From the Editor-in-Chief: Featured Articles in the December 2024 Issue

Objective To identify the risk factors for proximal junctional failure (PJF) after adult spinal deformity (ASD) surgery despite ideal sagittal correction according to age-adjusted alignment target. Methods The study included patients who underwent low thoracic to pelvic fusion for ASD and obtained ideal correction according to age-adjusted pelvic incidence minus lumbar lordosis. PJF was defined either radiographically as a proximal junctional angle (PJA) of >28° plus a difference in PJA of >22° or clinically as revision surgery for proximal junctional complications. Clinical and radiographic variables were assessed to identify the risk factors for PJF. Results The final study cohort consisted of 196 patients, of whom 170 were women (86.7%), with an average age of 68.3 years. During mean follow-up duration of 45.9 months, PJF occurred in 43 patients (21.9%). Multivariate logistic regression analysis revealed that old age (odds ratio [OR], 1.063; 95% confidence interval [CI], 1.001–1.129; p=0.046), large preoperative sagittal vertical axis (OR, 1.007; 95% CI, 1.001–1.013; p=0.024), nonuse of a transverse process (TP) hook (OR, 5.556; 95% CI, 1.205–19.621; p=0.028), and high lumbar distribution index (LDI) (OR, 1.136; 95% CI, 1.109–1.164; p<0.001) were significant risk factors for PJF development. Conclusion A sizeable proportion of patients (21.9%) developed PJF despite achieving ideal sagittal correction. Using TP hooks with avoiding excessive LDI can be helpful to further mitigate the risk of PJF development in this patient group.

Objective To analyze the predictive factors for neck pain and cervical spine function after laminoplasty for degenerative cervical myelopathy (DCM) using K-means for longitudinal data (KML). Methods In this prospective cohort study, we collected clinical and radiographic data from patients with DCM who underwent cervical laminoplasty. A novel index of surgical outcome, “neck function,” which comprises neck pain and cervical spine function according to the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire, was proposed. We treated surgical outcomes as longitudinal rather than cross-sectional data and used KML for analysis. Patients were categorized as having good or poor outcomes based on the KML graph of neck pain and cervical spine function. Results From 2016 to 2020, 104 patients underwent laminoplasty for DCM; however, 35 patients were excluded because of loss to follow-up or incomplete data. The authors found that central canal stenosis (odds ratio [OR], 17.93; 95% confidence interval [CI], 1.26–254.73; p=0.03) and preoperative neck pain (OR per 1 point increase=1.49; 95% CI, 1.12–1.99; p=0.006) were 2 negative predictive factors and that a positive K-line during flexion was a positive predictive factor (OR, 0.11; 95% CI, 0.01–0.87; p=0.036) for neck function after laminoplasty. Conclusion Central canal stenosis, preoperative neck pain and a K-line during flexion were found to be predictive of postoperative neck pain and cervical spine function after laminoplasty. To achieve better surgical outcomes for neck function, the authors suggest the utilization of these determinants as a guiding framework for the selection of surgical approaches for DCM.

Endoscopic spinal surgery has gained increasing popularity over the past 10 years. Its muscle-preserving nature, reduction in postoperative pain, and lower complication rates have contributed to the growing number of surgeons adopting this technique year after year. This same progression has led to the application of the technique in oncological pathology, primarily for separation surgeries and biopsies of extradural lesions. However, reports in the literature on the use of this technique to treat intradural spinal tumors remain scarce. To present a case report of a patient with an intradural lesion, compatible with schwannoma, successfully removed using a fully endoscopic technique. A 46-year-old female patient presented with a long-standing history of low back pain and bilateral leg pain. The pain worsened over the past few months before her initial presentation. She also reported experiencing weakness in her feet and intermittent hypesthesia in her legs. Magnetic resonance imaging (MRI) showed a small intradural extramedullary tumor at the L1 level. Given the patient’s young age, the tumor location at the thoracolumbar junction, and the rather small tumor size, a full-endoscopic approach was selected and performed. A step-by-step video of the surgical technique is provided with the manuscript. The current follow-up period is 2.5 years, with the patient remaining asymptomatic. The most recent follow-up MRI, conducted 16 months after the surgery, indicated no signs of recurrence. To our knowledge, this is the first video report providing a step-by-step description of this procedure. More high-quality evidence is needed to properly evaluate the safety and outcomes of this technique.