Objective: Perioperative hypothermia can lead to various complications. Although various warming techniques have been used to prevent perioperative hypothermia, the effect of these techniques on surgical site infection (SSI) during posterior fusion surgery is unclear. The effects of warming devices on SSI rates were therefore analyzed using data complied by the Health Insurance and Review Assessment (HIRA) Service in Korea.Methods: This study included 5,406 patients in the HIRA Service database who underwent posterior fusion surgery during the years 2014, 2015, and 2017. Factors related to SSI in these patients, including warming devices, antibiotics, and transfusion, were analyzed.Results: The incidence of SSI was higher in patients who underwent forced air warming than in those who did not undergo active warming (odds ratio [OR], 1.73; p = 0.039), especially above 70 years old (OR, 4.11; p = 0.014). By contrast, the incidence of SSI was not significantly higher in patients who underwent device using conduction. Infection rates were higher in patients who received prophylactic antibiotics within 20 minutes before incision, than within 21 to 60 minutes (OR, 2.07; p = 0.001) and who received more blood transfusions (1 pint < volume ≤ 2 pint; OR, 1.75; p = 0.008, > 2 pint; OR, 2.73; p = 0.004).Conclusion: SSI rates were higher in patients who underwent warming with forced air devices than with devices using conduction, as well as being higher in patients who older age, received blood transfusions and administered antibiotics within 20 minutes before incision. Devices using conduction have more advantages in preventing SSI than forced air warming device. In addition, the reduction of other risk factors for SSI may improve postoperative results.

Background/Objectives: This study aimed to identify risk factors associated with mechanical failure in patients undergoing spinal instrumentation without fusion for metastatic spinal tumors. Methods: We retrospectively evaluated data from 220 patients with spinal tumors who underwent instrumentation without fusion. Propensity scores were used to match preoperative variables, resulting in the inclusion of 24 patients in the failure group (F group) and 72 in the non-failure group (non-F group). Demographic, surgical, and radiological characteristics were compared between the two groups. Logistic regression and Kaplan–Meier survival analyses were conducted to identify predictors of mechanical failure. Results: Propensity score matching resulted in a balanced distribution of covariates. Lower Hounsfield unit (HU) values at the lowest instrumented vertebra (LIV) were the only independent predictor of implant failure (p = 0.037). A cutoff value of 127.273 HUs was determined to predict mechanical failure, with a sensitivity of 59.1%, specificity of 73.4%, and area under the curve of 0.655 (95% confidence interval: 0.49–0.79). A significant difference in survival was observed between the groups with HU values above and below the cutoff (p = 0.0057). Cement-augmented screws were underutilized, with an average of only 0.2 screws per patient in the F group. Conclusions: Preoperative LIV HU values < 127.273 were strongly associated with an increased risk of mechanical failure following spinal instrumentation without fusion. Alternative surgical strategies including the use of cement-augmented screws are recommended for patients with low HU values.

Background: Oblique lumbar interbody fusion (OLIF) is a minimally invasive technique used to manage degenerative lumbar conditions. The presence of vacuum phenomenon (VP) and associated endplate sclerosis may increase the risk of cage subsidence. This study evaluated the relationship between VP grade, endplate sclerosis, and subsidence in OLIF. Methods: This retrospective cohort study included 165 patients who underwent a single-level OLIF for lumbar stenosis. Patients were stratified into VP grades (0–3) based on preoperative computed tomography scans. Disc height, endplate sclerosis, and cage subsidence were radiologically assessed. Clinical outcomes, including back and leg pain visual analog scale, Oswestry Disability Index, and EuroQol-5 Dimension, were measured preoperatively and at follow-up. Results: High VP grades were associated with low preoperative disc height and increased endplate sclerosis. Although no significant differences in clinical outcomes or final fusion rates across VP grades were observed, the subsidence rate increased with VP grade, with a significant difference between VP grades 1 and 2 (p = 0.045) and between VP grades 2 and 3 (p = 0.032), indicating that subsidence rates increased as the VP grade advanced. Conclusions: High VP grades, particularly grades 2 and 3, may increase the risk of cage subsidence following OLIF. Therefore, VP grading may be worth considering during surgical planning to reduce the subsidence risk and improve outcomes.

Background and Objectives: Posterior cervical foraminotomy (PCF) aims to resolve cervical radiculopathy while preserving range of motion (ROM). However, its effectiveness in maintaining ROM is uncertain. This study investigates the changes in ROM after PCF and identifies preoperative factors that influence ROM reduction post surgery. Materials and Methods: This retrospective cohort study included patients treated at our hospital from August 2016 to September 2021. Clinical outcomes were assessed using the visual analog scale (VAS) for neck and arm pain and the neck disability index (NDI). Radiological outcomes included the segmental angle (SA), cervical angle (CA), C2–C7 SVA, Pfirrmann grade, extent of facetectomy, foraminal stenosis, and ROM. Patients were categorized into two groups based on segmental ROM changes: decreased (Group D) and maintained (Group M). Radiological and clinical outcomes were compared between the groups. Univariate and multivariate regression analyses were performed to identify risk factors for ROM loss after PCF. Results: 76 patients were included: 34 in Group D and 42 in Group M, with no demographic differences. Preoperatively, Group D had significantly larger flexion segmental and cervical angles than Group M (segmental, p < 0.001; cervical, p = 0.001). Group D also had a higher Pfirrmann grade (p = 0.014) and more bony bridge formations (p = 0.004). While no significant differences were observed in arm pain VAS and NDI scores, Group D exhibited worse neck pain VAS at the last follow-up (p = 0.03). Univariate linear regression indicated that preoperative segmental ROM (p < 0.001, B = 0.82) and bony bridge formation (p = 0.046, B = 5.33) were significant predictors of ROM loss post PCF. Conclusions: Patients with higher preoperative flexion angles and Pfirrmann grades at the operative level are at an increased risk for ROM loss and neck pain and often exhibit bony bridge formation. Accounting for these factors can improve surgical planning and patient outcomes.

Study Design: Technical note and case series. Objectives: We describe an indirect posterior decompression technique using plate gliding during anterior cervical discectomy and fusion (ACDF) in cervical myelopathy patients with an accompanying posterior pathology. Summary of Background Data: ACDF can effectively address an anterior pathology, that is, directly causing cord compression. However, a concurrent posterior pathology, such as hypertrophy or buckling of the ligamentum flavum, is challenging to resolve. Furthermore, occasional worsening of cord compression after ACDF due to aggravation via a posterior pathology may occur. Materials and Methods: We reviewed 6 patients with cervical myelopathy who underwent the plate gliding technique during ACDF in 2023. We assessed radiologic factors, including cord compression from the ligamentum flavum (CCLF) grade and segmental lordosis, before and after surgery. In addition, we evaluated the Japanese Orthopedic Association (JOA) scores preoperatively and 3 months postoperatively. Results: A postoperative improvement in CCLF grade was observed in all patients alongside a decrease in segmental lordosis. The average recovery rate indicated by the JOA scores at 3 months postoperatively was 65.3%. Conclusions: An indirect decompression technique using plate gliding during ACDF is beneficial for cervical myelopathy patients accompanied by posterior pathologies such as ligamentum flavum hypertrophy or buckling.