=0.001; A/H3N1 19.9 vs.40.63, P=0.042; B 12.42 vs.24.08, P=0.069). Regarding safety, there was no difference in the incidence of local reactions between the two groups with no serious adverse events. Conclusions: The pyro-drive jet injector could offer tolerability comparable to that of a conventional needle and have the potential to enhance immune response for the influenza vaccine.