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Transcatheter aortic valve replacement (TAVR) is the standard of care for severe, symptomatic aortic stenosis. Real-world TAVR data collection contributes to benefit/risk assessment and safety evidence for the U.S. Food and Drug Administration, quality evaluation for the Centers for Medicare and Medicaid Services and hospitals, as well as clinical research and real-world implementation through appropriate use criteria. The essential minimum core dataset for these purposes has not previously been defined but is necessary to promote efficient, reusable real-world data collection supporting quality, regulatory, and clinical applications. The authors performed a systematic review of the published research for high-impact TAVR studies and U.S. multicenter, multidevice registries. Two expert task forces, one from the Predictable and Sustainable Implementation of National Cardiovascular Registries/Heart Valve Collaboratory and another from The Society of Thoracic Surgeons/American College of Cardiology TVT (Transcatheter Valve Therapy) Registry convened separately and then met to reconcile a final list of essential data elements. From 276 unique data elements considered, unanimous consensus agreement was achieved on 132 "core" data elements, with the most common reasons for exclusion from the minimum core dataset being burden or difficulty in accurate assessment (36.9%), duplicative information (33.3%), and low likelihood of affecting outcomes (10.7%). After a systematic review and extensive discussions, a multilateral group of academicians, industry representatives, and regulators established 132 interoperable, reusable essential core data elements essential to supporting more efficient, consistent, and informative TAVR device evidence for regulatory submissions, safety surveillance, best practice, and hospital quality assessments. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract For years, bioengineers and orthopaedic surgeons have applied the principles of mechanics to gain valuable information about the complex function of the anterior cruciate ligament (ACL). The results of these investigations have provided scientific data for surgeons to improve methods of ACL reconstruction and postoperative rehabilitation. This review paper will present specific examples of how the field of biomechanics has impacted the evolution of ACL research. The anatomy and biomechanics of the ACL as well as the discovery of new tools in ACL-related biomechanical study are first introduced. Some important factors affecting the surgical outcome of ACL reconstruction, including graft selection, tunnel placement, initial graft tension, graft fixation, graft tunnel motion and healing, are then discussed. The scientific basis for the new surgical procedure, i.e., anatomic double bundle ACL reconstruction, designed to regain rotatory stability of the knee, is presented. To conclude, the future role of biomechanics in gaining valuable in-vivo data that can further advance the understanding of the ACL and ACL graft function in order to improve the patient outcome following ACL reconstruction is suggested.

The objective is to investigate the biomechanical conditions of the Posterior Vertebral Column Resection (PVCR) of the constructed scoliosis 3D finite element model. A patient with scoliosis was selected; before the PVCR orthopaedy, the patient was submitted to the radiography of normal and lateral full-length vertebral column scans and the total magnetic resonance imaging (MRI) scans; then, the idiopathic scoliosis model was constructed by the 3D finite element method, and the 3D finite element software utilized in the process of model construction included Mimics software, Geomagic Studio 12 software, and Unigraphic 8.0 (UG 8.0) software; in addition, PVCR orthopaedy was utilized to correct the scoliosis of the patient, and the biomechanical parameters, such as orthodontic force, vertebral body displacement, orthopedic rod stress, stress on the pin-bone interface of the vertebral body surface, and the stress on the intervertebral disc, were studied. The 3D effective finite element model of scoliosis was successfully constructed by the Mimics software, the Geomagic Studio 12 software, and the UG 8.0 software, and the effectiveness was tested. PVCR orthopaedy could effectively solve the problem of scoliosis. The magnitude of the orthodontic force that a patient needed depended on the physical conditions and the personal orthodontic requirements of the patient. The maximum vertebral body displacement on the X-axis was the vertebral body L1, the maximum displacement on the Y-axis was the vertebral body T3, the maximum displacement on the Z-axis was the vertebral body T1, and the rang of orthopedic rod stress was 0.0050214e7 MPa to 0.045217e7 MPa, in which the maximum stress of 2 vertebral bodies in, above, and below the osteotomy area reached 0.045217e7 MPa, the stress on the pin-bone interface of the T10 vertebral body surface reached 11.83 MPa, and the stress of T8/T9 intervertebral disc reached 13.84 MPa. The 3D finite element model based on 3D finite element software was highly efficient, and its numerical simulation was accurate, which was important for the subsequent biomechanical analysis of PVCR orthopaedy. In addition, the vertebral stress of PVCR orthopaedy was different in each body part, which was mainly affected by the applied orthodontic force and the sites of the orthodontic area. [ABSTRACT FROM AUTHOR]

Background: Transcatheter aortic valve replacement (TAVR) is a less invasive alternative approach to surgery. Individual randomized clinical trials evaluating the safety and efficacy of TAVR were mostly underpowered for conducting separate analyses for women and men. We pooled data from premarket TAVR clinical trials comparing short (30 days)- and long-term (∼2 years) outcomes by sex. Methods: Patient-level data from the TAVR arms of six clinical trials were pooled (2515 patients). Random-effects models for time-to-event outcomes (odds ratios [ORs] for 30-day outcomes and hazard ratios [HRs] for complete follow-up for mortality, ischemic stroke, kidney injury, major bleeding, myocardial infarction, and device migration) and dichotomous outcomes (ORs for reintervention, rehospitalization, and pacemaker implantation) were then fit to directly compare outcomes between women and men. Results: Overall, the pattern of individual comorbidities was more severe in men. There was no difference in mortality risk at 30 days (female-to-male OR = 1.00 [0.69–1.46]); however, at follow-up completion (∼2 years post-TAVR), women had a 24% lower mortality risk than men (HR = 0.76 [95% CI: 0.65–0.89]). Women also had a 30% lower risk of kidney injury at 30 days (OR = 0.70 [0.49–0.98]), which increased to 33% over the complete follow-up period (HR = 0.67 [0.51–0.87]). Major bleeding was more common in women compared to men at both 30 days (OR = 1.44 [1.19–1.76]) and long-term follow-up (HR = 1.22 [1.04–1.43]). For dichotomous outcomes, women had a 68% lower risk for reinterventions (OR = 0.32 [0.18–0.58]). We did not observe any difference in the risk of ischemic stroke, myocardial infarction, device migration, rehospitalizations, or pacemaker implantations between sexes. Conclusions: This patient-level data meta-analysis of six premarket clinical trials found that women who received TAVR had fewer comorbidities at baseline. Acute outcomes (30 day) with respect to mortality were similar. Women were observed to have a lower risk of kidney injury, but higher risk of major bleeding compared to men receiving TAVR at 30 days. At complete follow-up, statistically significant advantages for women emerged in improved survival and lower reintervention risk. No differences in ischemic stroke, pacemaker implantation, or rehospitalization were observed. That women are healthier at baseline and develop fewer postprocedural complications than men may explain their higher survival. [ABSTRACT FROM AUTHOR]

Background: Accurate placement of pedicle screw during Anterior Transpedicular Screw fixation (ATPS) in cervical spine depends on accurate anatomical knowledge of the vertebrae. However, little is known of the morphometric characteristics of cervical vertebrae in Chinese population. Methods: Three-dimensional reconstructions of CT images were performed for 80 cases. The anatomic data and screw fixation parameters for ATPS fixation were measured using the Mimics software. Findings: The overall mean OPW, OPH and PAL ranged from 5.81 to 7.49 mm, 7.77 to 8.69 mm, and 33.40 to 31.13 mm separately, and SPA was 93.54 to 109.36 degrees from C3 to C6, 104.99 degrees at C7, whereas, 49.00 to 32.26 degrees from C4 to C7, 46.79 degrees at C3 (TPA). Dl/rSIP had an increasing trend away from upper endplate with mean value from 1.87 to 5.83 mm. Dl/rTIP was located at the lateral portion of the anterior cortex of vertebrae for C3 to C5 and ipsilateral for C6 to C7 with mean value from −2.70 to −3.00 mm, and 0.17 to 3.18 mm. The entrance points for pedicular screw insertion for C3 to C5 and C6 to C7 were recommended −2∼−3 mm and 0–4 mm from the median sagittal plane, respectively, 1–4 mm and 5–6 mm from the upper endplate, with TPA being 46.79–49.00 degrees and 40.89–32.26 degrees, respectively, and SPA being 93.54–106.69 degrees and 109.36–104.99 degrees, respectively. The pedicle screw insertion diameter was recommended 3.5 mm (C3 and C4), 4.0 mm (C5 to C7), and the pedicle axial length was 21–24 mm for C3 to C7 for both genders. However, the ATPS insertion in C3 should be individualized given its relatively small anatomical dimensions. Conclusions: The data provided a morphometric basis for the ATPS fixation technique in lower cervical fixation. It will help in preoperative planning and execution of this surgery. [ABSTRACT FROM AUTHOR]

Abstract: The serine/threonine kinase Pim-1 was recently identified as a cardiomyocyte survival regulator downstream of Akt. The present study aims to examine Pim-1 activity and its association with the post MI remodeling myocardium in a clinically relevant large animal model. Apical myocardial infarction of approximately 25% left ventricular mass was created in an ovine model. Regional post-infarction deformation of the left ventricle was monitored by sonomicrometry and quantified using areal remodeling strain (i.e., areal expansion). Myocardial tissues were harvested at 12weeks from the adjacent and remote regions of the infarct for analysis of Pim-1 mediated survival signaling proteins as well as apoptotic activity. The cDNA coding sequences of two ovine Pim-1 kinase isoforms, 44 and 33kDa, were identified. Both isoforms were detected in heart tissue and the overall Pim-1 expression was found to be tightly controlled at multiple molecular levels. Pim-1 as well as the Pim-1 mediated survival signaling proteins Bcl-2, Bcl-xL, and phospho-Bad (Ser112) were upregulated in the adjacent region at 12weeks post-infarction and their expression correlated positively with the degree of the remodeling, which was accompanied by significant upregulations of the PP2A/BAD mediated apoptotic signaling proteins. However these upregulations were imbalanced, such that p-BAD (Ser112)/BAD decreased in the adjacent region of the infarcted hearts. Apoptotic activity also increased with remodeling strain. Despite an observed intrinsic upregulation of survival proteins, the imbalanced activation of apoptotic pathways resulted in evident apoptosis in the adjacent region. Ultramini-abstract: Pim-1 mediated survival signaling in myocardial tissues from infarcted ovine hearts was studied. It was shown that the adjacent region of the infarct experienced higher remodeling strain and exhibited increased levels of Pim-1 and related anti-apoptotic proteins. Despite this elevation of survival activity, however, the imbalanced activation of PP2A/BAD mediated apoptotic pathway resulted in evident apoptosis in the adjacent region. [Copyright &y& Elsevier]

Objective: To investigate the feasibility of the use of 3D-printed guiding templates for accurate placement of plates and screws for internal fixation of acetabular fractures.Methods: 3D models of the pelvises of 14 adult cadavers were reconstructed using computed tomography (CT). Twenty-eight acetabular fractures were simulated and placement positions for plates and screw trajectories were designed. Bending module was obtained by 3D cutting; guiding template was manufactured using 3D printing, and the plate was pre-bent according to the bending module. Plates and screws were placed in cadaveric pelvises using the guiding template, and 3D model was reconstructed using CT. The designed and real trajectories were matched using 3D registration including the coordinates (entry and exit points) of designed trajectory. The number of qualified points with different accuracy levels was compared using Chi-squared test.Results: Sixty-four plates and 339 screws were placed with no cortical breach. The absolute difference of the X, Y, and Z coordinates between the designed and real entry points were 0.52±0.45, 0.43±0.36, and 0.53±0.44mm, respectively. The corresponding values for the exit points were 0.83±0.67, 1.22±0.87, and 1.26±0.83mm, respectively. With an accuracy degree ≥1.9mm for the entry points and ≥3.8mm for the exit points, there was no significant difference between the designed and the real trajectories.Conclusion: The 3D-printed guiding template helped achieve accurate placement of plates and screws in the pelvis of adult cadavers. [ABSTRACT FROM AUTHOR]

Abstract: Background: The underlying molecular mechanisms of the remodeling after myocardial infarction (MI) remain unclear. The purpose of this study was to investigate the role of a survival pathway (PI3K/Akt) and an apoptosis pathway (calcineurin/BAD) in the remodeling after MI in a large animal model. Methods: Ten Dorset hybrid sheep underwent 25% MI in the left ventricle (LV, n=10). Five sheep were used as sham control. The regional strain was calculated from sonomicrometry. Apoptosis and the activation of the PI3K/Akt and calcineurin/BAD pathways were evaluated in the non-ischemic adjacent zone and the remote zone relative to infarct by immunoblotting, immunoprecipitation, and immunofluorescence staining. Results: Dilation and dysfunction of LV were present at 12weeks after MI. The regional strain in the adjacent zone was significantly higher than in the remote zone at 12weeks (36.6±4.0% vs 9.5±3.6%, p< 0.05). Apoptosis was more severe in the adjacent zone than in the remote zone. The PI3K/Akt and calcineurin/BAD pathways were activated in the adjacent zone. Dephosphorylation and translocation of BAD were evident in the adjacent zone. Regional correlation between the strain and the expression of calcineurin/BAD indicated that the activation was strain-related (R 2 =0.46, 0.48, 0.39 for calcineurin, BAD, mitochondrial BAD, respectively, p <0.05). Conclusions: The PI3K/Akt survival and calcineurin/BAD apoptotic pathways were concomitantly activated in the non-ischemic adjacent zone after MI. The calcineurin/BAD pathway is strain related and its imbalanced activation may be one of the causes of progressive remodeling after MI. [Copyright &y& Elsevier]

Importance: Improving patients' health status is a key goal of treating tricuspid regurgitation (TR). The Kansas City Cardiomyopathy Questionnaire (KCCQ) is a heart failure disease-specific health status measure used to capture the health status impact of TR and the benefit of transcatheter tricuspid valve intervention (TTVI), but its validity in this clinical setting is unknown., Objective: To evaluate the psychometric properties of the KCCQ in patients with TR., Design, Setting, and Participants: Data were pooled from patients with severe TR enrolled in 11 manufacturer-sponsored trials of TTVI. The data were transferred to the US Food and Drug Administration to harmonize and anonymize prior to analysis by an independent center. Data were collected from December 2015 to April 2023, and data analysis was performed from July to October 2023., Main Outcomes and Measures: Prespecified analyses included evaluation of internal consistency, reproducibility, responsiveness, construct validity, and predictive validity. Outcomes were determined using Cronbach α, score comparisons, intraclass correlation, Cohen d, Spearman correlations with best available reference measures, and association of scores and changes in scores with risk of subsequent clinical events., Results: The study cohort was composed of 2693 patients enrolled in either single-arm (n = 1517) or randomized (n = 1176) investigations of TTVI. Mean (SD) patient age was 78.6 (8.0) years, 1658 of 2693 patients (61.6%) were female, and the mean (SD) baseline KCCQ Overall Summary (KCCQ-OS) score was 50 (23). There was strong internal consistency within individual domains (Cronbach α, .77-.83). Among clinically stable patients between 1 and 6 months, there were small mean changes in KCCQ domain and summary scores (differences of -0.1 to 1.9 points), demonstrating reproducibility. In contrast, domain and summary scores of patients who underwent TTVI showed large improvements at 1 month after treatment (mean changes, 12.1-21.4 points), indicating excellent perceived responsiveness. Construct validity was moderately strong when domains were compared with best available reference measures (Spearman correlations, 0.47-0.69). In both cross-sectional and longitudinal analyses, the KCCQ-OS was associated with clinical events, with lower scores associated with an increased risk of mortality (hazard ratio, 1.34 per 10-point decrement; 95% CI, 1.22-1.47) and heart failure hospitalization (hazard ratio, 1.24 per 10-point decrement; 95% CI, 1.17-1.31)., Conclusions and Relevance: In this cohort study, the KCCQ had strong psychometric properties in patients with severe TR, including reliability, responsiveness, and validity. These data support use of the KCCQ in patients with severe TR as a measure of their symptoms, function, and quality of life and also for assessing the impact of interventions, such as TTVI, in rigorously controlled trials.

A visible-light-triggered ring opening/in situ SO 2 -capture/alkynylation sequence of cyclopropyl alcohols with alkynyl triflones using 4CzIPN as a triplet energy transfer photocatalyst is herein described. This metal-free protocol provides a straightforward and atom-economical approach to alkynyl-substituted γ-keto sulfones with a broad scope of substituents. In this transformation, alkynyl triflones could be used as both radical acceptors and SO 2 donors. Preliminary experimental mechanistic studies and synthetic utility are also demonstrated.

Background: The labeled sizes of surgical valve prostheses and their discordance with the physical internal valve orifice sizes has long been a controversy in the cardiac surgery community, leading many to believe it to be a contributing factor in prosthesis-patient mismatch following valvular replacement surgery. In an attempt to address this issue, the International Organization for Standardization (ISO) 5840-2:2021 standard for surgical valve prostheses recommends that a new sizing parameter, namely, the effective orifice diameter, be provided in labeling by all manufacturers as an indicator of the true flow-passing capacity of a prosthetic valve., Methods: The ISO Cardiac Valves Working Group conducted a multi-laboratory round-robin study to investigate whether the effective orifice diameter of a prosthetic surgical valve could be derived repeatably and reproducibly through steady forward-flow testing. A total of seven valve models, each with multiple sizes, were tested, including a mechanical heart valve and multiple biological heart valves., Results: The round-robin study confirmed that the steady forward-flow test had good intra-laboratory repeatability and inter-laboratory reproducibility in deriving the effective orifice diameters of surgical valve prostheses. On average, among the participating laboratories, the experimentally derived effective orifice diameter of a prosthetic heart valve was 3-12 mm smaller than its labeled size., Conclusions: The effective orifice diameter provides better characterization of the hydrodynamic characteristics of a surgical valve prosthesis and can be derived using a validated steady forward-flow test method. This new sizing parameter will soon be adopted by surgical valve manufacturers and provided in device labeling to inform valve selection by surgeons., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare., (2024 Annals of Cardiothoracic Surgery. All rights reserved.)

Objective: This study aimed to investigate the prevalence of glaucoma with associated factors in the rural populations of 10 provinces in China., Design: A population-based cross-sectional study., Methods: All participants aged 6 years or older from 10 provinces completed visual acuity testing, slit-lamp examination, ophthalmoscopy and non-contact tonometry. Glaucoma suspects underwent fundus photography, Goldmann applanation tonometry, visual field testing and gonioscopy. Glaucoma was determined according to the International Society of Geographical and Epidemiological Ophthalmology classification scheme. Associations of demographics and medical factors with glaucoma were assessed using multiple logistic regression models., Results: From June 2017 to October 2018, 48 398 of 52 041 participants were included in the final analyses. The age-standardised prevalence of glaucoma was 1.7% (95% CI 1.55% to 1.78%) among the participants older than 6 years, which was 2.1% (95% CI 1.93% to 2.23%) in participants aged over 40 years. The constituent ratios of glaucoma were: 44.4% primary angle-closure glaucoma (PACG), 34.7% primary open-angle glaucoma, 2.6% congenital glaucoma and 18.3% other types of glaucoma. Increasing age, smoking, cerebral stroke, type 2 diabetes, higher education (college or more) and higher personal income were significant risk factors for PACG. The unilateral and bilateral blindness rates in the entire study population were 4.692% and 1.068%, respectively. A family history of glaucoma was a significant risk factor for the prevalence of glaucoma and blindness in at least one eye., Conclusions: Rural populations have a high prevalence of glaucoma, which should be included in chronic disease management programmes in China for long-term care., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: There is still controversy about the effect of vitamin D supplementation on osteoarthritis (OA). The purpose of this study was to investigate the effects of vitamin D supplementation with Hyaluronic acid (HA) injection on OA., Methods: We investigated serum vitamin D levels and oxidative stress (OS) in synovial fluid from patients with OA who underwent total knee arthroplasty (grade IV, n = 24) and HA injection (grade II and III, n = 40). The effects of HA injection with or without oral vitamin D supplementation on synovial fluid OS and knee pain and function were then further investigated. Finally, patients underwent HA injection were divided into two groups according to vitamin D levels (vitamin D < or > 30 ng/ml), and the efficacy of the two groups were compared., Results: The results showed that the levels of glutathione peroxidase (GSH-PX) ( P < 0.05) in the synovial fluid were lower in patients with stage IV OA than that in patients with stage II-III OA, while the levels of malondialdehyde (MDA) ( P < 0.05) and lactate dehydrogenase (LDH) ( P < 0.01) were significantly higher. Moreover, we found that age, BMI and vitamin D levels were significantly associated with the levels of oxidants and/or antioxidants in synovial fluid, and that vitamin D was significantly negatively correlated with BMI ( R = -0.3527, p = 0.0043). Supplementation of HA injections with vitamin D significantly reduced the OS status in synovial fluid, attenuated knee pain and improved knee function in OA patients with vitamin D insufficiency., Conclusion: We conclude that maintenance of vitamin D sufficiency may be beneficial for the treatment of OA by improving OS in synovial fluid., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Shen, Lin, Lin, Xiao, Wu, Zheng, Wu, Lin, Chen and Liu.)

Transcatheter aortic valves (TAV) are symmetrically designed, but they are often not deployed inside cylindrical conduits with circular cross-sectional areas. Many TAV patients have heavily calcified aortic valves, which often result in deformed prosthesis geometries after deployment. We investigated the effects of deformed valve annulus configurations on a surgical bioprosthetic valve as a model for TAV. We studied valve leaflet motions, stresses and strains, and analog hydrodynamic measures (using geometric methods), via finite element (FE) modeling. Two categories of annular deformations were created to approximate clinical observations: (1) noncircular annulus with valve area conserved, and (2) under-expansion (reduced area) compared to circular annulus. We found that under-expansion had more impact on increasing stenosis (with geometric orifice area metrics) than noncircularity, and that noncircularity had more impact on increasing regurgitation (with regurgitation orifice area metrics) than under-expansion. We found durability predictors (stress/strain) to be the highest in the commissure regions of noncircular configurations such as EllipMajor (noncircular and under-expansion areas). Other clinically relevant performance aspects such as leaflet kinematics and coaptation were also investigated with the noncircular configurations. This study provides a framework for choosing the most challenging TAV deformations for acute and long-term valve performance in the design and testing phase of device development., (Copyright © 2020 by ASME.)

Background: The Transcatheter Valve Therapy (TVT) Coordinated Registry Network (CRN) supported 23 regulatory decisions and ensured evidence-based evaluation of the application of TVT technology. However, there are cost concerns that require value assessment of the TVT CRN compared with traditional study designs., Objectives: We aimed to determine the value created by the TVT CRN based on (1) Return on investment (ROI), (2) Time saved (TS) in conducting necessary regulatory studies., Methods: For both ROI and TS analyses, we compared studies that used the TVT CRN with those that would have been required if the registry did not exist (counterfactual studies). To estimate ROI, we accounted for the costs of investment and gain from investment. Both the counterfactual costs and length of studies were projected using design specifications determined by US Food and Drug Administration (FDA) reviewers., Results: We identified 21 studies using the TVT CRN (supporting 23 FDA decisions) that generated evidence on TVT for three device manufacturers. ROI is estimated to be greater than 550%. TS by using the CRN ranged from months to years., Conclusions: The CRN method to evidence generation creates value for manufacturers and the broader device ecosystem, demonstrated with this example of the TVT CRN. The public health benefits of evidence created by this CRN outweighs the difference in data quality between traditional clinical studies and the CRN method., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

A finite element model was used to compare the biomechanical properties of a novel anterior transpedicular screw artificial vertebral body system (AVBS) with a conventional anterior screw plate system (ASPS) for fixation in the lower cervical spine. A model of the intact cervical spine (C3-C7) was established. AVBS or ASPS constructs were implanted between C4 and C6. The models were loaded in three-dimensional (3D) motion. The Von Mises stress distribution in the internal fixators was evaluated, as well as the range of motion (ROM) and facet joint force. The models were generated and analyzed by mimics, geomagic studio, and ansys software. The intact model of the lower cervical spine consisted of 286,382 elements. The model was validated against previously reported cadaveric experimental data. In the ASPS model, stress was concentrated at the connection between the screw and plate and the connection between the titanium mesh and adjacent vertebral body. In the AVBS model, stress was evenly distributed. Compared to the intact cervical spine model, the ROM of the whole specimen after fixation with both constructs is decreased by approximately 3 deg. ROM of adjacent segments is increased by approximately 5 deg. Facet joint force of the ASPS and AVBS models was higher than those of the intact cervical spine model, especially in extension and lateral bending. AVBS fixation represents a novel reconstruction approach for the lower cervical spine. AVBS provides better stability and lower risk for internal fixator failure compared with traditional ASPS fixation.

Objective: To explore the feasibility and the effectiveness of the accurate placement of lumbar pedicle screws using three-dimensional (3D) printing navigational templates in Quadrant minimally invasive system., Methods: The L 1-5 spines of 12 adult cadavers were scanned using CT. The 3D models of the lumbar spines were established. The screw trajectory was designed to pass through the central axis of the pedicle by using Mimics software. The navigational template was designed and 3D-printed according to the bony surface where the soft tissues could be removed. The placed screws were scanned using CT to create the 3D model again after operation. The 3D models of the designed trajectory and the placed screws were registered to evaluate the placed screws coincidence rate. Between November 2014 and November 2015, 31 patients with lumbar instability accepted surgery assisted with 3D-printing navigation module under Quadrant minimally invasive system. There were 14 males and 17 females, aged from 42 to 60 years, with an average of 45.2 years. The disease duration was 6-13 months (mean, 8.8 months). Single segment was involved in 15 cases, two segments in 13 cases, and three segments in 3 cases. Preoperative visual analogue scale (VAS) was 7.59±1.04; Oswestry disability index (ODI) was 76.21±5.82; and the Japanese Orthopaedic Association (JOA) score was 9.21±1.64., Results: A total of 120 screws were placed in 12 cadavers specimens. The coincidence rate of placed screw was 100%. A total of 162 screws were implanted in 31 patients. The operation time was 65-147 minutes (mean, 102.23 minutes); the intraoperative blood loss was 50-116 mL (mean, 78.20 mL); and the intraoperative radiation exposure time was 8-54 seconds (mean, 42 seconds). At 3-7 days after operation, CT showed that the coincidence rate of the placed screws was 98.15% (159/162). At 4 weeks after operation, VAS, ODI, and JOA score were 2.24±0.80, 29.17±2.50, and 23.43±1.14 respectively, showing significant differences when compared with preoperative ones ( t =14.842, P =0.006; t =36.927, P =0.002; t =-36.031, P =0.001). Thirty-one patients were followed up 8-24 months (mean, 18.7 months). All incision healed by first intention, and no complication occurred. During the follow-up, X-ray film and CT showed that pedicle screw was accurately placed without loosening or breakage, and with good fusion of intervertebral bone graft., Conclusion: 3D-printing navigational templates in Quadrant minimally invasive system can help lumbar surgery gain minimal invasion, less radiation, and accurate placement.