Spine Surgery and Related Research最新文献

Introduction: Anterior cervical discectomy and fusion (ACDF) is a common procedure for cervical degenerative disc disease, with a growing shift toward outpatient surgery. Despite advancements enabling shorter hospital stays, same-day discharge remains a complex decision influenced by factors such as case timing and surgeon-specific practices. This study aims to identify patient and operational factors associated with same-day discharge following ACDF.

Methods: We retrospectively analyzed all elective ACDF procedures performed by 24 different surgeons across 3 affiliated hospitals within a large urban health system between January 2021 and December 2022. Patient and clinical factors, case timing, and surgeon-specific practices were compared between patients who received same-day discharge and those who were admitted on the same day following ACDF.

Results: Among the 530 elective ACDF procedures analyzed, 18.5% resulted in same-day discharge. Same-day discharge occurred significantly more frequently in procedures involving fewer operative levels, no surgical drain, and lower estimated blood loss (EBL). In contrast, factors such as age, Charlson Comorbidity Index, American Society of Anesthesiologists score, and preoperative antiplatelet or anticoagulation use did not significantly impact discharge rates. Earlier case completion times were strongly associated with same-day discharge, with 69.4% of such discharges occurring in cases completed before 14:00. Surgeon preference emerged as a key determinant, with the 15 surgeons who performed 10 or more procedures falling into 3 distinct categories: those who never, rarely, or routinely discharged patients on the same day.

Conclusions: Surgeon preference plays a critical role in shaping discharge decisions following ACDF. Alongside case complexity, EBL, drain usage, and timing, surgeon preference strongly influences whether a patient is discharged on the same day. Identifying and understanding the concerns underlying variable surgeon practice patterns will help promote standardization of discharge criteria, optimize selection for same-day discharge, and improve healthcare resource utilization.

Introduction: High rates of postoperative rod fracture at the lumbosacral junction have been reported after long spinopelvic fixation. In the prevention of rod fractures, supplemental accessory rods (ARs) and lateral interbody fusion are commonly used and reportedly effective. However, the optimal AR placement to mitigate rod stress at the lumbosacral junction is unclear. We therefore used a synthetic bone model and a finite element model concurrently to address their respective shortcomings.

Methods: Both models included the lumbar spine (L1-L5) and the pelvis, and were instrumented with a screw and rod system and lateral interbody fusion cages to closely resemble actual surgical procedures. The four different constructs were: two primary rods (PRs) without ARs, PRs+contoured long ARs, PRs+short ARs, and PRs+straight long ARs. In our synthetic model, we applied vertical load to the constructs and measured rod strain at L5-S1 using strain gauges. We calculated a mean value of the five rods in each construct. In our finite element model, we measured maximum principal stresses at L5-S1 after the application of flexion/extension, lateral bending, and axial rotation loads.

Results: In our synthetic bone model, there was significant reduction of rod strain by 52% in PRs+straight long ARs compared with PRs without ARs (p=0.023). A reduction of average principal stress in the finite element model was observed in PRs+straight long ARs by up to 44.2% (highest against flexion load) compared with PRs without ARs.

Conclusions: We conducted concurrent biomechanical analyses using a synthetic bone model and a finite element model. We recommend straight long ARs to prevent rod fracture at the lumbosacral junction in long spinopelvic fixation.

Background: Spinal deformities occur in 10 to 77% of neurofibromatosis type 1 (NF1) cases. The dystrophic type of NF1 progresses rapidly and can cause severe neurological complications if left untreated. Surgical intervention is necessary, as bracing is ineffective. Although the joint anterior-posterior (AP) approach provides better correction than single approaches, it carries higher surgical risks, leading to an ongoing debate about optimal treatment strategies.

Methods: A systematic search was conducted across the Scopus, Embase, PubMed, and Google Scholar databases from inception to June 2024. Data on clinical characteristics, treatment approaches, radiological and functional outcomes, and complications were systematically collected and synthesized in a narrative format.

Results: Six studies involving 124 patients were analyzed, comprising five case series and one retrospective observational study. The AP approach showed better correction outcomes than the anterior-only (AO) and posterior-only approaches. All surgical approaches resulted in significant functional improvements, as reflected by increased Japanese Orthopaedic Association/modified Japanese Orthopaedic Association scores, decreased Visual Analog Scale scores, and reduced Neck Disability Index scores. However, the AP approach was associated with a higher incidence of complications, while the AO approach had the lowest incidence.

Conclusions: Existing evidence demonstrates that the AP approach leads to a better degree of correction than the AO or posterior-only approaches, despite higher complication rates. The dual mechanism of anterior reconstruction and posterior stabilization effectively addresses the challenges associated with dystrophic cervical kyphosis in patients with NF1.

Introduction: Low back pain (LBP) is a leading cause of disability worldwide, particularly in aging populations. While the Oswestry Disability Index (ODI) is widely used to assess LBP-related disability, few studies have evaluated its long-term trajectory and predictive factors in general populations.

Methods: This 7-year longitudinal study included 553 community-dwelling adults (mean age 66.3 years) from the Wakayama Spine Study, a population-based sub-cohort of the Research on Osteoarthritis/Osteoporosis against Disability (ROAD) study. Participants completed whole-spine magnetic resonance imaging and responded to the ODI questionnaire at baseline and follow-up. Disability levels were classified as mild (0%-20%), moderate (21%-40%), or severe (41%-60%). Longitudinal transitions in disability categories were analyzed descriptively. Multiple linear regression was used to identify predictors of ODI deterioration.

Results: The mean ODI score significantly increased from 9.6±11.5 at baseline to 12.2±14.2 after 7 years (p<0.001), although the change did not reach clinical significance. Among participants initially classified as mildly disabled (n=468), 88.0% remained stable, while 12.0% worsened. Of those with moderate disability (n=73), 35.6% improved, 44.0% remained unchanged, and 20.5% worsened. No participant with severe disability (n=40) improved to mild. Female sex, older age, higher body mass index, and vertebral fractures (semiquantitative grade ≥2) were significant predictors of worsening disability (p<0.05). Higher baseline ODI was inversely associated with deterioration.

Conclusions: In this population-based cohort, LBP-related disability modestly worsened over 7 years. Older adults, women, individuals with obesity, and those with vertebral fractures were at greatest risk. These findings support early intervention and screening strategies to prevent disability progression in at-risk populations.

Introduction: To evaluate the differences in anterior spinal bridging and sagittal spinal parameters between patients with diffuse idiopathic skeletal hyperostosis (DISH) and ankylosing spondylitis (AS) using whole-spine computed tomography (CT).

Methods: This retrospective study included patients with DISH (n=111) and AS (n=27). The number of anterior spinal bridges and sagittal spinal parameters was evaluated. The sagittal vertical axis (SVA) evaluated by whole-spine CT was defined as sup-SVA. Patients were further evaluated by matching their age and sex.

Results: Anterior spinal bridging frequently occurred in the thoracic spine in DISH and AS. In AS, bridging occurred in the lumbar spine according to the number of anterior spinal bridges. Sup-SVA and T5-T12 thoracic kyphosis (TK) were significantly greater in AS, and lumbar lordosis (LL) was significantly smaller in AS. TK was greater according to the number of anterior spinal bridges in both DISH and AS. Sup-SVA in DISH was greater according to the number of anterior spinal bridges, especially in the thoracic spine, whereas it was greater according to the lumbar in AS. LL in AS was smaller according to the number of lumbar bridges. Sup-SVA in DISH correlated with TK, whereas it correlated with both TK and LL in AS.

Conclusions: In patients with AS, the spine tends to bridge from the lumbar to the thoracic spine, causing kyphosis in the thoracolumbar spine. In patients with DISH, the spine tends to bridge from the thoracic spine, causing kyphosis in the thoracic spine. Thus, sup-SVA is greater in AS than in DISH.

Introduction: This study aimed to identify the factors associated with the postoperative deterioration of sagittal balance after surgery for adult spinal deformity (ASD), focusing on preoperative alignment and pelvic incidence (PI).

Methods: We retrospectively reviewed the medical records of 87 patients who underwent corrective surgery for ASD (2017-2020). Sagittal balance was assessed using the sagittal balance classification (SBC). The patients were classified as balanced (maintained SBC grade 1 or 2) or imbalanced (deteriorated to grade 3). Radiographic parameters, clinical outcomes (Japanese Orthopedics Association scores and mechanical complications), and bone mineral density were analyzed.

Results: In 15 patients (17.2%), the sagittal balance deteriorated to grade 3 (imbalanced group). Factors significantly associated with postoperative deterioration of sagittal balance included preoperative grade 3 SBC (73.3% vs. 23.6%, p<0.001), steroid use (26.7% vs. 2.8%, p<0.01), pelvic fusion (80% vs. 51.4%, p=0.049), higher preoperative PI, sacral slope, and sagittal vertical axis. At 2 years, the imbalanced group showed a significantly greater corrective loss of the lumbar spine. Receiver operating curve analysis identified preoperative PI ≥52.1° as predictive of postoperative imbalance (sensitivity 86.7%, specificity 66.7%). The clinical outcomes were similar, but the reoperation rates were higher in the imbalanced group (20.0% vs. 2.8%, p=0.03).

Conclusions: High preoperative PI, severe sagittal imbalance, steroid use, and pelvic fusion were predictive of postoperative sagittal balance deterioration, underscoring the need for personalized preoperative planning.

Introduction: Endoscopic spine surgery (ESS) presents advantages over traditional microscopic techniques but faces limitations in terms of field of view and depth perception. Virtual reality (VR) devices offer solutions by integrating real-time digital images into the surgical field, enabling magnification and teleproctoring.

Methods: The study was conducted in two phases. In the first phase, 55 surgeons completed a pre-use questionnaire. In the second phase, 19 surgeons participated in cadaveric practical training using the device and completed a post-use survey. Data were analyzed using R software.

Results: Following device use, surgeon confidence in magnification increased significantly (from 21% to 57%), with improved perception of image quality. Acceptance of teleproctoring rose from 33% to 94.7%. The device was considered superior to the operating microscope in both image quality and ergonomics.

Conclusions: VR head-mounted devices enhance visualization in ESS, allow intraoperative access to imaging, and support remote guidance via teleproctoring. Their adoption may contribute to improved training, planning, and surgeon ergonomics. However, additional controlled studies are required to determine their effects on clinical outcomes and operative performance.

Introduction: Surgical decompression is necessary for anterior paradiscal-type thoracic spine tuberculosis with a neurological deficit; nevertheless, if pedicle screw fixation is unsuccessful, laminectomy may result in pan-vertebral instability. No available studies compare traditional anterolateral decompression (ALD) with the convenient, less extensive technique of transpedicular decompression (TPD).

Methods: This randomized comparative study of 20 cases of thoracic spine tuberculosis (T2-T12) used a posterior midline surgical approach with pedicle screw instrumentation. Diseased pedicle removal by eggshell technique (TPD) was compared with decompression by removal of the posterior part of the rib, transverse process, pedicle, and posterolateral part of the diseased vertebral body (ALD).

Results: Both groups had similar lengths of skin incision, intraoperative blood loss, and blood transfusion, but the duration of surgery was significantly less (p-value 0.019) in the TPD (156.5 minutes) than in the ALD group (184.5 minutes). Additional hemi-laminotomy was needed in two cases of TP, in the absence of liquid pus. Both groups showed similar neurological recovery except for one case of multidrug resistance in the ALD group. Improvements in the modified Japanese Orthopedics Association score (p=0.719); visual analog scale (p=0.259) and Nurick scale (p=0.387) had no statistical difference between the two groups. Mean kyphosis correction of 6.64⁰ and 6.45⁰ and mean loss of correction at 2-years were 4.74⁰ and 1.98⁰ in the TPD and ALD groups, respectively. Complications included one case of surgical site infection in each group.

Conclusions: Similar outcomes of both approaches. TPD is quicker but may need hemi-laminotomy in the absence of liquid pus. ALD enables thick organized pus removal without compromising lamina in paradiscal-tuberculosis.

Introduction: Herniated lumbar intervertebral discs migrate into the rostral or caudal anterior epidural space (AES). Previous studies have reported varying frequencies of migration direction, and the factors influencing the migration direction include patient age, affected disc level, and AES structural differences. However, the relationship between AES volume and migration direction remains unclarified. The purpose of this study was to measure the AES volume using computed tomography (CT) imaging and investigate the factors affecting herniated nucleus pulposus (HNP) migration in the sagittal direction.

Methods: We reviewed 42 patients who were surgically treated for migrated lumbar intervertebral disc herniation between 2014 and 2023. The primary endpoint was the ratio of the AES volume between vertebrae adjacent to the herniated disc. The secondary endpoints were patient demographics, disc level, clinical symptoms, disc degeneration, and lumbar instability. AES volume was measured by calculating the area between the posterior vertebral wall concavity and a line connecting the posterior walls on CT images, with the total volume determined as the sum of the slice areas multiplied by the slice width.

Results: A total of 14 patients exhibited rostral HNP migration, while 28 exhibited caudal HNP migration. Rostral HNP migration was associated with a higher prevalence of double-root involvement (p<0.05) and a greater superior/inferior ratio of the AES volume (p<0.01). Multivariate analysis identified the AES volume superior/inferior ratio (odds ratio: 9.551) as a factor significantly associated with the direction of HNP migration.

Conclusions: The HNP tends to migrate toward the direction with a larger AES volume because the herniated material follows the path of least resistance. Clinical presentation of double-root symptoms was strongly indicative of rostral HNP migration.

Introduction: Cervical spinal cord injury (CSCI) without major bone injury is increasing among older adults, particularly in aging societies like Japan. The optimal treatment strategies remain unclear, with conservative therapy often preferred, especially for older patients. However, surgery is frequently necessary due to poor improvement or progression of paralysis during conservative treatment. This study investigated the characteristics and outcomes of older patients with CSCI without major bone injury who transitioned from conservative treatment to surgery.

Methods: This nationwide, retrospective study examined data from patients aged ≥65 years with CSCI without major bone injury. The patients were categorized into 3 groups: conservative treatment, planned surgery, and those who switched from conservative treatment to surgery. The study aimed to identify the risk factors for conservative therapy failure that necessitate surgical intervention and to compare the outcomes between patients who had planned surgery and those who required surgery after conservative management failed.

Results: Among 615 patients, 422 (68.6%) received conservative treatment, 193 (31.4%) had planned surgery, and 116 (18.9%) transitioned from conservative to surgical treatment. Transition to surgery was mainly due to poor improvement or progression of neurological deficits. Significant risk factors for transitioning to surgery included younger age, presence of ossification of the posterior longitudinal ligament, and spinal cord signal changes on magnetic resonance imaging. Comparative analysis showed no significant differences in neurological outcomes between patients who had surgery as planned and those who required surgery after failed conservative treatment.

Conclusions: A significant proportion of older patients with CSCI without major bone injury who were initially managed conservatively eventually required surgery due to insufficient neurological improvement. The outcomes of patients who transitioned to surgery were similar to those who had surgery as initially planned, indicating that careful monitoring of conservative treatment followed by surgery, if necessary, may be an effective approach.