Using preoperative planning software to assess the effect of head length on prosthetic range of motion in a high-risk population: a three-dimensional modeling study.

PURPOSE: Concurrent use of minus heads with tapered stems in total hip arthroplasty (THA) decreases the prosthetic range of motion (pROM). Three-dimensional preoperative templating can simulate the location of the impingement by taking the hip through a virtual pROM. This enables surgeons to simulate how modifying the type of implant, orientation, and position influences impingement. We hypothesized that CT-based modeling would result in a decrease in the pROM, thereby increasing the risk of impingement when minus heads are used. METHODS: Forty-three patients who underwent robotic-assisted primary THAs were included. Prosthetic head diameter (32/36-mm) and head length (minus/zero/plus) were the predictors. Maximum external rotation at full hip extension and internal rotation at 90° and 100° of flexion prior to prosthetic impingement were the outcome variables. A CT-based preoperative planning software was used for pROM estimation and impingement detection. RESULTS: Significant decreases in pROM were found for both head diameters as the head length decreased and was more pronounced in external rotation during full hip extension (changes of 2.8-3.4° for the 32-mm head and 1.6-2.8° for the 36-mm head (p = 0.00011)). The magnitude of loss in pROM when using a minus head was larger than the gain provided by a plus head in tapered stems (p < 0.0001). CONCLUSION: Head length affects the offset and pROM. When the use of minus heads or smaller heads is indicated, 3D preoperative templating for assessing postoperative pROM and impingement provides surgeons with options to consider alternate surgical plans offering additional assurance and protection from dislocation.

Unnatural Peptide Assemblies Rapidly Deplete Cholesterol and Potently Inhibit Cancer Cells.

Cholesterol-rich membranes play a pivotal role in cancer initiation and progression, necessitating innovative approaches to target these membranes for cancer inhibition. Here we report the first case of unnatural peptide (1) assemblies capable of depleting cholesterol and inhibiting cancer cells. Peptide 1 self-assembles into micelles and is rapidly taken up by cancer cells, especially when combined with an acute cholesterol-depleting agent (MßCD). Click chemistry has confirmed that 1 depletes cell membrane cholesterol. It localizes in membrane-rich organelles, including the endoplasmic reticulum, Golgi apparatus, and lysosomes. Furthermore, 1 potently inhibits malignant cancer cells, working synergistically with cholesterol-lowering agents. Control experiments have confirmed that C-terminal capping and unnatural amino acid residues (i.e., BiP) are essential for both cholesterol depletion and potent cancer cell inhibition. This work highlights unnatural peptide assemblies as a promising platform for targeting the cell membrane in controlling cell fates.

The impact of base design and restoration type on the resin consumption, trueness, and dimensional stability of dental casts additively manufactured from liquid crystal display 3D printers.

PURPOSE: To evaluate the effects of two base types and three restoration designs on the resin consumption and trueness of the 3D-printed dental casts. Additionally, the study explored the dimensional stability of these 3D-printed dental casts after 1 year of storage. MATERIALS AND METHODS: Various types of reference dental casts were specifically designed to represent three types of dental restoration fabrications, including full-arch (FA), long-span (LS), and single-unit (SU) prostheses. The reference casts were digitized with a dental laboratory scanner and used to create flat and hollow base designs (N = 18) for the 3D-printed study casts. The 3D-printed study casts were digitized and evaluated against their corresponding references immediately after 3D printing and again after 1 year of storage, with the trueness quantified using the root mean square error (RMSE) at both time points. Volumes of resin used were recorded to measure resin consumption, and the weights of the 3D-printed study casts were also measured. The data were analyzed using two-way ANOVA and a Tukey post hoc test, α = 0.05. RESULTS: Volumetric analysis showed the flat-base design had significantly higher resin consumption with weights for the FA group at 42.51 ± 0.16 g, the LS group at 31.64 ± 0.07 g, and the SU group at 27.67 ± 0.31 g, as opposed to 26.22 ± 1.01 g, 22.86 ± 0.93 g, and 20.10 ± 0.19 g for the hollow designs respectively (p < 0.001). Trueness, assessed through two-way ANOVA, revealed that the flat-base design had lower RMSE values indicating better trueness in the LS (54 ± 6 µm) and SU (59 ± 7 µm) groups compared to the hollow-base design (LS: 73 ± 5, SU: 99 ± 11 µm, both p < 0.001), with no significant difference in the FA group (flat-base: 50 ± 3, hollow: 47 ± 5 µm, p = 0.398). After 1 year, the flat-base design demonstrated superior dimensional stability in the LS (flat base: 56 ± 6 µm, hollow base: 149 ±45 µm, p < 0.001) and SU groups (flat base: 95 ± 8 µm, hollow base: 183 ±27 µm, p < 0.001), with the FA group showing no significant difference in the base design (flat base: 47 ± 9, hollow base: 62 ± 12 µm, p = 0.428). CONCLUSIONS: The hollow-base design group showed lower resin consumption than the flat-base design group. However, the flat-base designs exhibited superior trueness and less distortion after 1 year of storage. These findings indicate that despite the higher material usage, flat-base designs provide better initial accuracy and maintain their dimensional stability over time for most groups.

Color stability of CAD-CAM hybrid ceramic materials following immersion in artificial saliva and wine.

PURPOSE: To examine the color stability of 3D-printed and milled, interim, and definitive, restorative materials after immersion in artificial saliva and wine for 1, 3, and 6 months. MATERIAL AND METHODS: The study used a 2 × 5 factorial design with 10 subgroups, including 2 immersion liquids (artificial saliva and wine) and 5 manufacturing technology and restorative material combinations (n = 10). Color measurements were taken using a contact-type digital spectrophotometer (CM-2600d Spectrophotometer; Konica Minolta Healthcare Americas Inc) before immersion and at 1 month (T1), 3 months (T3), and 6 months (T6) after immersion. The CIE2000 system was used to calculate quantitative measurements of color differences in ΔE00, and comparisons were made to the acceptability threshold (AT) and perceptibility threshold (PT). Repeated measures of ANOVA (α = 0.05) were used to compare differences in color changes between manufacturing technology/restorative material-immersion liquid combinations at T1, T3, and T6. RESULTS: To compare the effect of immersion liquid and time on the manufacturing technology/restorative material groups, the ΔE00 values were compared to the PT of 0.8 and the AT of 1.8. Wine caused significant color changes in ΔE00 values beyond the PT and AT values in all groups at all time intervals, except for the AT value of milled definitive crowns (hybrid nano-ceramic material). Wine immersion caused significant ΔE00 for all manufacturing technology/restorative material groups at all time intervals (1 month, 3 months, and 6 months) when compared to artificial saliva immersion (all p < 0.001). CONCLUSION: Upon exposure to artificial saliva, 80%-100% of samples from all groups remained within the acceptable and perceptible color change thresholds. The wine had significant chromogenic effects on all tested restorative materials, however, the milled definitive crowns (hybrid nano-ceramic material) showed the greatest color stability. For patients with heavy wine consumption, 3D-printed definitive crowns (hybrid ceramic-filled material) may show discoloration exceeding acceptable and perceptible color change limits.

Long-term surgical outcomes of bile duct tumor thrombus versus portal vein tumor thrombus for hepatocellular carcinoma: a propensity score matching analysis.

Background: Portal vein tumor thrombus (PVTT) seriously affects the prognosis of hepatocellular carcinoma (HCC). However, whether bile duct tumor thrombus (BDTT) significantly affects the prognosis of HCC as much as PVTT remains unclear. We aimed to compare the long-term surgical outcomes of HCC with macroscopic PVTT (macro-PVTT) and macroscopic BDTT (macro-BDTT). Methods: The data of HCC patients with macro-BDTT or macro-PVTT who underwent hemihepatectomy were retrospectively reviewed. A propensity score matching (PSM) analysis was performed to reduce the baseline imbalance. The recurrence-free survival (RFS) and overall survival (OS) rates were compared between the cohorts. Results: Before PSM, the PVTT group had worse RFS and OS rates than the BDTT group (P = 0.043 and P = 0.008, respectively). Multivariate analyses identified PVTT (hazard ratio [HR] = 1.835, P = 0.016) and large HCC (HR = 1.553, P = 0.039) as independent risk factors for poor OS and RFS, respectively. After PSM, the PVTT group had worse RFS and OS rates than the BDTT group (P = 0.037 and P = 0.004, respectively). The 3- and 5-year OS rates were significantly higher in the BDTT group (59.5% and 52.1%, respectively) than in the PVTT group (33.3% and 20.2%, respectively). Conclusion: Aggressive hemihepatectomy provides an acceptable prognosis for HCC patients with macro-BDTT. Furthermore, the long-term surgical outcomes of HCC patients with macro-BDTT were significantly better than those of HCC patients with macro-PVTT.

The 3D-printed shell complete denture technique: Simplifying prosthodontic diagnosis prior to implant planning.

Traditionally, artificial teeth arrangements or the definitive complete dentures are used to establish important prosthodontic parameters such as the occlusal plane orientation, vertical dimension, and the incisal edge position. The relationship of these elements with the underlying bony structures is commonly evaluated using advanced planning protocols such as the dual scan technique. This technique article presents an uncomplicated alternative approach to establish these parameters intraorally using a 3D-printed shell complete denture generated from a 3D scan of the patient's existing complete denture.

Clinical outcomes of milled, 3D-printed, and conventional complete dentures in edentulous patients: A systematic review and meta-analysis.

PURPOSE: This systematic review aims to compare clinical outcomes of digital dentures with conventional dentures. MATERIALS AND METHODS: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in Prospero. The formulated population, intervention, comparison, outcome (PICO) question was "What is the clinical outcome of digital versus conventional complete dentures (CDs) in edentulous patients?". The search strategy used three main electronic databases and an additional manual search was completed in August 2023 by following an established search strategy. Initial inclusion was based on titles and abstracts, followed by a detailed review of selected studies, and clinical studies that evaluated the clinical outcome of digital (milled or 3D-printed) versus conventional CDs were included. A qualitative analysis for clinical studies was used to assess the risk of bias. The certainty of the evidence was assessed according to the grading of recommendations, assessment, development, and evaluations (GRADE) system. In addition, a single-arm meta-analysis was performed to evaluate the retention between digital versus conventional CDs. RESULTS: The initial search yielded a total of 947 articles, out of which 19 were selected for a comprehensive review, and six met the eligibility criteria to be included in this systematic review. The computer-aided design and computer-aided manufacturing (CAD-CAM) CDs showed increased retention, no relevant differences in oral health-related quality of life (OHRQoL), and shorter working time compared to conventional dentures. Two studies were eligible for meta-analysis; retention was significantly better among CAD-CAM fabricated dentures (standardized mean difference [SMD] 0.501) than conventional dentures. The heterogeneity between studies was high (95% CI: 0.049-0.952). CONCLUSIONS: Clinically, both the milled and the 3D-printed CD fared better than conventional dentures in terms of retention, reduction in the number of appointments, improved patient comfort, and improved predictable maintenance of the denture. Patients' perceptions and satisfaction were independent of the digital and conventional fabricated dentures.

Off-the-Shelf Tibial Cone Sizes May Not Accommodate All Patients' Bone Morphology and May Lead to Cortical Breaches in Revision Total Knee Arthroplasty: A 3D Modeling Study.

Background: In revision total knee arthroplasty, tibial cones have demonstrated improved longevity and reduced incidence of aseptic loosening. Several currently available "off-the-shelf" (OTS) cone systems may not have sizes to accommodate all patient bone morphologies. Methods: Computed tomographies from one hundred primary total knee arthroplasty patients and dimensions of 4 OTS cones were obtained. Press-fit stems were positioned in 3D tibia models to fit the diaphyseal trajectory. Cones were positioned around the stem at 1, 6, and 13 mm resections measured from the trough of the medial tibial plateau, simulating proximal tibial cuts and bone loss. Tibias were examined for cortical breaching following modeled cone preparation. Results: Increased rate of breaching was observed as size and depth of the cone increased. In 2/49 (4.1%) male and 19/46 (41.3%) female tibias, cones could not be positioned without breaching. No breaches were found in 22/49 (45.0%) male and 5/46 (10.9%) female tibias. For every 1 centimeter increase in patient height, odds of breaching decreased by 12% (odds ratio: 0.88, confidence interval: 0.84, 0.92). For every size increase in cone width, odds of breaching increased by 34% (odds ratio: 1.34, confidence interval: 1.28, 1.47). Placing cones deeper also increased breaching compared to the 1 mm cut. Conclusions: In revision total knee arthroplasty, smaller OTS or custom tibial cones may be needed to fit a patient's proximal tibial geometry. This is especially true in patients not accommodated by the OTS cone sizes we tested, which impacted shorter patients and/or those with substantial bone loss requiring more tibial resection and deeper cone placement. Use of smaller or custom tibial cones should be considered where indicated.

Verifying the seating of a 3D-printed removable die using elastomeric matrices: A dental technique.

Computer-aided design and computer-aided manufacturing systems enable digital designing and 3-dimensional (3D) printing of definitive casts with removable dies. However, the fit of the removable dies should be without interferences for their accurate positioning in the cast. Given that the accuracy of additive manufacturing depends on design- and manufacturing-related factors, verifying the accuracy of the position of 3D-printed removable dies in their cast is essential to fabricate positionally accurate definitive prostheses, which would enable minimal or no laboratory and clinical adjustments. This dental technique article presents a straightforward approach to verify the seating of a 3D-printed removable die by using verification matrices made of a polyvinylsiloxane interocclusal registration material.

Quality improvement exercises in Inflammatory Bowel Disease (IBD) services: A scoping review.

OBJECTIVE: Quality Improvement initiatives aim to improve care in Inflammatory Bowel Disease (IBD). These address a range of aspects of care including adherence to published guidelines. The objectives of this review were to document the scope and quality of published quality improvement initiatives in IBD, highlight successful interventions and the outcomes achieved. DESIGN/METHOD: We searched MEDLINE, EMBASE, CINAHL and Web of Science. Two reviewers independently screened and extracted data. We included peer reviewed articles or conference proceedings reporting initiatives intended to improve the quality of IBD care, with both baseline and prospectively collected follow-up data. Initiatives were categorised based on problems, interventions and outcomes. We used the Quality Improvement Minimum Quality Criteria Set instrument to appraise articles. We mapped the focus of the articles to the six domains of the IBD standards. RESULTS: 100 studies were identified (35 full text; 65 conference abstracts). Many focused on vaccination, medication, screening, or meeting multiple quality measures. Common interventions included provider education, the development of new service protocols, or enhancements to the electronic medical records. Studies principally focused on areas covered by the IBD standards 'ongoing care' and 'the IBD service', with less focus on standards 'pre-diagnosis', 'newly diagnosed', 'flare management', 'surgery' or 'inpatient care'. CONCLUSION: Good quality evidence exists on approaches to improve the quality of a narrow range of IBD service functions, but there are many topic areas with little or no published quality improvement initiatives. We highlight successful quality improvement interventions and offer recommendations to improve reporting of future studies.

Influence of exposure protocol, voxel size, and artifact removal algorithm on the trueness of segmentation utilizing an artificial-intelligence-based system.

PURPOSE: To evaluate the effects of exposure protocol, voxel sizes, and artifact removal algorithms on the trueness of segmentation in various mandible regions using an artificial intelligence (AI)-based system. MATERIALS AND METHODS: Eleven dry human mandibles were scanned using a cone beam computed tomography (CBCT) scanner under differing exposure protocols (standard and ultra-low), voxel sizes (0.15 mm, 0.3 mm, and 0.45 mm), and with or without artifact removal algorithm. The resulting datasets were segmented using an AI-based system, exported as 3D models, and compared to reference files derived from a white-light laboratory scanner. Deviation measurement was performed using a computer-aided design (CAD) program and recorded as root mean square (RMS). The RMS values were used as a representation of the trueness of the AI-segmented 3D models. A 4-way ANOVA was used to assess the impact of voxel size, exposure protocol, artifact removal algorithm, and location on RMS values (α = 0.05). RESULTS: Significant effects were found with voxel size (p < 0.001) and location (p < 0.001), but not with exposure protocol (p = 0.259) or artifact removal algorithm (p = 0.752). Standard exposure groups had significantly lower RMS values than the ultra-low exposure groups in the mandible body with 0.3 mm (p = 0.014) or 0.45 mm (p < 0.001) voxel sizes, the symphysis with a 0.45 mm voxel size (p = 0.011), and the whole mandible with a 0.45 mm voxel size (p = 0.001). Exposure protocol did not affect RMS values at teeth and alveolar bone (p = 0.544), mandible angles (p = 0.380), condyles (p = 0.114), and coronoids (p = 0.806) locations. CONCLUSION: This study informs optimal exposure protocol and voxel size choices in CBCT imaging for true AI-based automatic segmentation with minimal radiation. The artifact removal algorithm did not influence the trueness of AI segmentation. When using an ultra-low exposure protocol to minimize patient radiation exposure in AI segmentations, a voxel size of 0.15 mm is recommended, while a voxel size of 0.45 mm should be avoided.

Hierarchical assembly is more robust than egalitarian assembly in synthetic capsids.

Self-assembly of complex and functional materials remains a grand challenge in soft material science. Efficient assembly depends on a delicate balance between thermodynamic and kinetic effects, requiring fine-tuning affinities and concentrations of subunits. By contrast, we introduce an assembly paradigm that allows large error-tolerance in the subunit affinity and helps avoid kinetic traps. Our combined experimental and computational approach uses a model system of triangular subunits programmed to assemble into T = 3 icosahedral capsids comprising 60 units. The experimental platform uses DNA origami to create monodisperse colloids whose three-dimensional geometry is controlled to nanometer precision, with two distinct bonds whose affinities are controlled to kBT precision, quantified in situ by static light scattering. The computational model uses a coarse-grained representation of subunits, short-ranged potentials, and Langevin dynamics. Experimental observations and modeling reveal that when the bond affinities are unequal, two distinct hierarchical assembly pathways occur, in which the subunits first form dimers in one case and pentamers in another. These hierarchical pathways produce complete capsids faster and are more robust against affinity variation than egalitarian pathways, in which all binding sites have equal strengths. This finding suggests that hierarchical assembly may be a general engineering principle for optimizing self-assembly of complex target structures.

Discovery of N-benzyl-6-methylpicolinamide as a potential scaffold for bleaching herbicides.

BACKGROUND: In pesticide research, bleaching herbicides have always been a hot topic. Our previous research showed that N-(4-fluorobenzyl)-2-methoxybenzamide is an innovative lead compound for bleaching herbicides. RESULTS: A total of 40 derivatives of picolinamides were prepared and evaluated for their herbicidal activity by Petri dish tests and postemergence trials. The structure-activity relationship (SAR) revealed that introducing electron-withdrawing groups at the 3- or 4-positions of the benzyl significantly enhances herbicidal activity. Furthermore, ZI-04 induced similar symptoms such as bleaching effect in treated weeds and accumulation of biosynthetic precursors for carotenoids as observed with diflufenican. ZI-04 also exhibited significant cross-resistance to diflufenican and had a lower resistance risk than diflufenican. CONCLUSION: N-benzyl-6-methylpicolinamides were discovered as a novel scaffold for bleaching herbicides. The accumulation of phytoene, phytofluene and ζ-Carotene in radish cotyledons, and cross-resistance observed with diflufenican, showed that title compounds can interfere with carotenoid biosynthesis. © 2024 Society of Chemical Industry.

The Accuracy of Guided Implant Surgery With Different Fields of View of Cone-Beam Computerized Tomography.

Although a smaller size field of view (FOV) of cone-beam computerized tomography (CBCT) reduces radiation exposure, its effect on the accuracy of static computer-aided implant surgery (s-CAIS) remains unknown. This study aimed to evaluate the impact of the size of FOV on the accuracy of s-CAIS and to investigate if the arch affects this effect. A total of 32 implant sites on 8 identical scannable models (maxillae and mandibles) were randomly allocated to 2 FOV sizes: test (5 × 5 cm) and control (10 × 10 cm). All models were scanned with an intraoral scanner (IOS). With the registration of the surface scan and CBCT image, a prosthetic-driven implant position was planned. Following the fabrication of surgical templates, a single-blinded surgeon placed all implants with the fully guided s-CAIS protocol. IOS captured the implant positions with the scan body attached. Implant-planning software measured the angular deviation, 3-dimensional (3D) deviation at the crest, and 3D deviation at the apex between preplanned and actual implant positions. Two-way analysis of variance was used to analyze the effect of FOV and arch on the deviations. The size of FOV did not show a significant effect (P > .198) on angular deviation, 3D deviation at the crest, or 3D deviation at the apex. No significant difference was found when comparing the effect of the size of FOV between the maxillary and mandibular implants. In conclusion, the use of small FOV CBCT demonstrated comparable accuracy of s-CAIS to the use of medium FOV CBCT.

Platelet rich plasma therapy versus other modalities for treatment of plantar fasciitis: A systematic review and meta-analysis.

INTRODUCTION: Plantar fasciitis (PF) is the most common cause of heel pain in adults. There are numerous non-operative treatments available including platelet rich plasma (PRP) injections. PPR has demonstrated effectiveness for a range of musculoskeletal conditions including plantar fasciitis. PURPOSE/OBJECTIVE: To compare the effectiveness of PRP to other conservative treatment options for the management of PF. METHODS: A systematic search of PubMed and Google Scholar was performed for randomized control trials (RCT) comparing PRP to other treatment modalities. Studies met inclusion criteria if mean and standard deviations for visual analog scale (VAS) pain scores, plantar fascia thickness (PFT), Foot Function Index (FFI), or American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score were reported. Mean differences (MD) were used to compare VAS pain, PFT, FFI, and AOFAS between PRP and other treatments. RESULTS: Twenty-one RCTs which altogether included 1356 patients were included in the meta-analysis. PRP demonstrated significantly greater improvements in VAS pain scores compared to extracorporeal shock wave therapy (ESWT) (SMD: 0.86; CI: [0.30, 1.41]; p = 0.002), corticosteroid injections (CSI) (SMD: 1.08; CI: [0.05, 2.11]; p = 0.04), and placebo (SMD: 3.42; CI: [2.53, 4.31]; p < 0.00001). In terms of FFI, no significant differences existed among PRP, ESWT, CSI, dextrose prolotherapy (DPT), and meridian trigger points (MTP) in enhancing foot functionality. However, PRP demonstrated a marked advantage over phonophoresis, showing a substantial improvement in FFI scores (SMD: 3.07, 95% CI: 2.34-3.81). PRP did not demonstrate superiority over ESWT, CSI, or MTP for improving PFT, but it was notably more effective than phonophoresis (SMD: 3.18, 95% CI: 2.43-3.94). PRP demonstrated significantly greater improvements in AOFAS scores over CSI (SMD: 3.31, CI: [1.35, 5.27], p = 0.0009) and placebo (SMD: 3.75; CI: [2.81, 4.70]; p < 0.00001). CONCLUSION: PRP is more effective than CSI, ESWT, and placebo in reducing VAS and more effective than CSI and placebo in improving AOFAS. PRP did not demonstrate a consistent advantage across all outcome measures, such as PFT and FFI. These findings underscore the complexity of PF treatment and call for a more standardized approach to PRP preparation and outcome measurement. LEVEL OF EVIDENCE: Level I Meta-Analysis.

Microscopic interactions control a structural transition in active mixtures of microtubules and molecular motors.

Microtubules and molecular motors are essential components of the cellular cytoskeleton, driving fundamental processes in vivo, including chromosome segregation and cargo transport. When reconstituted in vitro, these cytoskeletal proteins serve as energy-consuming building blocks to study the self-organization of active matter. Cytoskeletal active gels display rich emergent dynamics, including extensile flows, locally contractile asters, and bulk contraction. However, it is unclear how the protein-protein interaction kinetics set their contractile or extensile nature. Here, we explore the origin of the transition from extensile bundles to contractile asters in a minimal reconstituted system composed of stabilized microtubules, depletant, adenosine 5'-triphosphate (ATP), and clusters of kinesin-1 motors. We show that the microtubule-binding and unbinding kinetics of highly processive motor clusters set their ability to end-accumulate, which can drive polarity sorting of the microtubules and aster formation. We further demonstrate that the microscopic time scale of end-accumulation sets the emergent time scale of aster formation. Finally, we show that biochemical regulation is insufficient to fully explain the transition as generic aligning interactions through depletion, cross-linking, or excluded volume interactions can drive bundle formation despite end-accumulating motors. The extensile-to-contractile transition is well captured by a simple self-assembly model where nematic and polar aligning interactions compete to form either bundles or asters. Starting from a five-dimensional organization phase space, we identify a single control parameter given by the ratio of the different component concentrations that dictates the material-scale organization. Overall, this work shows that the interplay of biochemical and mechanical tuning at the microscopic level controls the robust self-organization of active cytoskeletal materials.

Some Offset Restoration Options Can Paradoxically Lead to Decreased Range of Motion in Primary Total Hip Arthroplasty: A 3-Dimensional Computer Simulation Study.

BACKGROUND: In total hip arthroplasty (THA), femoral offset restoration results in optimal biomechanics and range of motion (ROM) without bone-bone impingement. We hypothesized that differences in implant design features significantly affect bone-bone impingement risk in primary THA. METHODS: This retrospective computer simulation study included a cohort of 43 primary robotic arm-assisted THA. Considering sagittal pelvic tilt, we measured the maximum external rotation at 0° hip flexion and the maximum internal rotation at both 90° and 100° hip flexion before any bone-bone impingement occurred. To influence the offset, we included neutral or extended polyethylene liners, neutral or plus prosthetic heads, standard or high-offset stems, and stems with 132° or 127° neck angles. RESULTS: Extended polyethylene liner use resulted in decreased bone-bone impingement for both stems but also decreased prosthetic ROM in hip extension (mean -4.5 to 5°, range -10 to 0°) and hip flexion (mean -3 to 3.7°, range -10 to 0°) due to decreases in head diameter. Using a plus head or different stem offset/neck angle options resulted in either (1) no improvement in ROM (stem 1: 60%; stem 2: 28%) or (2) a paradoxical increase in bone-bone impingement (stem 1 with 127°: 19% and stem 2 with high offset option: 7%). CONCLUSION: Counterintuitively, a subset of patients experience a paradoxical increase in bone-bone impingement when transitioning from standard to high-offset or varus necks due to the pelvic and proximal femoral bone shape. For this group of patients, preoperative personalized 3-dimensional modeling may help guide implant choice for optimizing outcomes.

Exploring the impact of the extent of the partially edentulous area on the accuracy of two intraoral scanners.

STATEMENT OF PROBLEM: The accuracy of intraoral scans, particularly in edentulous areas, remains a concern despite the increasing use of digital technology, especially intraoral scanners. PURPOSE: The purpose of this in vitro study was to assess the impact of the extent of an edentulous area on the accuracy (trueness and precision) of intraoral scans from 2 intraoral scanners. MATERIAL AND METHODS: A KaVo dentoform with epoxy resin teeth was used to generate 9 groups with different numbers of teeth removed. A laboratory scanner served as the reference dataset, and 2 intraoral scanners (TRIOS 3 and Primescan AC) were evaluated. A single operator performed all scans following standardized protocols and calibration. Trueness and precision were assessed by using root mean square (RMS) values. Analysis of variance was used to compare trueness and precision values obtained from the 2 scanners and different partially edentulous conditions (α=.05). RESULTS: A significant difference was found in the trueness of intraoral scans of the 2 scanners and under different partially edentulous extensions. Primescan AC exhibited significantly lower trueness than TRIOS 3 (P<.001). For the individual edentulous conditions, Primescan had a significantly higher RMS mean than TRIOS 3 for G0, G3, G4, G6, G7, and G8 (P<.001) and a significantly lower RMS mean than TRIOS 3 for G1 and G4 (P<.001), while no significant difference in RMS mean was found between the 2 scanners for G2 (P=.999). For precision, no significant difference was found between the 2 scanners or different edentulous conditions [(F 8, 90)=1.82, P=.085]. CONCLUSIONS: The accuracy of intraoral scans was influenced by the length of edentulous areas and the scanner used. Primescan AC demonstrated lower trueness than TRIOS 3 for most partially edentulous conditions, while the scanners were similar in precision. These findings highlight the need for careful scanner selection in specific clinical situations, as scanning accuracy may vary depending on the scanner and edentulous condition.

Surgical outcomes of hepatocellular carcinoma with extrahepatic bile duct tumor thrombus: a multicenter study.

Background: The long-term prognosis after surgery of patients with hepatocellular carcinoma (HCC) and extrahepatic bile duct tumor thrombus (Ex-BDTT) remains unknown. We aimed to identify the surgical outcomes of patients with HCC and Ex-BDTT. Methods: A total of 138 patients with Ex-BDTT who underwent hepatectomy with preservation of the extrahepatic bile duct from five large hospitals in China between January 2009 and December 2017 were included. The Cox proportional hazards model was used to analyze overall survival (OS) and recurrence-free survival (RFS). Results: With a median follow-up of 60 months (range, 1-127.8 months), the median OS and RFS of the patients were 28.6 and 8.9 months, respectively. The 1-, 3-, and 5-year OS rates of HCC patients with Ex-BDTT were 71.7%, 41.2%, and 33.5%, respectively, and the corresponding RFS rates were 43.5%, 21.7%, and 20.0%, respectively. Multivariate analysis identified that major hepatectomy, R0 resection, and major vascular invasion were independent prognostic factors for OS and RFS. In addition, preoperative serum total bilirubin ≥ 4.2 mg/dL was an independent prognostic factor for RFS. Conclusion: Major hepatectomy with preservation of the extrahepatic bile duct can provide favorable long-term survival for HCC patients with Ex-BDTT.