Asian Spine Journal最新文献

Study design: Retrospective cross-sectional study.

Purpose: To investigate the size and local anatomy of the right and the left-sided oblique corridors between L1-L5 levels and identify the potential impact of increasing age and sex on corridor size.

Overview of literature: The oblique lumbar interbody fusion (OLIF) was introduced by Silvestre and his colleagues as a solution to the approach-related complications associated with anterior lumbar interbody fusion and lateral lumbar interbody fusion. Limited data were available describing the local anatomy and morphology of this approach.

Methods: Imaging data of 300 patients (150 males and 150 females) who underwent 1.5T magnetic resonance imaging (MRI) scans of the lumbar spine at Indian Spinal Injuries Centre, New Delhi, India between January 2023 and January 2024 were retrospectively reviewed. The cohort was stratified into six age groups (21-30, 31-40, 41-50, 51-60, 61-70, and >70 years) with 25 patients in each age group for both sexes. T2 weighted axial MRI images were analyzed from the L1-L5 level at the mid-disc level to calculate the corridor size. The local anatomical differences were recorded.

Results: At L1-L2, L2-L3, L3-L4, and L4-L5 levels, the mean corridor sizes in males were 17.48, 15.50, 13.41, and 9.32 mm on the left side, and 11.48, 7.12, 4.34, and 1.64 mm on the right side, respectively. The corresponding mean corridor sizes in females were 10.34, 12.94, 12.64, and 7.22 mm on the left side and 2.66, 3.52, 3.69, and 1.64 mm on the right side, respectively. For both sides, the corridor size was significantly affected by sex, increased with age, and decreased at the lower lumbar disc levels.

Conclusions: A left-sided OLIF approach is more feasible for both sexes. The right-sided approach is less likely to be performed effectively.

Study design: Matched case-control study.

Purpose: To evaluate the midterm outcomes of unilateral pedicle screw fixation (UPSF) versus bilateral pedicle screw fixation (BPSF) in transforaminal lumbar interbody fusion (TLIF) procedure, ascertain efficacy of UPSF in adequately decompressing contralateral foramen+spinal canal and reducing rate of adjacent segment degeneration (ASD) at 4-8-year follow-up (FU).

Overview of literature: Previous meta-analyses found no significant differences between UPSF and BPSF regarding fusion rates, clinical and radiological outcomes; however, few studies have reported higher rates of cage migration/subsidence and pseudoarthrosis in the UPSF. No study has evaluated the impact of UPSF on indirect decompression and ASD.

Methods: Retrospective analysis of 319 patients treated with UPSF vs. 331 patients treated with BPSF between 2012 to 2020. Clinical and radiological outcomes were evaluated at 6 months, 1 year, 2 years, and 4 years postoperatively. X-rays were used to assess fusion+ASD and computed tomography scans in doubtful cases. Magnetic resonance imaging was used at last FU to determine cross-sectional area of cord (CSA), foraminal height (FH), and width (FW) restoration.

Results: The mean FU duration was 50 months (range, 44-140 months). In UPSF, CSA increased by 2.3 times from preoperative values; FH and FW increased by 25% and 17.5%, respectively, at last FU (p<0.001); fusion rate was 94.3%, comparable to BPSF (similar CSA, FW, FH, 96.4% fusion rate). In UPSF, adjacent disc height remained stable, from preoperative 11.39±2.03 to 10.97±1.93 postoperatively at 4 years and 10.03±1.88 at 8 years. BPSF showed ASD in 14 (4.47%) vs. three patients (1.06%) in UPSF (p<0.04). Complication rates were similar (6.58% UPSF vs. 6.04% BPSF, p>0.05).

Conclusions: UPSF-TLIF is comparable to BPSF in terms of patient-reported clinical outcomes, fusion rates, and complication rates while being superior in terms of lesser ASD. UPSF enables radiologically and clinically significant contralateral indirect neural foraminal decompression and canal decompression without disturbing the contralateral side anatomy, unlike BPSF.

Study design: A prospective study.

Purpose: To diagnose scoliosis, a visit to the hospital for radiography is typically necessary. In such cases, children with scoliosis are exposed to radiation, which may place their health at risk. Therefore, we sought to determine whether a classification method based on visual body images obtained through photography can be used to diagnose scoliosis.

Overview of literature: Scoliosis can be diagnosed and classified into various types using radiographs. However, no studies have attempted to classify scoliosis based on visual body images.

Methods: From January 1, 2019 to December 31, 2022, 136 patients newly diagnosed with Adolescent idiopathic scoliosis and 124 healthy candidates from our institution were enrolled. This study classified body images into five types based on visual confirmation of the positional relationship of the body. The accuracy of this classification method was identified by calculating its sensitivity, specificity, and reproducibility of this classification method within and between observers according to kappa value.

Results: Overall, 136 patients and 124 control subjects who visited the Pusan National University Hospital, Busan, Korea were photographed and compared by obtaining back images and X-ray radiographs. The sensitivity and specificity of the classification method showed a satisfactory-to-good degree of accuracy, although the degree varies depending on the visual body image type. The classification methods exhibited good intraobserver reliability (κ=0.855) and moderate interobserver reliability (κ=0.751).

Conclusions: Our classification method showed a high degree of sensitivity and specificity (98.1% sensitivity, 98.9% specificity, and 98.4% accuracy) while exhibiting high reproducibility and ease of access. Based on our findings, we believe that our classification method can be used for scoliosis screening.

Study design: A prospective web-based survey.

Purpose: Although intraoperative neurophysiological monitoring (IONM) is critical in spine surgery, its usage is largely based on the surgeon's discretion, and studies on its usage trends in Asia-Pacific countries are lacking. This study aimed to examine current trends in IONM usage in Asia-Pacific countries.

Overview of literature: IONM is an important tool for minimizing neurological complications and detecting spinal cord injuries after spine surgery. IONM can be performed using several modalities, such as transcranial electrical stimulation-muscle evoked potentials (Tc-MEP) and somatosensory evoked potentials (SEP).

Methods: Spine surgeons of the Asia-Pacific Spine Society were asked to respond to a web-based survey on IONM. The questionnaire covered various aspects of IONM, including its common modality, Tc-MEP details, necessities for consistent use, and recommended modalities in major spine surgeries and representative surgical procedures.

Results: Responses were received from 193 of 626 spine surgeons. Among these respondents, 177 used IONM routinely. Among these 177 respondents, 17 mainly used SEP, whereas the majority favored Tc-MEPs. Although a >50% decrease is the commonly used alarm point in Tc-MEP, half of the Tc-MEP users had no protocols planned for such scenarios. Moreover, half of the Tc-MEP users experienced complications, with bite injuries being the most common. Most respondents strongly recommended IONM in deformity surgery for pediatric and adult populations and tumor resection surgery for intramedullary spinal cord tumors. Conversely, IONM was the least recommended in lumbar spinal canal stenosis surgery.

Conclusions: Spine surgeons in Asia-Pacific countries favored IONM use, indicating widespread routine utilization. Tc-MEP was the predominant modality for IONM, followed by SEPs.

The purpose of this systematic review and meta-analysis is to evaluate the safety and efficacy of anti-inflammatory-impregnated gelatin sponges in spine surgeries. Gelatin sponges are increasingly used as delivery vehicles for anti-inflammatory and analgesic drugs during spine surgeries. However, concerns about their safety and efficacy persist. A comprehensive literature search was conducted to identify original research articles investigating the use of anti-inflammatory-impregnated gelatin sponges in spine surgeries from 2006 to 2024. Case reports, case series, animal studies, cadaveric studies, and abstract-only articles were excluded. The risk of bias was assessed using Cochrane Risk of Bias 2.0 (Cochrane, UK) for randomized controlled trials (RCTs) and the Newcastle Ottawa Scale (NOS) for observational studies. Meta-analysis was performed using Cochrane Review Manager Web. Thirteen studies (six RCTs, six cohort studies, and one case-control study) were included. Pooled analysis revealed a significant decrease in Visual Analog Scale (VAS) score for back pain (mean difference [MD], -0.62; 95% confidence intervals [CI], -0.78 to -0.46; p<0.00001), VAS score for leg pain (MD, -0.60; 95% CI, -0.87 to -0.34; p<0.00001), and length of hospital stay (MD, -0.99; 95% CI, -1.68 to -0.31; p=0.0004). Additionally, there was a significant increase in the Japanese Orthopedic Association score (MD, 0.98; 95% CI, 0.00 to 1.96; p=0.05). However, no significant difference was observed in the disability index (MD, -0.59; 95% CI, -1.88 to -0.70; p=0.37). The use of anti-inflammatory-impregnated gelatin sponges during spine surgeries decreases postoperative back pain and leg pain, reduces length of stay, and improves neurological function. Larger, prospective, randomized trials are required to obtain more robust evidence.

Study design: This study employed a patient-specific finite element model.

Purpose: To quantify the effect of anterior and posterior surgical approaches on adjacent segment biomechanics of the patient-specific spine and spinal cord.

Overview of literature: Adjacent segment degeneration (ASD) is a well-documented complication following cervical fusion, typically resulting from accelerated osteoligamentous deterioration and subsequent symptomatic neural compression. Despite the known impact of spinal fusion on adjacent segment biomechanics, comprehensive comparison between anterior and posterior surgical approaches remains elusive. Understanding these biomechanical changes is crucial for predicting and managing ASD, thereby aiding preoperative surgical planning.

Methods: Patient-specific finite element modeling (FEM) of the cervical spine and spinal cord were created. Surgical simulation was performed for multi-segment anterior cervical discectomy fusion (ACDF) (C4-C7) and posterior cervical laminectomy with fusion (PCLF) (C5-6 laminectomy and C4-C7 fusion). Physiological motions were simulated by applying a 2 Nm moment and 75 N force.

Results: At the superior adjacent segment, the ACDF model exhibited a higher range of motion (ROM) during neck flexion compared to PCLF. Conversely, in neck extension, PCLF showed a higher ROM than ACDF. At the superior adjacent segment, the ACDF model showed greater spinal cord stress during flexion. During extension, PCLF was associated with greater spinal cord stress. At the inferior adjacent segment, ACDF was associated with greater spinal cord stress than PCLF during flexion. At the superior adjacent segment, ACDF also led to increased intradiskal pressure and capsular ligament strain during flexion, whereas PCLF showed these increases during extension.

Conclusions: Our findings indicate the differential effect of ACDF and PCLF on biomechanics at the cervical spine's adjacent segments, with the patient-specific model with ACDF showing greater changes and potential for degeneration. This study highlights the utility of patient-specific FEMs in enhancing surgical decision-making through personalized medicine.

Study design: A retrospective comparative study.

Purpose: To validate the hypothesis that a combination of multilevel Ponte osteotomy (PO) with intraoperative traction (IOT) results in a better correction than IOT alone in high-magnitude curves in adolescent idiopathic scoliosis (AIS) and does not possess an attributable risk of neurological injury.

Overview of literature: On a comprehensive review of the literature, the choice of technique adopted for curves between 65° and 100° remains controversial with no major consensus favoring one technique over the other.

Methods: Twenty-four patients with AIS (Cobb >65°) underwent surgery at a single center between January 2014 and December 2021. The first 10 patients underwent surgery using only IOT (T group), whereas the subsequent 14 patients underwent surgery with a combination of IOT and PO (TP group).

Results: The mean preoperative Cobb angles in the T and TP groups were 89.35°±6.05° and 92.32°±9.28°, respectively (p=0.59). The mean flexibility index (FI) of the T and TP groups were 0.31±0.016 and 0.36±0.03, respectively (p=0.41). The mean postoperative Cobb angle in the T and TP groups were 40.25°±5.95° and 19.1°±3.20°, respectively (p=0.041). Apical vertebral rotation improved from mean grade 3.2 (2-4) to grade 2.6 (1-3) in the T group and from mean grade 3.6 (2-4) to mean grade 1.8 (1-3) in the TP group. Postoperatively, the mean thoracic kyphosis was 13.84°±2.10° and 21.02°±1.68° in T and TP groups (p=0.044). Transient signal-loss intraoperatively was noted in two patients, one in each group. No episodes of postoperative neurological deficits were reported. No incidences of pseudarthrosis/implant-related complications were reported at the end of 2 years in either group.

Conclusions: IOT and PO complement one another and can be safely combined without an attributable risk of neurological injury.

Study design: A cross-sectional study.

Purpose: This study aimed to define the normal values of the lumbar lordosis curve (LLC) and investigate its association with sex, age, and body mass index (BMI).

Overview of literature: The importance of the human spine's sagittal alignment, particularly in the lumbar region, has been argued from the physiological and pathophysiological points of view. The LLC size is an important predictor of lumbar pathologies. Lumbar curvature misalignment, particularly increased lumbar lordosis or hypolordosis, can, in the long term, lead to spinal instability and development of disorders such as low back pain and spondylolisthesis Therefore, knowledge about the normal LLC value and its association with age, sex, and BMI, appears crucial.

Methods: The study recruited 2,497 asymptomatic volunteers (1,264 women and 1,233 men) aged 5-85 years. Participants were assigned to different groups based on their sex, age, and BMI. The LLC was measured using a Flexicurve.

Results: Normal LLC values were established for different sexes, age, and BMI groups. Overall, normal LLC ranges from 10.2° to 74.9° with a mean of 42.34°±13° (male, 38.57°±11.44°; female, 46°±13.38°). LLC was generally higher by 7.5° in women than in men. A significant three-way interaction of sex, age, and BMI with LLC was found. The association of age and BMI with LLC was also significant.

Conclusions: Our results can be used as a reference by physicians, healthcare, etc., when the LLC values in different ages and sexes are measured noninvasively. In other words, this information can be used as reference when determining whether the obtained LLC is within the normal range.

Computed tomography (CT) is widely used for the diagnosis and surgical treatment of spinal pathologies, particularly for pedicle screw placement. However, CT's limitations, notably radiation exposure, necessitate the development of alternative imaging techniques. Synthetic CT (sCT), which generates CT-like images from existing magnetic resonance imaging (MRI) scans, offers a promising alternative to reduce radiation exposure. This study examines the emerging role of sCT in spinal surgery, focusing on usability, efficiency, and potential impact on surgical outcomes. This qualitative literature review evaluated various sCT generation methods, encompassing traditional atlas-based and bulk-density models, as well as advanced convolutional neural network (CNN) architectures, including U-net, V-net, and generative adversarial network models. The review assessed sCT accuracy and clinical feasibility across different medical disciplines, particularly oncology and surgery, with potential applications in orthopedic, neurosurgical, and spinal surgery. sCT has shown significant promise across various medical disciplines. CNN-based techniques enable rapid and accurate generation of sCT from MRI scans, rendering clinical use feasible. sCT has been used to identify pathologies and monitor disease progression, suggesting that MRI alone may suffice for diagnosis and planning in the future. In spinal surgery, sCTs are particularly useful in visualizing key anatomical features like vertebral dimensions and spinal canal diameter. However, challenges persist, especially in visualizing complex structures and larger spinal regions, like the lumbar spine. Additional limitations include inaccuracies stemming from surgical implants and image variability. The application of sCT technology in spinal surgery holds great promise, improving diagnostics, planning, and treatment outcomes. Although further research is required to improve its precision, it offers a viable alternative to traditional CT in many clinical contexts, with the potential for broader application as the technology matures.