Asian Spine Journal最新文献

Study design: A retrospective cohort study.

Purpose: To investigate the sagittal plane configuration of the entire spine and its association with the risk of adjacent segment degeneration (ASD) after posterior lumbar interbody fusion (PLIF).

Overview of literature: Although PLIF has demonstrated satisfactory clinical outcomes, it is associated with ASD. However, the geometric mechanical changes that contribute to the occurrence of ASD are not well characterized.

Methods: Radiological parameters were extracted from the whole lateral radiographs. Patients were divided into two groups: the ASD group (segmental kyphosis of ≥10º, and/or a ≥50% loss of disc height, and/or ≥3 mm of anteroposterior translation) and the non-ASD group.

Results: All 112 included patients underwent PLIF for lumbar degenerative diseases. The minimum follow-up period was 2 years, with an average follow-up time of 63.6 months. Fifty-two patients (46.4%) were classified into the ASD group and of these, 13 required reoperation due to failure of conservative treatment. Patients with ASD exhibited significantly more caudal and posterior inflection vertebrae (IV), while the lumbar apical vertebra was significantly more caudal immediately after surgery. The IV position was identified as a significant risk factor for ASD, and the ASD incidence was significantly higher in the group where IV ≤5 (L1 vertebral body) than in the group where IV ≥5.5 (T12-L1 disc) (69.0% vs. 38.6%).

Conclusions: The IV position is a significant risk factor for ASD development. Although it is difficult to control intraoperative IV levels, we note a high risk of ASD in patients with IV lower than T12-L1.

Study design: Retrospective observational study.

Purpose: This study aimed to evaluate the utility of cervical dynamic magnetic resonance imaging (dMRI) in the assessment of cervical canal stenosis.

Overview of literature: Cervical spondylotic myelopathy has been intricately linked to both static and dynamic narrowing of the cervical spinal canal. Traditional MRI with the neck in a neutral position fails to identify the dynamic changes and may lead to misdiagnosis. Cervical dMRI is a promising tool for evaluating cervical myelopathy, enabling clinicians to assess spinal cord compression, segmental instability, and alterations in range of motion, often missed on conventional imaging.

Methods: A retrospective analysis was conducted on 369 patients with symptoms of cervical myelopathy assessed using cervical dMRI. After assessing the subaxial cervical spine at each disc level (C3-T1), significant changes in the degree of central canal stenosis were determined. The appearance and extent of hyperintense lesions on T2-weighted sequences were also noted.

Results: Overall, 653/1,845 (35.39%) disc levels showed an increase in stenosis grade on extension MRI, with 168/653 (25.72%) and 180/653 (27.56%) disc levels changing from grades 0/1 to grades 2 and 3, respectively. Moreover, 120/369 (32.52%) patients showed a mean increase of 1.55±0.75 levels of compression on extension MRI when compared to neutral MRI. A fresh-appearing hyperintense lesion was observed in 79 (4.28%) disc levels on flexion MRI, which was not visualized on neutral MRI.

Conclusions: Cervical dMRI may help surgeons plan for surgery, discuss the prognosis with the patient, and safeguard themselves from medico-legal issues arising from improper or missed diagnosis and treatment.

Study design: A fused deposition modeling three-dimensional (3D)-printed model of the L4-5 vertebra for lumbar discectomy was designed. The model included separately printed dura mater, spinal cord, ligamentum flavum, intervertebral disc (from thermoplastic polyurethane), and bony structures (from polylactic acid), and the material cost approximately US$ 1 per model. A simple plumbing endoscope was used for visualization. Dura mater injury was assessed by painting two layers on the dura mater, which peeled off with trauma.

Purpose: Endoscopic spine surgery is a subject of high interest in neurosurgery given its minimally invasive nature; however, it has a steep learning curve. This study evaluated the effectiveness of a cost-efficient 3D-printed model when teaching this technique to neurosurgery residents.

Overview of literature: Only a few studies have investigated the efficacy of such a model.

Methods: Eight residents with >2 years of training participated. Residents performed the procedure bilaterally and twice at 1-week intervals.

Results: From the 32 surgeries, four were excluded because of facet removal (as it widened the surgical corridor), leaving 28 surgeries for analysis. Initial surgeries demonstrated a mean operation time of 21 minutes 18 seconds (standard deviation [SD], 2 minutes 32 seconds), which improved to a mean of 6 minutes 45 seconds (SD, 37 seconds) in the fourth surgery (F(3, 17)=19.18, p <0.0001), demonstrating a significant reduction in surgical time over successive surgeries. The median area with the paint removed decreased, from 161.80 (85.55-217.83) to 95.13 mm2 (12.62-160.54), (F(2.072, Inf)=2.04, p =0.128); however, this was not significant. Resident feedback indicated high satisfaction with the educational value of the model.

Conclusions: The developed fully 3D-printed model provides a viable and scalable option for neurosurgical training programs, enhancing the learning experience while maintaining low costs. This model may be an excellent stepping stone for learning lumbar spine endoscopy, acclimating to the two-dimensional view, progressing to cadaver models, and, eventually, independent surgery.

Herein, we describe a novel posterior lumbar interbody fusion (PLIF) technique with annulus fibrosus (AF) release and the use of expandable cages (called "anterior-release PLIF" [ARPLIF]). In this technique, posterior column osteotomy (PCO) and AF release provide excellent intervertebral mobility. AF release involves circumferentially peeling off the AF above or below the endplate between the fixed vertebrae under radiographic guidance without cutting the AF and anterior longitudinal ligament. Subsequently, high-angle variable-angle expandable cages are used to simultaneously expand both sides before inserting the percutaneous pedicle screws and correcting to achieve good local lumbar lordosis. PCO and AF release achieve excellent intervertebral mobility. Intervertebral mobility and simultaneous expansion of both cages disperse the force on the endplates, reducing cage subsidence, and the high-angle cages facilitate high intervertebral angle creation. The novel ARPLIF intervertebral manipulation technique can promote good local lumbar lordosis formation.

Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of unknown etiology that commonly affects adolescents, imposing significant socioeconomic burdens. Effective management necessitates a comprehensive approach that takes into account multiple factors, including growth potential and psychological issues. Despite significant advancements in AIS management, several questions regarding optimal treatment strategies persist. Recent technological advancements are transforming the treatment landscape, encompassing advancements in bracing, robotic-assisted deformity corrections, and other interventions. This review explores current issues debated in the literature concerning the treatment of AIS, focusing on contemporary high-level evidence (e.g., meta-analyses and randomized controlled trials). Furthermore, this review explores cutting-edge developments and future directions in AIS management, including the integration of artificial intelligence and augmented reality.

Study design: A retrospective cohort study.

Purpose: To examine the effect of cannabis use history on postoperative opioid utilization in patients undergoing one- to three-level lumbar fusion for degenerative spine disease.

Overview of literature: Strategies to minimize dosing and chronic opioid use are needed for spine surgery given their widespread prescription for postsurgical pain management.

Methods: In this database study, medical coding was used to identify patients who had undergone one- to three-level lumbar fusions between 2012 and 2021. Propensity score matching was used to create two equal cohorts with respect to cannabis use history. Opioid utilization rates (morphine milligram equivalents [MME]/day) and overuse rates at 6 months post-index procedure were assessed. All pvalues <0.05 were considered statistically significant.

Results: Following examination of 153,500 patient records, 1,216 patients were matched into cannabis user and non-cannabis user cohorts. Cannabis users had lower rates of opioid utilization compared to non-cannabis users as early as 2 months after fusion (47.7% vs. 41.1%, p <0.05), a relationship which persisted at 6 months (46.2% vs. 37.7%, p <0.01). Additionally, cannabis users had lower rates of high-dose opioid utilization (≥100 MME per day) during the initial 14-30 days following surgery (6.91% vs. 3.79%, p <0.05).

Conclusions: Patients with a history of cannabis use were less likely to be using opioids as early as 2 months postoperatively and had lower rates of high-dose opioid utilization in the immediate postoperative period. Physicians operating on these patients should consider their cannabis use patterns to provide appropriate titration of pain medication over time.

The purpose of this systematic review and meta-analysis is to assess existing literature and determine the association between the Hounsfield unit (HU) value and the vertebral body quality (VBQ) score with mechanical complications (MCs) after adult spinal deformity (ASD) surgery. Although bone quality is considered an increasingly important factor for MCs after ASD surgery, the utility of the HU value assessed by computed tomography and the VBQ score assessed by magnetic resonance imaging remains unknown. A systematic review of PubMed, Embase, and Cochrane Library databases was performed to find studies evaluating the association between the HU value and the VBQ score with MCs after ASD surgery. In the subsequent meta-analysis, MC outcomes were combined using a random-effects model, and the standardized mean difference and 95% confidence interval were calculated. The final analysis included a total of 20 studies. Nineteen studies reported HU values, and two studies reported VBQ scores. Proximal junctional kyphosis/failure (PJK/PJF) was reported as the MC in 16 studies, whereas other MCs were included in 6 studies. Six studies with a pool of 506 patients with ASD revealed that preoperative HU values at the upper instrumented vertebra (UIV) and UIV+1 were significantly lower in patients with PJK/PJF (standardized mean difference, -0.74; 95% confidence interval, -1.09 to -0.40). Three studies suggested an cutoff HU value of approximately ≤120, yielding a pooled sensitivity of 0.77, specificity of 0.67, and diagnostic odds ratio of 7.01. However, two studies reported conflicting results on the relationship between the VBQ score and PJK/PJF. Low HU values predicted the risk of certain MCs, particularly PJK/PJF, after ASD surgery. An HU value of <120 should alert surgeons to be cautious about the postoperative occurrence of PJK/PJF. Future studies are needed to validate the cutoff HU value and evaluate the utility of the VBQ score.

Study design: Prospective single-center study.

Purpose: To compare the accuracy of pedicle screws placed by freehand and under fluoroscopy and robotic assistance with intraoperative image acquisition.

Overview of literature: Pedicle screws are the most commonly used spinal anchors owing to their ability to stabilize all three spinal columns. Various techniques such as freehand, fluoroscopy-assisted, and navigation-assisted pedicle screw placements have been used with varying degrees of accuracy. Most studies on robotic-assisted pedicle screw placement have utilized preoperatively acquired computed tomography scans. To our knowledge, this is the only study in the literature that compared freehand with fluoroscopy-guided and robotic-assisted pedicle screw insertion with freehand and fluoroscopy.

Methods: In this prospective study, a total of 1,120 pedicle screws were placed in the freehand group (n=175), 1,250 in the fluoroscopyassisted group (n=172), and 1,225 in the robotic-assisted group (n=180). Surgical parameters and screw accuracy were analyzed between the three groups. The preoperative plan overlapped with the postoperative O-arm scan to determine if the screws were executed as planned.

Results: The frequency of clinically acceptable screw placement (Gertzbein-Robbins grades A and B) in the freehand, fluoroscopy-assisted, and robotic-assisted groups were 97.7%, 98.6%, and 99.34%, respectively. With robotic assistance, an experience-neutralizing effect implied that surgeons with varying levels of experience achieved comparable pedicle screw accuracy, blood loss, O-arm time, robot time, and time per screw. No significant difference in these parameters was found between surgeries commencing before and after 2 PM. No significant differences were noted between the planned and executed screw trajectories in the robotic-assisted group irrespective of surgical experience.

Conclusions: The third-generation robotic-assisted pedicle screw placement system used in conjunction with intraoperative threedimensional O-arm imaging consistently demonstrates safe and accurate screw placement with an experience-neutralizing effect.

Study design: A modified Delphi study.

Purpose: This study sought to establish expert consensus on the use of cortical bone trajectory (CBT) for lumbar pedicle screws.

Overview of literature: The CBT technique is widely used in the treatment of various degenerative lumbar diseases because it reduces surgical time, soft tissue exposure, and blood loss; improves biomechanical stability; and allows for faster patient recovery. However, as an emerging surgical technique, CBT remains controversial in terms of preoperative evaluation methods, key surgical techniques, complication prevention and treatment, postoperative follow-up, and other aspects, resulting in unclear indications and contraindications for some doctors and posing great challenges to the steady promotion of this technique.

Methods: From May 2021 to August 2021, panelists were chosen to collect expert feedback using the modified Delphi method, and 74 spine surgeons from across China agreed to participate. Four rounds were conducted: one in-person meeting and three subsequent survey rounds. Each question received at least 70.0% agreement, indicating a consensus. The grade A, B, and C recommendation were defined as having ≥90.0%, 80.0%-89.9%, and 70.0%-79.9% agreement on each question, respectively.

Results: The panelist group consisted of 74 experts, and 72, 70, and 69 questionnaires were collected in three rounds, respectively. In total, 24 questions with 59 options reached consensus after the Delphi rounds, including indications (adjacent vertebral diseases after lumbar internal fixation) and contraindications (previous surgery or bone destructive diseases lead to the destruction or absence of bone in the lamina or isthmus); advantages (intraoperative traction of paravertebral soft tissue is small) and disadvantages (not three-column fixation.); preoperative evaluation; complications; and postoperative follow-up evaluation, of CBT.

Conclusions: The modified Delphi method achieved expert consensus on the clinical use of CBT for lumbar pedicle screws. This consensus document establishes clear guidelines for indications, contraindications, surgical techniques, and postoperative management, thereby enhancing clinical decision-making and promoting the safe and effective use of CBT. While the initial study focused on Chinese surgeons, future research will seek to validate and expand these findings from a broader international perspective.