Exploring the impact of mild-to-moderate foraminal stenosis at L5-S1 on clinical outcomes following L4-5 posterior lumbar interbody fusion

BACKGROUND CONTEXT

Patients scheduled for L4-5 PLIF often have FS at L5-S1. However, data on the clinical and radiographic outcomes of cases with mild-to-moderate L5-S1 FS are lacking, which may affect clinical outcomes or require additional surgery after L4-5 fusion.

PURPOSE

To evaluate the clinical and radiographic outcomes of L4-5 PLIF in patients with and without mild-to-moderate L5-S1 FS, with a primary focus on the association between L5-S1 FS and postoperative clinical outcomes including back pain, leg pain, and scores on the oswestry disability index (ODI) and EuroQol 5-dimension (EQ-5D).

STUDY DESIGN

Retrospective comparative study.

PATIENT SAMPLE

A retrospective review of patients who underwent L4-5 PLIF from 2014 to 2018. The patients were divided according to the presence of mild-to-moderate FS at L5-S1.

OUTCOME MEASURES

Clinical assessment included the pain visual analog scale (VAS), ODI, and EQ-5D score. Radiographic assessments included spinopelvic parameters and grades for central and foraminal stenosis.

METHODS

Clinical outcomes were assessed using validated outcome measures at preoperative, 6-month, 12-month, and 36-month follow-up visits. Radiographic evaluations were performed using preoperative and postoperative radiographs. Foraminal stenosis was assessed qualitatively using MRI with a grading system from none to severe and quantitatively by measuring changes in the foraminal area on CT.

RESULTS

Among 186 patients, 55 were categorized as the FS group and 131 as the non-FS group. The FS group was older (p=0.039) and had more severe central stenosis at L5-S1 (p=0.007) as well as more severe FS at both L4-5 and L5-S1 (both p<0.001). Preoperative disc height (p<0.001), C7-S1 sagittal vertical axis (p=0.003), lumbar lordosis (p=0.005), and pelvic incidence-lumbar lordosis mismatch (p=0.026) were more aggravated in the FS group. The FS group showed inferior clinical outcomes at the final follow-up in terms of back pain (p=.010) and ODI score (p=.003).

CONCLUSION

The presence of mild-to-moderate FS at L5-S1 was associated with more aggravated sagittal balance in terms of smaller preoperative disc height, larger sagittal vertical axis, smaller lumbar lordosis, and larger pelvic incidence-lumbar lordosis mismatch. Patients with L5-S1 FS also had poorer clinical outcomes including back pain and ODI score after L4-5 PLIF. Patients with L5-S1 FS need to be carefully examined before L4-5 fusion considering their adverse outcomes due to underlying degenerative changes.

Characterization of the intestinal transport mechanism of polystyrene microplastics (MPs) and the potential inhibitory effect of green tea extracts on MPs intestinal absorption

The aims of the current study included characterizing the intestinal transport mechanism of polystyrene microplastics (MPs) with different charges and sizes in the intestinal epithelial cell model and determining the inhibitory effect of green tea extracts (GTEs) on the intestinal absorption of MPs in Caco-2 cells. The smaller sizes, which included diameters of 0.2 μm, of amine-modified MPs compared to either larger size (1 μm diameter, or carboxylate-MPs (0.2 and 1 μm diameter) significantly lowered the cell viability of caco-2 cells that were measured by MTT assay (p < 0.05). The transported amount (particles/mL of the cell media) of amine-modified MPs by the Caco-2 cell, was not dependent according to the concentrations, energy, or temperature, but it was higher than the carboxylate-modified MPs. The co-treatment of GTEs with the amine-modified MPs inhibited Caco-2 cell cytotoxicity as well as reduced the production of intracellular reactive oxygen species (ROS) in HepG2 generated by the exposure of amine-modified MPs. The GTEs co-treatment also increased trans-epithelial electrical resistances (TEER) and reduced the transportation of Lucifer Yellow via the Caco-2 monolayer compared to only the amine-modified MPs exposure. The GTEs treatment led to a decrease in the number of amine-modified MPs transported to the basal side of the Caco-2 monolayer. The results from our study suggest that the consumption of GTEs could enhance the intestinal barrier function by recovering intestinal epithelial cell damage induced by MPs, which resulted in a decrease of the intestinal absorption of MPs.

Reoperation Rates According to Surgical Approach After Operation for Degenerative Cervical Pathology in Patients With Athetoid Cerebral Palsy: A Nationwide Cohort Study

STUDY DESIGN

National population-based cohort study.

OBJECTIVE

The overall complication rate for patients with athetoid cerebral palsy (CP) undergoing cervical surgery is significantly higher than that of patients without CP. The study was conducted to compare the reoperation and complication rates of anterior fusion, posterior fusion, combined fusion, and laminoplasty for degenerative cervical myelopathy/radiculopathy in patients with athetoid cerebral palsy.

METHODS

The Korean Health Insurance Review and Assessment Service national database was used for analysis. Data from patients diagnosed with athetoid CP who underwent cervical spine operations for degenerative causes between 2002 and 2020 were reviewed. Patients were categorized into four groups for comparison: anterior fusion, posterior fusion, combined fusion, and laminoplasty.

RESULTS

A total of 672 patients were included in the study. The overall revision rate was 21.0% (141/672). The revision rate was highest in the anterior fusion group (42.7%). The revision rates of combined fusion (11.1%; hazard ratio [HR], .335; P = .002), posterior fusion (13.8%; HR, .533; P = .030) were significantly lower than that of anterior fusion. Revision rate of laminoplasty (13.1%; HR, .541; P = .240) was also lower than anterior fusion although the result did not demonstrate statistical significance.

CONCLUSION

Anterior fusion presented the highest reoperation risk after cervical spine surgery reaching 42.7% in patients with athetoid CP. Therefore, anterior-only fusion in patients with athetoid CP should be avoided or reserved for strictly selected patients. Combined fusion, with the lowest revision risk at 11.1%, could be safely applied to patients with athetoid CP.

Does Preoperative Radiation Therapy Performed for Metastatic Spine Cancer at the Cervical Spine Increase Perioperative Complications of Anterior Cervical Surgery?

Background

Radiation therapy (RT) performed before anterior cervical spine surgery (ACSS) may cause fascial plane fibrosis, decreased soft-tissue vascularity, and vertebral body weakness, which could increase the risk of esophageal and major vessel injuries, wound complications, and construct subsidence. Therefore, this study aimed to evaluate whether preoperative RT performed for metastatic spine cancer (MSC) at the cervical spine increases perioperative morbidity for ACSS.

Methods

Forty-nine patients who underwent ACSS for treatment of MSC at the cervical spine were retrospectively reviewed. All the patients underwent anterior cervical corpectomy via the anterior approach. Patient demographics, surgical factors, operative factors, and complications were recorded. Results of patients who were initially treated with RT before ACSS (RT group) were compared with those who did not receive RT before ACSS (non-RT group).

Results

Eighteen patients (36.7%) were included in the RT group, while the remaining 31 (63.3%) were included in the non-RT group. Surgery-related factors, including operation time (p = 0.109), estimated blood loss (p = 0.246), amount of postoperative drainage (p = 0.604), number of levels operated (p = 0.207), and number of patients who underwent combined posterior fusion (p = 0.768), did not significantly differ between the 2 groups. Complication rates, including esophageal injury, dural tear, infection, wound dehiscence, and mechanical failure, did not significantly differ between the RT and non-RT groups. Early subsidence was significantly greater in the non-RT group compared to that in the RT group (p = 0.012).

Conclusions

RT performed before surgery for MSC does not increase the risk of wound complication, mechanical failure, or vital structure injury during ACSS. The surgical procedural approach was not complicated by previous RT history. Therefore, surgeons can safely choose the anterior approach when the number of levels or location of MSC favors anterior surgery, and performing a posterior surgery is unnecessary due to a concern that previous RT may increase complication rates of ACSS.

Shoulder balance in Lenke type 2 adolescent idiopathic scoliosis: correlations among radiological indices, cosmetic indices, and patient-reported outcomes

OBJECTIVE

The aim of this study was to investigate the correlation between radiological indices of shoulder balance (SB) and cosmetic indices of shoulder deformity in patients with Lenke type 2 adolescent idiopathic scoliosis (AIS) and to determine the extent to which patient-reported outcomes (PROs) correlate with these measurements. Current management decisions and outcomes for SB in AIS are primarily based on radiological measurements. It is crucial to understand how these radiological parameters and cosmetic indices relate to patient satisfaction.

METHODS

The authors analyzed the preoperative radiological and photographic indices of SB, along with PROs, in patients with Lenke type 2 AIS. Lateral SB parameters included the radiological shoulder height (RSH) and clavicle angle, while medial SB parameters included the first rib angle and T1 tilt angle. Photographic indices included the shoulder height angle (SHA), axilla height angle (AHA), and the left/right trapezius angle (LRTA) ratio. The authors assessed the self-image, mental health, and total score domains of the Korean version of the 22-item Scoliosis Research Society questionnaire.

RESULTS

In their analysis of Lenke type 2 patients, the authors found that correlation coefficients between radiological measurements and photographic indices ranged from -0.25 to 0.47, among which only lateral SB including clavicle angle and RSH showed a significant correlation with anterior and posterior photographic indices. No statistically significant correlations were found between radiological measurements and PROs. Anterior photographic indices including SHA and AHA significantly correlated with all three PROs (p < 0.05).

CONCLUSIONS

Radiological shoulder parameters did not accurately reflect the perceived SB. Anterior photographic indices were reliable for evaluating clinical SB in patients with Lenke type 2 AIS and correlated with PROs. Spine surgeons may benefit from paying more attention to anterior photographic indices when making surgical decisions regarding clinical SB.

Effect of Osteoporosis on Clinical and Radiological Outcomes Following One-Level Anterior Cervical Discectomy and Fusion

Study Design

Retrospective study.

Purpose

This study aimed to evaluate how osteoporosis affected the clinical and radiological outcomes of patients who underwent anterior cervical discectomy and fusion (ACDF) with plating.

Overview of Literature

The incidence of complications associated with implants is high when ACDF is performed in patients with poor bone quality.

Methods

In total, 101 patients without (T-score ≥1.0, group A) and 25 with (T-score ≤-2.5, group B) osteoporosis who underwent single-level ACDF with plating were followed up for >2 years. The clinical and radiological outcomes were compared between the two groups. The fusion rate and implant-related complications were evaluated.

Results

Although clinical outcomes such as visual analog scale scores for the arm (2.0±2.3 vs. 2.4±2.9, p=0.490) and neck pain (1.4±1.9 vs. 1.8±2.2, p=0.343) and neck disability index (7.7±7.1 vs. 9.9±7.5, p=0.225) were slightly higher in group B, no statistically significant difference was noted. Cage subsidence (13.9% vs. 16.0%, p=0.755) and plate migration (7.9% vs. 8.0%, p=1.000) rates did not differ between the two groups. The fusion rate at 1 year postoperatively was higher in group A than in group B (80.3% vs. 68.2%, p=0.139) and slightly increased in both groups (94.6% vs. 86.4%, p=0.178) at the final follow-up.

Conclusions

Osteoporosis did not significantly affect the rate of cage subsidence or plate migration after cervical fusion. After ACDF, increased cage subsidence and implant migration rates had no significant effect on clinical outcomes.

Meta-Analysis on Efficacy and Complications of Bone Morphogenetic Protein-2 for Posterior Fusion of Cervical Spine

OBJECTIVE

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is effective for promoting robust fusion for long-level cervical deformity and revision surgeries. However, only a few studies have reported its efficacy and complications in posterior cervical fusion (PCF).

METHODS

Therefore we evaluated the efficacy and complications of rhBMP-2 application in PCF surgery by searching 3 electronic databases (PubMed, Cochrane Database, and EMBASE) for studies that evaluated the use of rhBMP-2 in PCF. Five studies (1 prospective and 4 retrospective) were included in the meta-analysis.

RESULTS

The quality of each study was assessed, and data on pseudarthrosis, wound infection, neurologic, and immediate medical complications were extracted and analyzed. We found that the use of rhBMP-2 in PCF showed significant benefits in terms of pseudarthrosis and no significant increases in the risk for neurologic and immediate medical complications regardless of the dose. However, high-dose (>2.1 mg/level) rhBMP-2 was a risk factor for wound infection after PCF.

CONCLUSIONS

Our meta-analysis of the currently available literature suggests that patients with PCF may benefit from BMP-2 usage without increasing the risk of complications. However, dose control and containment are important to ensure a low risk of complications.

Does Sacral Slanting Affect Postoperative Shoulder Balance in Patients With Lenke Type 2A Adolescent Idiopathic Scoliosis?

OBJECTIVE

Even minor sacral slanting can influence T1 tilt and shoulder balance. Yet, the relationship between sacral slanting and postoperative shoulder imbalance (PSI) has not been previously explored. To determine risk factors for PSI in Lenke 2A adolescent idiopathic scoliosis (AIS) patients, with an emphasis on sacral slanting.

METHODS

The study encompassed 96 consecutive patients who had undergone posterior correction and fusion surgery for Lenke type 2A AIS. Patients were grouped into PSI(+) and PSI(-) based on postoperative outcomes. Additionally, they were classified into left-sided slanting, no slanting, and right-sided slanting groups according to the degree of sacral slanting. Various radiological measures were compared.

RESULTS

Patients in the PSI(+) group exhibited a smaller preoperative proximal thoracic curve and a higher main thoracic curve correction rate than those in the PSI(-) group. The presence or absence of sacral slanting did not exhibit a significant variation in PSI occurrence. However, the right-sided sacral slanting group showed a larger delta radiologic shoulder height compared to the other 2 groups (7.1 mm vs. 1.5 & 3.3 mm).

CONCLUSION

Sacral slanting was not directly linked to the development of PSI. Despite the common postoperative elevation of the left shoulder, the shoulder height differences decreased over the follow-up period. Especially in cases with a right-sided tilted sacrum, the PSI demonstrated progressive improvement, with an associated increase in the rightward distal wedging angle, leading to distal adding-on.

Novel Screw Placement Method for Extremely Small Lumbar Pedicles in Scoliosis

Study Design: Consecutive case series. Objective: To propose a screw placement method in patients with extremely small lumbar pedicles (ESLPs) (<2 mm) to maintain screw density and correction power, without relying on the O-arm navigation system. Summary of Background Data: In scoliosis surgery, ESLPs can hinder probe passage, resulting in exclusion or substitution of the pedicle screws with a hook. Screw density affects correction power, making it necessary to maximize the number of screw placements, especially in the lumbar curve. Limited studies provide technical guidelines for screw placement in patients with ESLPs, independent of the O-arm navigation system. Methods: We enrolled 19 patients who underwent scoliosis correction surgery using our novel screw placement method for ESLPs. Clinical, radiological, and surgical parameters were assessed. After posterior exposure of the spine, the C-arm fluoroscope was rotated to obtain a true posterior-anterior view and both pedicles were symmetrically visualized. An imaginary pedicle outline was presumed based on the elliptical or linear shadow from the pedicle. The screw entry point was established at a 2 (or 10) o'clock position in the presumed pedicle outline. After adjusting the gear-shift convergence, both cortices of the transverse process were penetrated and the tip was advanced towards the lateral vertebral body wall, where an extrapedicular screw was placed with tricortical fixation. Results: Out of 90 lumbar screws in 19 patients, 33 screws were inserted using our novel method, without correction loss or complications during an average follow-up period of 28.44 months, except radiological loosening of one screw. Conclusions: Our new extrapedicular screw placement method into the vertebral body provides an easy, accurate, and safe alternative for scoliosis patients with ESLPs without relying on the O-arm navigation system. Surgeons must consider utilizing this method to enhance correction power in scoliosis surgery, regardless of the small size of the lumbar pedicle.

A simplified cranial cavity model to understand the relationship between intracranial pressure and dural sinus pressure

Although accurate intracranial pressure (ICP) monitoring is essential for the diagnosis and treatment of severe brain diseases, current methods are performed invasively. Therefore, a safe and less invasive ICP measurement is required. The purpose of our study was to develop a simplified cranial cavity model for a better understanding of the relationship between the ICP and the pressure measurement within the dural venous sinus (DVS) to support the validity of using sinus pressure as the surrogate of the ICP. The in-house cranial cavity model had three components: the brain part, the DVS part, and the subarachnoid space (SAS) part. Pressure in other parts was measured when the pressure in the SAS part and, separately, brain part was increased from 0 (baseline) to 50 mmHg at intervals of 10 mmHg. When the pressure in the SAS part was increased from 10 to 50 mmHg at 10 mmHg interval, pressures of both the brain and DVS parts increased without significant difference (all P > 0.05). However, pressures in both the SAS and DVS parts differed while the pressure in the brain part was increased. The pressures in both parts showed about 70% of the increase in the brain part. Nevertheless, the pressures in the SAS and DVS parts were not significantly different (P > 0.05). A simplified in-house cranial cavity model was developed consisting of three compartments to represent the actual intracranial spaces. The pressure measurement within the DVS was feasible to use as a surrogate for the ICP measurement.

Connecting the S2 alar-iliac screw head to the satellite rod for surgical correction of degenerative sagittal imbalance

PURPOSE

The S2AI screw technique has several advantages over the conventional iliac screw fixation technique. However, connecting the S2AI screw head to the main rod is difficult due to its medial entry point. We introduce a new technique for connecting the S2AI screw head to a satellite rod and compare it with the conventional method of connecting the S2AI screw to the main rod.

METHODS

Seventy-four patients who underwent S2AI fixation for degenerative sagittal imbalance and were followed up for ≥ 2 years were included. All the patients underwent long fusion from T9 or T10 to the pelvis. The S2AI screw head was connected to the satellite rod (SS group) in 43 patients and the main rod (SM group) in 31 patients. In the SS group, the satellite rod was placed medial to the main rod and connected by the S2AI screw and domino connectors. In the SM group, the main rod was connected directly to the S2AI screw head and supported by accessory rods. Radiographic and clinical outcomes were evaluated in both groups.

RESULTS

There were no significant differences in postoperative complications, including proximal junctional failure, proximal junctional kyphosis, rod breakage, screw loosening, wound problems, and infection between the two groups. Furthermore, the correction power of sagittal deformity and clinical results in the SS group were comparable to those in the SM group.

CONCLUSION

Connecting the S2AI screw to the satellite rod is a convenient method comparable to the conventional S2AI connection method in terms of radiological and clinical outcomes.

Effectiveness of next-generation sequencing for patients with advanced non-small-cell lung cancer: a population-based registry study

BACKGROUND

Despite the growing use of next-generation sequencing (NGS) in the management of advanced non-small-cell lung cancer (NSCLC), there is little evidence that its use leads to improved clinical outcomes. This study aimed to compare the effectiveness of NGS with that of single-gene testing (SGT) alone in patients with advanced NSCLC.

MATERIALS AND METHODS

This was a retrospective cohort study conducted on patients diagnosed with advanced lung adenocarcinoma between 2017 and 2018 from a nationwide, population-based database. We identified patients who had SGT exclusively (SGT group) or underwent upfront NGS or NGS following SGT as an initial evaluation (NGS group). Patients were followed up until death or the end of the study (31 December 2019). The adjusted hazard ratio (aHR) for death was estimated using the Cox proportional hazards model. The factors affecting the adoption of NGS were identified.

RESULTS

Of 8566 patients diagnosed with advanced lung adenocarcinoma, 402 and 6932 patients were assigned to the NGS and SGT groups, respectively. More NGS was carried out in younger patients, those with higher incomes, and those living in urban areas. After balancing these confounders through matching, no difference was observed in the median overall survival and risk of death between the NGS and SGT groups [18.5 versus 19.7 months, log-rank P = 0.783; aHR 0.98, 95% confidence interval (CI) 0.84-1.14, respectively]. Only in a subgroup for whom epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitors were not indicated, NGS was associated with better survival outcomes (14.1 versus 9.0 months, log-rank P = 0.006; aHR 0.82, 95% CI 0.69-0.97).

CONCLUSIONS

In the real world, NGS for all-comers in patients with advanced NSCLC did not increase survival outcomes. When health care resources to support equal access to NGS are limited, upfront SGT followed by NGS may be a more efficient strategy.

Subcutaneous leiomyosarcoma in a cynomolgus macaque (Macaca fascicularis)

Leiomyosarcoma, a malignant tumour originating from smooth muscle cells, has rarely been documented in non-human primates. In this case study, a 7-year-old female cynomolgus macaque (Macaca fascicularis) presented with a rapidly growing mass overlying the left elbow joint. Radiographs indicated the presence of a soft tissue neoplasm without any associated bone involvement. The mass was surgically resected. Histological and immunohistochemical analyses revealed spindle-shaped cells with eosinophilic cytoplasm that resembled smooth muscle cells, exhibiting positive immunoreactions for vimentin, desmin and smooth muscle actin and a negative reaction for pan-cytokeratin. This is the first reported case of subcutaneous leiomyosarcoma in a cynomolgus macaque and provides important insights into the incidence and characteristics of this condition in this species.

Can We Control Lateral Shoulder Balance Through Proximal Thoracic Curve Correction in Lenke Type 2 Adolescent Idiopathic Scoliosis?

BACKGROUND

Proximal thoracic curve (PTC) correction has been considered to prevent lateral shoulder imbalance in Lenke Type 2 adolescent idiopathic scoliosis (AIS) patients; however, postoperative shoulder imbalance (PSI) commonly occurs despite these strategies with PTC correction. We investigated the hypothesis that PTC correction would not directly affect PSI in the majority of Lenke type 2 AIS cases. Furthermore, we investigated the risk factors for lateral PSI after corrective surgery.

METHODS

This study examined the records for AIS patients with Lenke type 2 who underwent corrective surgery and followed up for >2 years. Patients were categorized into PSI (-); radiologic shoulder height (RSH)<15 mm, and PSI (+); RSH≥15 mm. Repeated measures analysis of variance was performed at preoperatively, postoperatively, 1 month, and final follow-up. Postoperative lateral shoulder imbalance was predicted by the identification of univariate analysis and multivariate analysis.

RESULTS

Among the 151 patients reviewed, 29 (19.2%) showed PSI at final follow-up. Lateral shoulder balance parameters showed different directionalities between PSI (-) and (+) groups at postoperatively, 1 month, and final follow-up ( P <0.01 each). Preoperative PTC, middle thoracic curve (MTC) curve and MTC correction showed strong correlations with the RSH ( P =0.01, 0.03, and 0.04, respectively). However, PTC correction did not show a significant correlation with the RSH. Moreover, only a smaller MTC curve and larger MTC correction rate were related to lateral PSI in multivariate analysis.

CONCLUSIONS

In Lenke type 2 AIS curves, the MTC curve and its correction predominantly influence lateral shoulder imbalance after corrective surgery, irrespective of the PTC correction extent. Consequently, overemphasizing the correction of the PTC curve may not necessarily lead to an improved lateral shoulder balance. When MTC curve is smaller, surgeons should be more careful for MCT overcorrection leading to a lateral shoulder imbalance.

LEVEL OF EVIDENCE

Level III.

Improved diagnostic performance of susceptibility-weighted imaging with compressed sensing-sensitivity encoding and neuromelanin-sensitive MRI for Parkinson's disease and atypical Parkinsonism

AIM

To verify the diagnostic performance of the loss of nigrosome-1 on susceptibility-weighted imaging (SWI) with compressed sensing-sensitivity encoding (CS-SENSE) and neuromelanin on neuromelanin-sensitive (NM) magnetic resonance imaging (MRI) for the diagnosis of Parkinson's disease (PD) and atypical Parkinsonism.

MATERIALS AND METHODS

A total of 195 patients who underwent MRI between October 2019 and February 2020, including SWI, with or without CS-SENSE, and NM-MRI, were reviewed retrospectively. Two neuroradiologists assessed the loss of nigrosome-1 on SWI and neuromelanin on the NM-MRI. The result of N-3-fluoropropyl-2-beta-carbomethoxy-3-beta-(4-iodophenyl) nortropane positron-emission tomography (PET) was set as the reference standard.

RESULTS

When CS-SENSE was applied for nigrosome-1 imaging on SWI, the non-diagnostic scan rate was lowered significantly from 19.3% (17/88) to 5.6% (6/107; p=0.004). Diagnosis of PD and atypical Parkinsonism based on the loss of nigrosome-1 on SWI and based on NM-MRI showed good diagnostic value (area under the curve [AUC] 0.821, 95% confidence interval [CI] = 0.755-0.875: AUC 0.832, 95% CI = 0.771-0.882, respectively) with a substantial inter-reader agreement (κ = 0.791 and 0.681, respectively). Combined SWI and neuromelanin had a similar discriminatory ability (AUC 0.830, 95% CI = 0.770-0.880). Similarly, the diagnosis of PD was excellent.

CONCLUSIONS

CS-SENSE may add value to the diagnostic capability of nigrosome-1 on SWI to reduce the nondiagnostic scan rates. Furthermore, loss of nigrosome-1 on SWI or volume loss of neuromelanin on NM-MRI may be helpful for diagnosing PD.

An Algorithmic Roadmap for Surgical Management of Degenerative Cervical Myelopathy: A Narrative Review

Degenerative cervical myelopathy (DCM) is a leading cause of disability, with its surgical management being crucial for patient neurological outcomes. Given the varied presentations and severities of DCM, treatment options are diverse. Surgeons often face challenges in selecting the most appropriate surgical approach, as there is no universally correct answer. This narrative review aims to aid the decision-making process in treating DCM by presenting a structured treatment algorithm. The authors categorized surgical scenarios based on an algorithm, outlining suitable treatment methods for each situation. Four primary scenarios were identified based on the number of levels requiring surgery and K-line status: (1) K-line (+) and ≤ 3 levels, (2) K-line (+) and ≥ 3 levels, (3) K-line (-) and ≤ 3 levels, and (4) K-line (-) and ≥ 3 levels. This categorization aids in determining the appropriateness of anterior or posterior approaches and the necessity for fusion, considering the surgical levels and K-line status. The complexity of surgical situations and the diversity of treatment methods for DCM can be effectively managed by utilizing an algorithmic approach. Furthermore, surgical techniques that minimize stages and address challenging conditions could potentially enhance outcomes in DCM treatment.

Seasonal occurrence of bark and woodboring Coleoptera in stands of Pinus densiflora (Pinales: Pinaceae) and Larix kaempferi (Pinales: Pinaceae) and monitoring method using multifunnel traps baited with pine volatiles

This study investigated the seasonal occurrence of bark and woodboring Coleoptera in Pinus densiflora (Pinales: Pinaceae), and Larix kaempferi (Pinales: Pinaceae) stands using multifunnel traps baited with pine volatiles in Korea. The number and species of bark and woodboring beetles caught in traps baited with ethanol, α-pinene, and ethanol+α-pinene were compared to determine the effective attractants. In addition, the effects of other pine volatiles, such as (-)-β-pinene, β-caryophyllene, (±)-limonene, β-myrcene, and 3-carene, were investigated. A total of 13,134 woodboring beetles from 150 species were collected from pine and larch stands from 2019 to 2020. Tomicus minor (Hartig) (Coleoptera: Curculionidae) adults were more attracted to traps baited with α-pinene, whereas Xyleborinus saxesenii (Ratzeburg) (Coleoptera: Curculionidae), Cyclorhipidion pelliculosum (Eichhoff) (Coleoptera: Curculionidae), and Phloeosinus pulchellus (Blandford) (Coleoptera: Curculionidae) adults were more attracted to traps baited with ethanol. Hylurgops interstitialis (Chapuis) (Coleoptera: Curculionidae), Shirahoshizo genus group, Rhagium inquisitor (Linne) (Coleoptera: Cerambycidae), and Rhadinomerus maebarai (Voss & Chûjô) (Coleoptera: Curculionidae) were more frequently attracted to traps baited with ethanol+α-pinene than to traps baited with other attractants. The addition of 3-carene to ethanol+α-pinene enhanced the capture of H. interstitialis, R. inquisitor, and Hylobius (Callirus) haroldi (Faust) (Coleoptera: Curculionidae).

Risk Factors for Postoperative Loss of Lordosis, Cervical Kyphosis, and Sagittal Imbalance After Cervical Laminoplasty

OBJECTIVE

A retrospective cohort study was undertaken to elucidate the risk factors of loss of cervical lordosis (LCL), kyphotic deformity, and sagittal imbalance after cervical laminoplasty.

METHODS

A total of 108 patients who underwent laminoplasty to treat cervical myelopathy and were followed for ≥2 years were included. Logistic regression analysis and multiple regression analysis were performed to identify preoperative risk factors of LCL, kyphotic deformity (cervical lordosis <0°), and sagittal imbalance (sagittal vertical axis >40 mm) at postoperative 2 years.

RESULTS

Within multivariate multiple regression analysis, C2-C7 lordosis (P = 0.002), and C2-C7 extension capacity (P<0.001) showed significant association with LCL. Furthermore, age (P = 0.043) and C2-C7 lordosis (P = 0.038) were significantly associated with postoperative kyphosis. Receiver operating characteristic curve analysis for postoperative kyphosis showed that preoperative C2-C7 lordosis of 10.5° had a sensitivity and specificity of 81.3% and 82.4%, respectively. Preoperative K-line tilt (P = 0.034) showed a significant association with postoperative cervical sagittal imbalance at postoperative 2 years. Receiver operating characteristic curve analysis showed that a K-line tilt cutoff value of 12.5° had a sensitivity and specificity of 78.6% and 77.7%, respectively, for predicting postoperative sagittal imbalance.

CONCLUSIONS

Higher preoperative C2-C7 lordosis and less preoperative cervical extension capacity were risk factors of LCL. Small preoperative C2-C7 lordosis <10.5° and younger age were risk factors of postoperative kyphosis. Furthermore, a greater K-line tilt would increase the risk of postoperative sagittal imbalance, with a cutoff value of 12.5°.

Fate of pseudarthrosis detected 2 years after anterior cervical discectomy and fusion: results of a minimum 5-year follow-up

BACKGROUND CONTEXT

Prior study has shown that 70% of cervical pseudarthrosis after anterior cervical discectomy and fusion (ACDF) detected at 1 year will go on to fusion by 2 year. Pseudarthrosis detected 2 years after ACDF may have different bone healing potential compared to nonunion detected 1 year after surgery. Therefore, it might have a different clinical significance.

PURPOSE

To examine the radiographic and clinical prognosis of pseudarthrosis detected 2 years after ACDF with a minimum follow-up of 5 years.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENTS SAMPLE

A total of 249 patients who completed a 5-year follow-up after ACDF.

OUTCOMES MEASURES

Clinical outcomes such as neck pain visual analogue scale (VAS), arm pain VAS, and neck disability index (NDI) and radiographic assessment such as X-ray, computed tomography (CT) scan.

METHODS

A total of 249 patients who completed a 5-year follow-up after ACDF were retrospectively reviewed. Patients who were diagnosed with pseudarthrosis at 2 years postoperatively were included. Fusion, neck pain VAS, arm pain VAS, and NDI were assessed. The results were compared between the union group (patients who achieved union), and the nonunion group (patients with pseudarthrosis) at 5 years postoperatively.

RESULTS

Among the patients who had pseudarthrosis at 2 years postoperatively, the fusion rate at 5 years was 32.6% (14/43). While the union group showed continued improvements in neck pain VAS, arm pain VAS, and NDI until 5 years, the nonunion group showed significant worsening of arm pain VAS and NDI at 5 years, with the values of neck pain VAS, arm pain VAS, and NDI being significantly worse than those of the union group at 5 years.

CONCLUSION

The incidence of pseudarthrosis detected at 2 years postoperatively after ACDF was 67.4%, and it remained unfused at 5 years postoperatively. Nonunion identified 2 years after ACDF may be considered a poor prognostic factor because it has less potential to achieve fusion with further follow-up and a higher chance of worsening clinical symptoms. Therefore, the presence of fusion at the 2-year follow-up can be considered an indicator of the success of the surgery.

Search for Boosted Dark Matter in COSINE-100

We search for energetic electron recoil signals induced by boosted dark matter (BDM) from the galactic center using the COSINE-100 array of NaI(Tl) crystal detectors at the Yangyang Underground Laboratory. The signal would be an excess of events with energies above 4 MeV over the well-understood background. Because no excess of events are observed in a 97.7  kg·yr exposure, we set limits on BDM interactions under a variety of hypotheses. Notably, we explored the dark photon parameter space, leading to competitive limits compared to direct dark photon search experiments, particularly for dark photon masses below 4 MeV and considering the invisible decay mode. Furthermore, by comparing our results with a previous BDM search conducted by the Super-Kamionkande experiment, we found that the COSINE-100 detector has advantages in searching for low-mass dark matter. This analysis demonstrates the potential of the COSINE-100 detector to search for MeV electron recoil signals produced by the dark sector particle interactions.

Does Posterior Cord Compression From the Ligamentum Flavum Influence Clinical Outcomes After Anterior Cervical Discectomy and Fusion?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To clarify whether outcomes of anterior cervical discectomy and fusion (ACDF) differ according to the presence of posterior cord compression from the ligamentum flavum (CCLF).

SUMMARY OF BACKGROUND DATA

Although ACDF effectively addresses anterior cord compression from disc material and bone spurs, it cannot address posterior compression. Whether ACDF could result in favorable outcomes when CCLF is present remains unclear.

PATIENTS AND METHODS

A total of 195 consecutive patients who underwent ACDF and were followed up for >2 years were included. CCLF was graded based on magnetic resonance imaging findings. Patients with CCLF grade 2 were classified as such, whereas patients with CCLF grades 0 to 1 were classified as the no-CCLF group. Patient characteristics, cervical sagittal parameters, neck pain visual analog scale, arm pain visual analog scale, and Japanese Orthopedic Association (JOA) score were assessed. Categorical variables were analyzed using a χ 2 test, whereas continuous variables were analyzed using the Student t test. Multivariable logistic regression analysis was performed to elucidate factors associated with JOA recovery rates of >50%.

RESULTS

One hundred sixty-seven patients (85.6%) were included in the no-CCLF group, whereas the remaining 28 patients (14.4%) were included in the CCLF group. Among patients in the CCLF group, 14 patients (50.0%) achieved clinical improvement. JOA score significantly improved in the no-CCLF group after the operation ( P < 0.001), whereas improvement was not appreciated in the CCLF group ( P = 0.642). JOA scores at 3 months ( P = 0.037) and 2 years ( P = 0.001) postoperatively were significantly higher in the no-CCLF group. Furthermore, the JOA recovery rate at 2 years after surgery was significantly higher in the no-CCLF group ( P = 0.042). Logistic regression demonstrated that CCLF was significantly associated with a JOA recovery rate of >50% at 2 years after surgery (odds ratio: 2.719; 95% CI: 1.12, 6.60).

CONCLUSION

ACDF performed for patients with CCLF grade 2 showed inferior JOA score improvement compared with those with CCLF grade 0 or 1. ACDF cannot remove posterior compressive structures, which limits its utility when ligamentum flavum significantly contributes to cord compression.

Spiral-phase-objective for a compact spiral-phase-contrast microscopy

Spiral-phase-contrast imaging, which utilizes a spiral phase optical element, has proven to be effective in enhancing various aspects of imaging, such as edge contrast and shadow imaging. Typically, the implementation of spiral-phase-contrast imaging requires the formation of a Fourier plane through a 4f optical configuration in addition to an existing optical microscope. In this study, we present what we believe to be a novel single spiral-phase-objective, integrating a spiral phase plate, which can be easily and simply applied to a standard microscope, such as a conventional objective. Using a new hybrid design approach that combines ray-tracing and field-tracing simulations, we theoretically realized a well-defined and high-quality vortex beam through the spiral-phase-objective. The spiral-phase-objective was designed to have conditions that are practically manufacturable while providing predictable performance. To evaluate its capabilities, we utilized the designed spiral-phase-objective to investigate isotropic spiral phase contrast and anisotropic shadow imaging through field-tracing simulations, and explored the variation of edge contrast caused by changes in the thickness of the imaging object.

Clinical outcomes of sinonasal inverted papilloma: a retrospective analysis of 139 cases

OBJECTIVES

Sinonasal inverted papilloma has a high tendency for recurrence, local bone destruction and risk of malignant transformation. Therefore, complete resection of the tumour is required, and close follow up is essential. This article describes the clinical outcomes, recurrence rate and malignant transformation rate of sinonasal inverted papilloma.

METHODS

In this study, 139 patients diagnosed with sinonasal inverted papilloma in our hospital from December 2010 to May 2022 were retrospectively analysed. All patients underwent endoscopic surgery.

RESULTS

Sinonasal inverted papilloma occurred more often in males than in females. The mean age of patients with sinonasal inverted papilloma was 67.3 ± 5.7 years at diagnosis. The most prevalent site of origin was the maxillary sinus (50.4 per cent). The recurrence rate was 5.75 per cent, and the malignant transformation rate was 6.5 per cent.

CONCLUSION

All patients in this study underwent endoscopic surgery. Meticulous resection and regular long-term follow ups are crucial to reducing sinonasal inverted papilloma recurrence after surgery.

Surgical complications and incomplete canal widening of the vertebral body sliding osteotomy to treat cervical myelopathy

OBJECTIVE

Vertebral body sliding osteotomy (VBSO) is a surgical technique that anteriorly translates the vertebral body with compressive lesions and achieves cord decompression through canal widening. However, data on the surgical complications of VBSO are lacking. Furthermore, it has not been known whether VBSO could be a viable alternative in the treatment of cervical myelopathy even when the preoperative canal-occupying ratio (COR) is large, which seems to frequently result in incomplete canal widening. This study aimed to describe the incidence of VBSO-associated surgical complications and to evaluate the incidence and risk factors of incomplete canal widening.

METHODS

A total of 109 patients who underwent VBSO to treat cervical myelopathy were retrospectively reviewed. Neck pain visual analog scale, Neck Disability Index, Japanese Orthopaedic Association (JOA) scores, and surgical complications were evaluated. For radiological evaluation, C2-7 lordosis, C2-7 sagittal vertical axis, and COR were measured. Patients with a preoperative COR < 50% (n = 60) and those with a COR ≥ 50% (n = 49) were compared and logistic regression analysis was performed to identify factors associated with incomplete canal widening.

RESULTS

The most frequent complication in the patients was mild dysphagia (7.3%). Dural tears were observed during posterior longitudinal ligament resection (n = 1) and foraminotomy (n = 1). Two patients underwent reoperation due to radiculopathy from adjacent-segment disease. Incomplete canal widening occurred in 49 patients. According to logistic regression analysis, high preoperative COR was the only factor associated with incomplete canal widening. The amount of canal widening and JOA recovery rate in the COR ≥ 50% group were significantly higher than in the COR < 50% group.

CONCLUSIONS

Mild dysphagia was the most common complication following VBSO. Although VBSO aims to decrease the complication rate of corpectomy, it was not free of dural tears. Special care would be required during the posterior longitudinal ligament resection. Incomplete canal widening occurred in 45.0% of patients, and high preoperative COR was the only risk factor for incomplete canal widening. However, high preoperative COR would not be a contraindication for VBSO, given that favorable clinical outcomes were presented in the COR ≥ 50% group.

Foraminal Restenosis After Posterior Cervical Foraminotomy for the Treatment of Cervical Radiculopathy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To elucidate incidence, risk factor, and clinical effect of bone regrowth after posterior cervical foraminotomy (PCF).

METHODS

Ninety-eight patients who underwent PCF for the treatment of cervical radiculopathy and were followed up for >2 years were retrospectively reviewed. Foraminal dimension, sagittal gap at resected area, facet thickness, lamina length, and cervical range of motion (ROM) were measured. Neck pain visual analogue scale (VAS), arm pain VAS, and neck disability index (NDI) were recorded. Radiographic measures were compared between segments with foraminal narrowing of ≥20% at the 2-years follow-up (restenosis segments) and foraminal narrowing of <20% (patent segments).

RESULTS

Sixty-nine patients with 109 segments were included. 73.4% (80/109) of foramens demonstrated foraminal narrowing and decrease of foraminal dimension of ≥20% occurred in 30.3% (30/109). Foraminal dimension at postoperative 2-days was significantly higher in the restenosis segments (P = .047). Furthermore, increase of foraminal dimension was significantly associated with foraminal restenosis of ≥20% (P = .018). Facet thickness was significantly higher in the restenosis segments compared to patent segments at postoperative 2-years follow-up (P = .038). Neck pain VAS was significantly aggravated only in the restenosis group at postoperative 2-years follow-up (P < .001).

CONCLUSIONS

Foraminal narrowing commonly occurs after PCF due to bone healing. Bone growth occurs in all directions while medial facet growth contributes more to foraminal restenosis. Greater widening of foramen during PCF is a risk factor for postoperative foramen restenosis. Therefore, amount of bone resection should be kept optimal and excessive resection should be avoided to prevent foramen restenosis.

Atrophy of the Posterior Cricoarytenoid Muscle as an Indicator of a Recurrent Laryngeal Nerve Injury History Before Revision Anterior Cervical Spine Surgery

STUDY DESIGN

Retrospective study.

OBJECTIVES

In our recent study, we observed some cases of symptomatic normal vocal cord motility instead of asymptomatic vocal cord palsy (VCP) in preoperative laryngoscopy of a revision anterior cervical spine surgery (ACSS) cohort. We assumed the intrinsic muscle atrophy caused by recurrent laryngeal nerve injury could cause vocal cord-related symptoms. Thus, radiological examinations were reviewed in relation to the posterior cricoarytenoid (PCA) muscle, one of the intrinsic muscles.

METHODS

We retrospectively analyzed 64 patients who underwent a revision ACSS. Patients with vocal cord-related symptoms were classified as symptomatic group (group S, n = 11), and those without symptoms as asymptomatic group (group AS, n = 53). The bilateral size and signal intensity of the PCA muscles in these patients were measured in the axial view with preoperative computed tomography (CT) and magnetic resonance imaging (MRI) evaluations. Since the size and signal intensity values were different on each image, the ratios of the contralateral and ipsilateral muscle values were analyzed for each modality.

RESULTS

There was no VCP on laryngoscopy study. However, the mean ratio of the PCA muscle size on CT was 1.40 ± .37 in group S and 1.02 ± .12 in group AS (P = .007). These values on the MRI were 1.49 ± .45 in group S and 1.02 ± .14 in group AS, which was also a significant difference (P = .008).

CONCLUSIONS

Evaluating the size of the PCA muscle before revision ACSS may predict a previous recurrent laryngeal nerve injury. Careful planning for the appropriate approach should be undertaken if vocal cord-related symptoms and atrophy of PCA muscle are evident.

Relationship Between C2 Semispinalis Cervicis Preservation and C2 Spinous Process Morphology During Cervical Laminoplasty Involving C3

STUDY DESIGN

Retrospective study.

OBJECTIVES

Due to anatomical variations in the semispinalis cervicis insertion in the C2 spinous process, complete preservation is not always possible when the C3 level is included in a cervical laminoplasty. Three-dimensional computed tomography was used to evaluate the relationship between the incidence of semispinalis cervicis injury and the C2 inter-spinous angle.

METHODS

We included 95 patients who underwent a cervical laminoplasty that included a C3 laminectomy for cervical myelopathy. Patients with a C2 inter-spinous angle above and below 60° were classified into wide- and narrow-angled groups, respectively (n = 48 and n = 47). Whether the C2 semispinalis cervicis insertion was preserved, or detached and reattached was reviewed from surgical records. The pre and postoperative C2-C7 lordosis and range of motion (ROM) were measured, and clinical outcomes were obtained from the patient charts.

RESULTS

The C2 semispinalis cervicis was preserved in 47 patients (97.9%) in the wide-angled group but only in 14 patients (29.8%) in the narrow-angled group (P < .001). The postoperative C2-C7 lordosis extension and ROM were significantly greater in the wide-angled (P = .048 and .036). Postoperative neck pain was significantly greater in the narrow-angled (P = .018).

CONCLUSIONS

The morphology of the C2 spinous process indicates that a C2 semispinalis cervicis insertion preservation is possible during a cervical laminoplasty that includes a C3 laminectomy. A careful surgical procedure should be conducted when the C2 inter-spinous angle is above 60° to increase the likelihood of achieving this preservation and thereby obtaining a more favorable clinical outcomes.

Vertebral Body Sliding Osteotomy as a Surgical Strategy for the Treatment of Cervical Myelopathy: Complications and Pitfalls

OBJECTIVE

This retrospective cohort study has been aimed at evaluating the incidence of complications after vertebral body sliding osteotomy (VBSO) and analyzing some cases. Furthermore, the complications of VBSO were compared with those of anterior cervical corpectomy and fusion (ACCF).

METHODS

This study included 154 patients who underwent VBSO (n = 109) or ACCF (n = 45) for cervical myelopathy and were followed up for > 2 years. Surgical complications, clinical and radiological outcomes were analyzed.

RESULTS

The most common surgical complications after VBSO were dysphagia (n = 8, 7.3%) and significant subsidence (n = 6, 5.5%). There were 5 cases of C5 palsy (4.6%), followed by dysphonia (n = 4, 3.7%), implant failure (n = 3, 2.8%), pseudoarthrosis (n = 3, 2.8%), dural tears (n = 2, 1.8%), and reoperation (n = 2, 1.8%). C5 palsy and dysphagia did not require additional treatment and spontaneously resolved. The rates of reoperation (VBSO, 1.8%; ACCF, 11.1%; p = 0.02) and subsidence (VBSO, 5.5%; ACCF, 40%; p < 0.01) were significantly lower in VBSO than in ACCF. VBSO restored more C2-7 lordosis (VBSO, 13.9° ± 7.5°; ACCF, 10.1° ± 8.0°; p = 0.02) and segmental lordosis (VBSO, 15.7° ± 7.1°; ACCF, 6.6° ± 10.2°; p < 0.01) than ACCF. The clinical outcomes did not significantly differ between both groups.

CONCLUSION

VBSO has advantages over ACCF in terms of low rate of surgical complications related to reoperation and significant subsidence. However, dural tears may still occur despite the lessened need for ossified posterior longitudinal ligament lesion manipulation in VBSO; hence, caution is warranted.

Risk factors for postoperative complaints in patients following lumbar decompression and fusion: Analyses focusing on preoperative symptoms

BACKGROUND

Several patients complained of residual symptoms following lumbar decompressive surgery for lumbar degenerative disease (LDD). However, few studies analyze this dissatisfaction by focusing on preoperative patients' symptoms. This study was conduct to determine the factors that could predict the patients' postoperative complaints by focusing on their preoperative symptoms.

METHODS

Four hundred and seventeen consecutive patients who underwent lumbar decompression and fusion surgery for LDD were included. Postoperative complaint was defined by at least twice same complaint during the outpatient follow-up of 6,12, 18 and 24 months after surgery. A comparative analysis was performed between complaint group (group C, N = 168) and non-complaint group (group NC, N = 249). Demographic, operative, symptomatic, and clinical factors were compared between the groups by univariate and multivariate analyses.

RESULTS

The main preoperative chief complaints were radiating pain (318/417, 76.2%). However, most common postoperative complaint was residual radiating pain (60/168, 35.7%) followed by tingling sensation (43/168, 25.6%). The presence of psychiatric disease (adjusted odds ratio [aOR], 4.666; P = 0.017), longer pain duration (aOR, 1.021; P < 0.001), pain to below the knee (aOR, 2.326; P = 0.001), preoperative tingling sensation (aOR, 2.631; P < 0.001), preoperative sensory and motor power decrease (aOR, 2.152 and 1.678; P = 0,047 and 0.011, respectively) were significantly correlated with postoperative patients' complaints in multivariate analysis.

CONCLUSIONS

The postoperative patients' complaints could be predicted and explained in advance by checking the preoperative characteristics of patients' symptoms, including the duration and site carefully. This could be helpful to enhance the understanding of the surgical results preoperatively, which could control the anticipation of the patients.

A phase II open-label trial of avelumab plus axitinib in previously treated non-small-cell lung cancer or treatment-naïve, cisplatin-ineligible urothelial cancer

BACKGROUND

We hypothesized that avelumab plus axitinib could improve clinical outcomes in patients with advanced non-small-cell lung cancer (NSCLC) or urothelial carcinoma (UC).

PATIENTS AND METHODS

We enrolled previously treated patients with advanced or metastatic NSCLC, or untreated, cisplatin-ineligible patients with advanced or metastatic UC. Patients received avelumab 800 mg every 2 weeks (Q2W) and axitinib 5 mg orally two times daily. The primary endpoint was objective response rate (ORR). Immunohistochemistry was used to assess programmed death-ligand 1 (PD-L1) expression (SP263 assay) and the presence of CD8+ T cells (clone C8/144B). Tumor mutational burden (TMB) was assessed by whole-exome sequencing.

RESULTS

A total of 61 patients were enrolled and treated (NSCLC, n = 41; UC, n = 20); 5 remained on treatment at data cut-off (26 February 2021). The confirmed ORR was 31.7% in the NSCLC cohort and 10.0% in the UC cohort (all partial responses). Antitumor activity was observed irrespective of PD-L1 expression. In exploratory subgroups, ORRs were higher in patients with higher (≥median) CD8+ T cells in the tumor. ORRs were higher in patients with lower TMB (<median) in the NSCLC cohort and higher TMB (≥median) in the UC cohort. Treatment-related adverse events (TRAEs) occurred in 93.4% of patients, including grade ≥3 TRAEs in 55.7%. Avelumab exposures with 800 mg Q2W dosing were similar to those observed with 10 mg/kg Q2W dosing.

CONCLUSIONS

In previously treated patients with advanced/metastatic NSCLC, ORR appeared to be superior to anti-PD-L1 or anti-programmed cell death protein 1 monotherapy, irrespective of PD-L1 status, whereas in untreated, cisplatin-ineligible patients with advanced/metastatic UC, ORR was lower than expected, potentially limited by small patient numbers.

TRIAL REGISTRATION

Clinicaltrial.gov NCT03472560; https://clinicaltrials.gov/ct2/show/NCT03472560.

Acaricidal and Insecticidal Activities of Essential Oils and Constituents of Tasmannia lanceolata (Poir.) A.C.Sm. (Canellales: Winteraceae) Against Tetranychus urticae Koch (Trombidiformes: Tetranychidae) and Myzus persicae Sulzer (Hemiptera: Aphididae)

The negative side effects of synthetic pesticides have drawn attention to the need for environmentally friendly agents to control arthropod pests. To identify promising candidates as botanical pesticides, we investigated the acaricidal and insecticidal activities of 44 plant-derived essential oils (EOs) against Tetranychus urticae Koch and Myzus persicae Sulzer. Among the tested EOs, Tasmannia lanceolata (Poir.) A.C.Sm. (Tasmanian pepper) essential oil (TPEO) exhibited strong acaricidal and insecticidal activity. Mortality rates of 100% and 71.4% against T. urticae and M. persicae, respectively, were observed with TPEO at a concentration of 2 mg/ml. Polygodial was determined to be the primary active component after bioassay-guided isolation of TPEO using silica gel open-column chromatography, gas chromatography, and gas chromatography-mass spectrometry. Polygodial demonstrated acaricidal activity against T. urticae with mortality rates of 100%, 100%, 61.9%, and 61.6% at concentrations of 1, 0.5, 0.25, and 0.125 mg/ml, respectively. Insecticidal activity against M. persicae was also evident, with mortality rates of 88.5%, 85.0%, 46.7%, and 43.3% at respective concentrations of 1, 0.5, 0.25, and 0.125 mg/ml. Insecticidal and acaricidal activities of TPEO were greater than those of Eungjinssag, a commercially available organic agricultural material for controlling mites and aphids in the Republic of Korea. These findings suggest that TPEO is a promising candidate for mites and aphids control.

Superior limbic keratoconjunctivitis: Update on pathophysiology and management

Superior limbic keratoconjunctivitis (SLK) is an under-recognized condition characterized by a final common pathologic presentation of superior conjunctival and limbal inflammation and staining. Existing literature attributes both microtrauma and local inflammation, frequently in the setting of tear film insufficiency, as the underlying mechanisms that lead to a self-perpetuating pathologic process dependent in on inflammatory cells and signaling. Effective treatments act by targeting inflammation and by mitigating mechanical stressors. This critical review discusses the latest in our understanding of the pathophysiology of SLK and how it guides our treatment strategies.

Risk factors for the aggravation of sagittal balance after L5–S1 posterior lumbar interbody fusion

STUDY DESIGN

Retrospective comparative study OBJECTIVE: To identify the risk factors for the aggravation of sagittal alignment after single-level L5-S1 PLIF.

METHODS

Eighty-six patients who underwent L5-S1 PLIF were divided into two groups according to the postoperative changes in the segmental angle (SA; group I: increase; group D: decrease). The two groups were compared in terms of demographic, clinical, and radiological outcomes. Multivariate logistic regression analysis was performed to identify the risk factors for aggravation of sagittal alignment.

RESULTS

Of the study patients, 39 (45%) were categorized as group I and 47 (55%) as group D. The demographic and clinical parameters were not significantly different between the two groups. Group D showed postoperative deteriorations in the local sagittal parameters, including lumbar lordosis (LL; p=.034), sacral slope (p=.012), and pelvic tilt (p=.003). In contrast, group I showed improved LL after surgery (p=0.021). Large preoperative values of lumbosacral angle (LSA; odds ratio [OR], 1.287; p=.001), SA (OR, 1.448; p<.001), and flexion LSA (OR, 1.173; p=.011) were independent risk factors for the aggravation of sagittal balance.

CONCLUSIONS

Surgeons treating patients with large preoperative SA, LSA, and flexion LSA at L5-S1 level should be cautious of the possible aggravation of sagittal balance after L5-S1 PLIF and may consider different surgical approaches such as anterior or oblique lumbar interbody fusion.

Risk Factors and Exit Strategy of Intraoperative Neurophysiological Monitoring Alert During Deformity Correction for Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To elucidate the risk factors of intraoperative neurophysiological monitoring (IONM) alert during deformity correction surgery for adolescent idiopathic scoliosis (AIS) and to describe the outcomes of patients who underwent staged correction surgery due to IONM alert during the initial procedure.

METHODS

We reviewed 1 024 patients with idiopathic scoliosis who underwent deformity correction and were followed-up for ≥1 year. The pre-and postoperative Cobb angle of the major structural curve, operative time, estimated blood loss (EBL), number of levels fused, event that caused the IONM alert, and intervention required for the recovery of the signal were recorded. Patients who received IONM alerts (alert group) and those who did not (non-alert group) during the operation were compared.

RESULTS

Compared to the non-alert group, the alert group had a significantly greater preoperative Cobb angle of the major structural curve (P < .001), number of levels fused (P = .003), operative time (P < .001), and EBL (P < .001). The percentage of correction did not significantly differ between the 2 groups (P = .348). Eight patients (.8%) underwent a staged operation because the IONM signal alert hindered correction of the deformity. The percentage of correction of patients who underwent staged operation was 64.9 ± 15.1%, and no permanent neurologic deficits occurred.

CONCLUSIONS

A greater magnitude of preoperative deformity and surgical extent increases the risk of cord injury identified by IONM alerts during correction of deformities in patients with AIS. However, in patients in whom the IONM alert cannot be recovered or reproduced by proceeding with deformity correction, surgeons can minimize the risk by aborting the initial procedure and completing the correction using staged operations.

Using Lordotic Cages at the L5-S1 Level Does Not Guarantee the Improvement of Sagittal Alignment in Patients Who Underwent Posterior Lumbar Interbody Fusion

Study Design

Retrospective comparative study.

Purpose

This study aimed to investigate the effects of the lordotic angle of cages on sagittal alignment in patients who underwent 1- or 2-level posterior lumbar interbody fusion (PLIF), including the L5-S1 level.

Overview of Literature

Few studies have addressed the effects of the lordotic angle of cages on regional and global sagittal balance in patients undergoing PLIF at the L5-S1 level.

Methods

Sixty-one patients who underwent 1- or 2-level PLIF, including the L5-S1 level, were divided into two groups based on the lordotic angle of cages (4° and 8° in 41 and 20 patients, respectively). Clinical and radiological parameters were compared. Correlation analyzes were performed to reveal the effect of flexibility and position of cages on the regional sagittal parameters.

Results

Pre- and postoperative clinical and radiological parameters were not different between the two groups. Although clinical outcomes improved postoperatively, sagittal parameters did not improve postoperatively in both groups. Patients who underwent 1-level PLIF at the L5-S1 level with the use of 8° cages showed no postoperative improvement (segmental angle: 16.1°-15.9°, p =0.140; lumbar lordosis: 44.8°-47.8°, p =0.740) of regional sagittal parameters. The degree of anterior location of cages showed a positive correlation with the postoperative restoration of the segmental angle (p =0.012 and p =0.050 at 1 and 2 years postoperatively, respectively).

Conclusions

Clinical and radiological outcomes based on the lordotic angle of cages were not different. Even with the use of 8° cages and regardless of the more anterior position of cages, sagittal alignment did not improve in cases involving the L5-S1 level. PLIF at the L5-S1 level should be used with caution because improvement in sagittal alignment did not occur.

Effects of genomic estimated breeding value and dietary energy to protein ratio on growth performance, carcass trait, and lipogenic gene expression in Hanwoo steer

"Genome-based precision feeding" is a concept that involves the application of customised diets to different genetic groups of cattle. We investigated the effects of the genomic estimated breeding value (gEBV) and dietary energy to protein ratio (DEP) on growth performance, carcass traits, and lipogenic gene expression in Hanwoo (Korean cattle) steers. Forty-four Hanwoo steers (BW = 636 kg, age = 26.9 months) were genotyped using the Illumina Bovine 50 K BeadChip. The gEBV was calculated using genomic best linear unbiased prediction. Animals were separated into high gEBV of marbling score or low-gMS groups based on the upper and lower 50% groupings of the reference population, respectively. Animals were assigned to one of four groups in a 2 × 2 factorial arrangement: high gMS/high DEP (0.084 MJ/g), high gMS/low DEP (0.079 MJ/g), low gMS/high DEP, and low gMS/low DEP. Steers were fed concentrate with a high or low DEP for 31 weeks. The BW tended to be higher (0.05 < P < 0.1) in the high-gMS groups compared to the low-gMS groups at 0, 4, 8, 12, and 20 weeks. The average daily gain (ADG) tended to be lower (P = 0.08) in the high-gMS group than in the low-gMS group. Final BW and measured carcass weight (CW) were positively correlated with the gEBV of carcass weight (gCW). The DEP did not affect ADG. Neither the gMS nor the DEP affected the MS and beef quality grade. The intramuscular fat (IMF) content in the longissimus thoracis (LT) tended to be higher (P = 0.08) in the high-gMS groups than in the low-gMS groups. The mRNA levels of lipogenic acetyl-CoA carboxylase and fatty acid binding protein 4 genes in the LT were higher (P < 0.05) in the high-gMS group than in the low-gMS group. Overall, the IMF content tended to be affected by the gMS, and the genetic potential (i.e., gMS) was associated with the functional activity of lipogenic gene expression. The gCW was associated with the measured BW and CW. The results demonstrated that the gMS and the gCW may be used as early prediction indexes for meat quality and growth potential of beef cattle.

Different effects of low muscle mass on the risk of non-alcoholic fatty liver disease and hepatic fibrosis in a prospective cohort

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and sarcopenia share insulin resistance as a common pathophysiology and have overlapping clinical manifestation of metabolic derangement; hence, it is difficult to differentiate the independent effect of sarcopenia on the development of NAFLD from concomitant metabolic disorders. Using a community-based prospective cohort study, the contributions of low muscle mass and genetic risk factors to the development of NAFLD and NAFLD-related hepatic fibrosis were investigated in the Korean population.

METHODS

This prospective community-based cohort study included 40-70-year-old adults, followed up biennially from 2001-2002 to 2017-2018. NAFLD was defined as a hepatic steatosis index of ≥36, and hepatic fibrosis was defined based on the fibrosis-4 index. Sex-specific quartiles of body mass index (BMI)-adjusted muscle mass were calculated (muscle mass/BMI), and low muscle mass was defined as the lowest quartile (Q1). Cox proportional hazard models for incident NAFLD or hepatic fibrosis incorporating age, sex, BMI of ≥25 kg/m² , metabolic syndrome and PNPLA3 and TM6SF2 risk alleles were used to assess the independent determinants for incident NAFLD and hepatic fibrosis among individuals with NAFLD at baseline.

RESULTS

Among the 4038 participants without NAFLD at baseline (mean age, 51.5 ± 8.8 years), 920 (22.8%) developed NAFLD during the 12-year follow-up period. As muscle mass decreased, the risk of NAFLD increased even after adjustment for age, sex, obesity, metabolic syndrome and PNPLA3 and TM6SF2 risk alleles [hazard ratio (HR) per quartile, 1.18, 95% confidence interval (CI), 1.11-1.27, P < 0.001]. TM6SF2 also affected the risk of NAFLD development [HR 1.19, (95% CI, 1.00-1.40), P = 0.044]. Of the 1176 patients with NAFLD but without hepatic fibrosis at baseline, the incident of hepatic fibrosis was found in 51.8%, 44.7%, 42.6% and 41.0% in Q1, Q2, Q3 and Q4 of BMI-adjusted muscle mass, respectively, during the follow-up period (P for trend = 0.006). However, this trend lost its statistical significance when adjusted for confounders. The PNPLA3 risk variant, but not the TM6SF2 genotype, was an independent risk factor for developing hepatic fibrosis among patients with NAFLD (HR 1.17, 95% CI 1.04-1.32, P = 0.010).

CONCLUSIONS

Both lower muscle mass index and genetic risk variants are important contributors to the development of NAFLD. In patients already diagnosed with NAFLD, however, PNPLA3 confers a greater risk for hepatic fibrosis progression than lower muscle mass.

Predictable factors for aggravation of cervical alignment after posterior cervical foraminotomy

OBJECTIVE

This study aimed to investigate the risk factors for aggravation of cervical alignment after posterior cervical foraminotomy (PCF) and to identify their relationships with kyphotic changes in cervical curvature.

METHODS

Ninety-eight patients who underwent PCF for unilateral radiculopathy and received follow-up for more than 2 years were retrospectively reviewed. Segmental Cobb angle (SA), cervical Cobb angle (CA), Pfirrmann grade, foraminal stenosis, and clinical outcomes including neck pain, arm pain, and Neck Disability Index scores were assessed. Radiological and clinical outcomes were compared between groups C (control group with kyphotic change in CA < 5°) and K (kyphotic group with kyphotic change in CA ≥ 5°). Multivariate regression analysis was performed to determine the risk factors for kyphotic change ≥ 5° after PCF.

RESULTS

Group K was significantly older than group C (p = 0.002) and had a higher Pfirrmann grade (p = 0.025). In group K, neck pain had significantly increased at last follow-up (p < 0.001). Multivariate linear regression analysis revealed that kyphotic changes in CA were related to older age (p = 0.016, B = 0.420) and Pfirrmann grade of the operative levels (p = 0.032, B = 4.560). Preoperative hypolordosis was not an independent risk factor for kyphotic changes in CA. Receiver operating characteristic curve analysis showed that the cutoff value for kyphotic changes in patients with CA ≥ 5° was Pfirrmann grade 3.417 (p = 0.008).

CONCLUSIONS

Contrary to previous studies, preoperative hypolordosis was not a risk factor for kyphotic changes in CA after PCF. Older patients with disc degeneration of Pfirrmann grade IV or greater for should be carefully considered.

Efficacy and safety of oblique posterior endplate resection for wider decompression (trumpet-shaped decompression) during anterior cervical discectomy and fusion

OBJECTIVE

Anterior cervical discectomy and fusion (ACDF) provides a limited workspace, and surgeons often need to access the posterior aspect of the vertebral body to achieve sufficient decompression. Oblique resection of the posterior endplate (trumpet-shaped decompression [TSD]) widens the workspace, enabling removal of lesions behind the vertebral body. This study was conducted to evaluate the efficacy and safety of oblique posterior endplate resection for wider decompression.

METHODS

In this retrospective study, 227 patients who underwent ACDF for the treatment of cervical myelopathy or radiculopathy caused by spondylosis or ossification of the posterior longitudinal ligament and were followed up for ≥ 1 year were included. Patient characteristics, fusion rates, subsidence, and patient-reported outcome measures, including the neck pain visual analog scale (VAS) score, arm pain VAS score, and Neck Disability Index (NDI), were assessed. Patients who underwent TSD during ACDF (TSD group) and those who underwent surgery without TSD (non-TSD group) were compared.

RESULTS

Fifty-seven patients (25.1%) were included in the TSD group and 170 patients (74.9%) in the non-TSD group. In the TSD group, 28.2% ± 5.5% of the endplate was resected, and 26.0% ± 6.1% of the region behind the vertebral body could be visualized via the TSD technique. The resection angle was 26.9° ± 5.9°. The fusion rate assessed on the basis of interspinous motion, intragraft bone bridging, and extragraft bone bridging did not significantly differ between the two groups. Furthermore, there were no significant intergroup differences in subsidence. The patient-reported outcome measures at the 1-year follow-up were also not significantly different between the groups.

CONCLUSIONS

TSD widened the workspace during ACDF, and 26% of the region posterior to the vertebral body could be accessed using this technique. The construct stability was not adversely affected by TSD as demonstrated by the similar fusion and subsidence rates among patients who underwent TSD and those who did not. Therefore, TSD can be safely applied during ACDF when compressive lesions extend behind the vertebral body and are not limited to the disc space, enabling adequate decompression without disrupting the construct stability.

Anterior Decompression and Fusion for the Treatment of Cervical Myelopathy Caused by Ossification of the Posterior Longitudinal Ligament: A Narrative Review

Occasionally, ossification of the posterior longitudinal ligament (OPLL) causes cord compression, resulting in cervical myelopathy. OPLL differs from other causes of cervical spondylotic myelopathy in several ways, and the surgical strategy should be chosen with OPLL's characteristics in mind. Although both the anterior and posterior approaches are effective surgical methods for the treatment of OPLL cervical myelopathy, they each have their own set of benefits and drawbacks. Anterior decompression and fusion (ADF) may improve neurological recovery, restore lordosis, and prevent OPLL mass progression. The benefits can be seen in patients with a high canal occupying ratio or kyphotic alignment. We discussed the benefits, limitations, indications, and surgical techniques of ADF for the treatment of OPLL-induced cervical myelopathy in this narrative.

Artificial intelligence-estimated biological heart age using a 12-lead electrocardiogram predicts mortality and cardiovascular outcomes

Background

There is a paucity of data on artificial intelligence-estimated biological electrocardiography (ECG) heart age (AI ECG-heart age) for predicting cardiovascular outcomes, distinct from the chronological age (CA). We developed a deep learning-based algorithm to estimate the AI ECG-heart age using standard 12-lead ECGs and evaluated whether it predicted mortality and cardiovascular outcomes.

Methods

We trained and validated a deep neural network using the raw ECG digital data from 425,051 12-lead ECGs acquired between January 2006 and December 2021. The network performed a holdout test using a separate set of 97,058 ECGs. The deep neural network was trained to estimate the AI ECG-heart age [mean absolute error, 5.8 ± 3.9 years; R-squared, 0.7 (r = 0.84, p < 0.05)].

Findings

In the Cox proportional hazards models, after adjusting for relevant comorbidity factors, the patients with an AI ECG-heart age of 6 years older than the CA had higher all-cause mortality (hazard ratio (HR) 1.60 [1.42-1.79]) and more major adverse cardiovascular events (MACEs) [HR: 1.91 (1.66-2.21)], whereas those under 6 years had an inverse relationship (HR: 0.82 [0.75-0.91] for all-cause mortality; HR: 0.78 [0.68-0.89] for MACEs). Additionally, the analysis of ECG features showed notable alterations in the PR interval, QRS duration, QT interval and corrected QT Interval (QTc) as the AI ECG-heart age increased.

Conclusion

Biological heart age estimated by AI had a significant impact on mortality and MACEs, suggesting that the AI ECG-heart age facilitates primary prevention and health care for cardiovascular outcomes.

Acaricidal Activities of Dioscorea japonica Thunb. (Dioscoreales: Dioscoreaceae) Extract and its Constituents Against the Two-spotted Spider Mite, Tetranychus urticae Koch (Trombidiformes: Tetranychidae)

The acaricidal activities of 86 plant extracts were investigated under laboratory conditions. The ethanol extract of Dioscorea japonica Thunb. root showed the strongest acaricidal activity, with 89.3% mortality against two-spotted spider mite, Tetranychus urticae Koch adults at a 2 mg/ml concentration. Bioassay-guided isolation of D. japonica root extract using silica gel open column chromatography, gas chromatography (GC), and gas chromatography-mass spectrometry (GC-MS) identified palmitic acid as the primary active compound. The acaricidal activities of palmitic acid against T. urticae were 91.2% and 69.7% at concentrations of 1 and 0.5 mg/ml, respectively. Among nine saturated fatty acids with carbon chains ranging from C8 to C26, the most vigorous acaricidal activity was observed with octanoic acid, followed by palmitic acid, and decanoic acid at a 1 mg/ml concentration. The acaricidal activity of the other fatty acids was less than 40% mortality at a 1 mg/ml concentration. These results indicate that a suitable carbon length is essential for fatty acids to exhibit acaricidal activity. The acaricidal efficacy of Eungjinssag (EJSG), an organic agricultural material authorized for the management of mites in the Republic of Korea, was compared to D. japonica root extract. At concentrations above 1 mg/ml, the acaricidal activity of D. japonica root extract was stronger than that of EJSG. The results of this study show that D. japonica root extract and palmitic acid are promising candidates as new environmentally-friendly control agents against two-spotted spider mite, which is one of the most severely damaging agricultural arthropod pests.

Factors affecting the prognosis of recovery of motor power and ambulatory function after surgery for metastatic epidural spinal cord compression

OBJECTIVE

Metastatic epidural spinal cord compression (MESCC) causes neurological deficits that may hinder ambulation. Understanding the prognostic factors associated with increased neurological recovery and regaining ambulatory functions is important for surgical planning in MESCC patients with neurological deficits. The present study was conducted to elucidate prognostic factors of neurological recovery in MESCC patients.

METHODS

A total of 192 patients who had surgery for MESCC due to preoperative neurological deficits were reviewed. A motor recovery rate ≥ 50% and ambulatory function restoration were defined as the primary favorable endpoints. Factors associated with a motor recovery rate ≥ 50%, regaining ambulatory function, and patient survival were analyzed.

RESULTS

About one-half (48.4%) of the patients had a motor recovery rate ≥ 50%, and 24.4% of patients who were not able to walk due to MESCC before the surgery were able to walk after the operation. The factors "involvement of the thoracic spine" (p = 0.015) and "delayed operation" (p = 0.041) were associated with poor neurological recovery. Low preoperative muscle function grade was associated with a low likelihood of regaining ambulatory functions (p = 0.002). Furthermore, performing the operation ≥ 72 hours after the onset of the neurological deficit significantly decreased the likelihood of regaining ambulatory functions (p = 0.020). Postoperative ambulatory function significantly improved patient survival (p = 0.048).

CONCLUSIONS

Delayed operation and the involvement of the thoracic spine were poor prognostic factors for neurological recovery after MESCC surgery. Furthermore, a more severe preoperative neurological deficit was associated with a lesser likelihood of regaining ambulatory functions postoperatively. Earlier detection of motor weaknesses and expeditious surgical interventions are necessary, not only to improve patient functional status and quality of life but also to enhance survival.

RF17 | P715 Contribution of Low Muscle Mass and Genetic Factors in NAFLD and Liver Cirrhosis

Introduction

Both sarcopenia and genetic risk factors are important risk factors for non-alcoholic fatty liver disease (NAFLD). We aimed to investigate the independent effects of low muscle mass and genetic risk factors in the development of NAFLD and liver cirrhosis (LC) in the Korean population.

Method: A prospective community-based cohort consisted of adults with age 40–70 years were followed-up biennially from 2001–2002 to 2017–2018. NAFLD was defined as hepatic steatosis index of ≥36, and liver cirrhosis (LC) was defined as a fibrosis-4 index score of ≥1.3. The subjects were divided into four groups according to body mass index (BMI)-adjusted muscle mass. Cox proportional hazards models incorporating age, sex, BMI≥ 25 kg/m², metabolic syndrome, and PNPLA3, and TM6SF2 risk alleles were used to assess the independent determinants for the incident NAFLD and development of LC among individuals with NAFLD at baseline.

Results

Among the 4,038 participants without NAFLD at baseline, 920 (22.8%) developed NAFLD during the follow-up. Both the TM6SF2 risk alleles (hazard ratio [HR]. 1.19, [95% confidence interval (CI), 1.00–1.40], P=0.044) and muscle mass index quartiles (Q) (HR per 1 Q, 1.18, 95% CI, 1.11–1.27, P<0.001) were associated with development of NAFLD in the fully adjusted model.

Of the 1,442 patients with NAFLD at baseline, LC was eventually confirmed in 552 (38.3%) patients. Only the PNPLA3 risk variant, but not the TM6SF2 genotype nor muscle mass index, was an independent risk factor for developing LC among NAFLD subjects (HR 1.22, 95% CI 1.08–1.38, P=0.001)

Conclusion

Both the lower muscle mass index and genetic risk variants are important contributors in the development of NAFLD. In patients already diagnosed with NALFD however, PNPLA3 conferred a greater risk for the progression to LC than lower muscle mass.

Presentation: No date and time listed

Serially Checked Spherical Aberration Can Evaluate the Anti-Myopia Effect of Orthokeratology Lens in Children

We aimed to investigate the changes in higher-order aberrations (HOAs) after wearing orthokeratology (OK) lenses in myopic patients. The study included 15 eyes from ten myopic patients, whose refractive error was myopia less than -4.5 diopters (D) and astigmatism less than 1.5 D. Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) were measured, and Zywave^® aberrometry was performed at baseline and 1, 3, and 6 months following OK lens wear. The mean age was 11.5 years (range: 9-15 years). There was a significant improvement in UCVA (p ≤ 0.001) and a decrease in the spherical equivalent measured with auto-refraction at 6 months (p ≤ 0.001). Total HOAs significantly increased after OK lens wear (p ≤ 0.001), with spherical aberration increasing approximately 3.9-fold (p = 0.05). Spherical aberration demonstrated statistically significant positive correlations with the change in spherical equivalent at 3 and 6 months (p = 0.007 and 0.003, respectively). After wearing properly prescribed OK lens, all subjects had significantly improved UCVA and decreased myopic spherical equivalent, with increased total HOAs and positive spherical aberration at 1 month, and the changes were maintained at 6 months. Serially checked spherical aberration could evaluate the anti-myopia effect of the orthokeratology lens in children.

Optimization of the clinically approved mg-Zn alloy system through the addition of ca

Background

Although several studies on the Mg-Zn-Ca system have focused on alloy compositions that are restricted to solid solutions, the influence of the solid solution component of Ca on Mg-Zn alloys is unknown. Therefore, to broaden its utility in orthopedic applications, studies on the influence of the addition of Ca on the microstructural, mechanical, and corrosion properties of Mg-Zn alloys should be conducted. In this study, an in-depth investigation of the effect of Ca on the mechanical and bio-corrosion characteristics of the Mg-Zn alloy was performed for the optimization of a clinically approved Mg alloy system comprising Ca and Zn.

Methods

The Mg alloy was fabricated by gravitational melting of high purity Mg, Ca, and Zn metal grains under an Ar gas environment. The surface and cross-section were observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to analyze their crystallographic structures. Electrochemical and immersion tests in Hank’s balanced salt solution were used to analyze their corrosion resistance. Tensile testing was performed with universal testing equipment to investigate the impact of Ca addition. The examination of cytotoxicity for biometric determination was in line with the ISO10993 standard.

Results

In this study, the 0.1% Ca alloy had significantly retarded grain growth due to the formation of the tiny and well-dispersed Ca₂Mg₆Zn₃ phase. In addition, the yield strength and elongation of the 0.1% Ca alloy were more than 50% greater than the 2% Zn alloy. The limited cell viability of the 0.3% Ca alloy could be attributed to its high corrosion rate, whereas the 0.1% Ca alloy demonstrated cell viability of greater than 80% during the entire experimental period.

Conclusion

The effect of the addition of Ca on the microstructure, mechanical, and corrosion characteristics of Mg-Zn alloys was analyzed in this work. The findings imply that the Mg-Zn alloy system could be optimized by adding a small amount of Ca, improving mechanical properties while maintaining corrosion rate, thus opening the door to a wide range of applications in orthopedic surgery.

Wavelength-tunable spiral-phase-contrast imaging

Wavelength-tunable spiral-phase-contrast (SPC) imaging was experimentally accomplished in the visible wavelengths spanning a broad bandwidth of ∼200 nm based on a single off-axis spiral phase mirror (OSPM). By the rotation of an OSPM, which was designed with an integer orbital angular momentum (OAM) of l = 1 at a wavelength of 561 nm and incidence angle of 45°, high-quality SPC imaging was obtained at different wavelengths. For the comparison with wavelength-tunable SPC imaging using an OSPM, SPC imaging using a spiral phase plate (manufactured to generate an OAM of l = 1 at 561 nm) was performed at three wavelengths (473, 561, and 660 nm), resulting in clear differences. Theoretically, based on field tracing simulations, high-quality wavelength-tunable SPC imaging could be demonstrated in a very broad bandwidth of ∼400 nm, which is beyond the bandwidth of ∼200 nm obtained experimentally. This technique contribute to developing high-performance wavelength-tunable SPC imaging by simply integrating an OSPM into the current optical imaging technologies.

Significance of Vertebral Body Sliding Osteotomy as a Surgical Strategy for the Treatment of Cervical Ossification of the Posterior Longitudinal Ligament

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Vertebral body sliding osteotomy (VBSO) has previously been reported as a technique to decompress ossification of the posterior longitudinal ligament (OPLL) by translating the vertebral body anteriorly. This study aimed to evaluate the radiological and clinical efficacies of VBSO and clarify the surgical indications of VBSO for treating myelopathy caused by OPLL.

METHODS

Ninety-seven patients with symptomatic OPLL-induced cervical myelopathy treated with VBSO or laminoplasty who were followed up for more than 2 years were retrospectively reviewed. Cervical alignment, range of motion, fusion, modified K-line (mK-line) status, and minimum interval between ossified mass and mK-line (INT_(min)), and the Japanese Orthopaedic Association (JOA) score were assessed. Patients in the VBSO group were compared with those who underwent laminoplasty.

RESULTS

Cervical lordosis and INT_(min) significantly increased in the VBSO group. All patients in the VBSO group assessed as mK-line (-) preoperatively were assessed as mK-line (+) postoperatively. However, in the LMP group, the mK-line status changed from (+) preoperatively to (-) postoperatively in 3 patients. Final JOA score (p = 0.02) and JOA score improvement (p = 0.01) were significantly higher in the VBSO group. JOA recovery ratio (p = 0.03) and proportion of patients with a recovery rate ≥50% were significantly higher in the VBSO group (p < 0.01).

CONCLUSIONS

VBSO is an effective surgical option for OPLL-induced myelopathy, demonstrating favorable neurological recovery and lordosis restoration with low complication rates. It is best indicated for kyphotic alignment, OPLL with a high space-occupying ratio, and OPLL involving ≤3 segments.