Factors Causing Unintended Sagittal and Axial Alignment Changes in High Tibial Osteotomy: Comparative 3-Dimensional Analysis of Simulation and Actual Surgery

BACKGROUND

Unintended secondary changes in the posterior tibial slope (PTS) and tibial torsion angle (TTA) may occur after medial open-wedge high tibial osteotomy (MOWHTO). In surgical procedures using patient-specific instruments (PSIs), it is essential to reproduce the PTS and TTA that were planned in simulations.

PURPOSE

To analyze the factors causing unintended sagittal and axial alignment changes after MOWHTO.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Overall, 63 patients (70 knees) who underwent MOWHTO using a PSI between June 2020 and June 2023 were retrospectively reviewed. Preoperative and postoperative computed tomography scans were 3-dimensionally reconstructed. Simulated osteotomy was performed so that the weightbearing line could pass through the target point. A PSI gapper was 3-dimensionally printed to fit the posteromedial corner of the osteotomy gap in the simulated HTO model. After MOWHTO using the PSI gapper, the actual postoperative model was compared with the preoperative or simulation model. This assessment included PTS, TTA, hinge axis, and osteotomy-related parameters. Cortical breakage around the lateral hinge was evaluated to assess stability.

RESULTS

The mean PTS and TTA did not change in the simulation. However, significant changes were observed in the actual postoperative PTS and TTA (change, -2.4°± 2.2° and -3.9°± 4.7°, respectively). The PTS was reduced, while the TTA decreased with internal rotation of the distal fragment. The difference in the axial hinge axis angle (AHA) between the simulation and actual surgery was the factor most correlated with the difference in the PTS (r = 0.625; P < .001). In regression analysis, the difference in the AHA was the only factor associated with the difference in the PTS (β = 0.558; P = .001), and there were no factors that showed any significant associations with the difference in the TTA. In subgroup analyses for the change in the TTA, the correction angle and anterior osteotomy angle were significantly higher in the more internal rotation group (P = .023 and P = .010, respectively). The TTA change was significantly higher in the unstable group with lateral cortical breakage (P = .018). The unstable group was more likely to show an internal rotation of ≥5° (odds ratio, 5.0; P = .007).

CONCLUSION

The AHA was associated with a difference in the PTS between the simulation and actual surgery. The change in the TTA was caused by a combination of multiple factors, such as a large correction angle and anterior osteotomy angle, but mainly by instability of the lateral cortical hinge.

Relationship between duration of atrial fibrillation and right heart structure remodeling as assessed by 3-dimensional transesophageal echocardiography

BACKGROUND

Tricuspid valve (TV) remodeling occurs in patients with atrial fibrillation (AF); however, the affecting factor related to TV remodeling in AF remains to be elucidated. We sought to explore whether the AF persistence itself affects right heart remodeling.

METHODS

A total of 372 lone AF patients (234 paroxysmal AF [paroxAF] and 138 persistent AF [persAF]) who underwent 3-dimensional transesophageal echocardiography (3D-TEE) was retrospectively reviewed. The duration from first-detected episode of AF to the TEE exam date was defined as AF duration.

RESULTS

PersAF patients had a larger TV area index (625.4 vs 719.0 mm2/m2; P < 0.001) and a higher right atrium area-to-right ventricle end-systolic area ratio (RA/RVESA ratio, 1.7 vs 1.9; P = 0.005) than paroxAF patients. The prevalence of AF-tricuspid regurgitation was higher in persAF than in paroxAF patients (1.3% vs 12.3%; P < 0.001). In persAF patients, AF duration was moderately correlated with TV diameter and 3D-TEE-derived TV annular area but not in paroxAF. On multivariable analysis, AF duration was independently associated with TV annular dilatation even after adjustment for RA/RVESA ratio and tricuspid regurgitation severity (β 0.37 [95% CI: 0.77-1.81]; P < 0.001). Additionally, AF duration with cutoff values of 20 months for predicting TV annular dilatation and 37 months for predicting RA/RVESA ratio > 2.1 had both high diagnostic accuracies among persAF patients (both P < 0.01).

CONCLUSIONS

AF duration itself is independently associated with right heart remodeling in persAF but not in paroxAF, such as TV annular dilatation and predominant RA remodeling which may lead to subsequent TR progression and adverse outcomes.

Prediction of 3-Dimensional Coverage Surface Area of the Femoral Head in Hip Dysplasia Through Conventional Computed Tomography

Background

Assessment of 3-dimensional (3D) femoral head coverage is critical in evaluating, preoperative planning, and treating hip dysplasia.

Purpose

To (1) propose a mathematical model to establish 3D femoral head coverage using conventional computed tomography (CT), (2) determine the correlation of 2D parameters with 3D coverage, and (3) characterize the patterns of dysplasia based on 3D morphology.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

We identified 30 patients (n = hips) with symptomatic dysplasia and 30 patients (n = hips) without dysplasia. Patients with dysplastic hips were matched with regard to sex, age, and body mass index to those with nondysplastic hips. Preoperative CTs were analyzed using 3D software, and 3D femoral head surface area coverage (FHSAC; in %) was assessed in 4 quadrant zones: anteromedial, anterolateral, posteromedial, and posterolateral. To assess lateral coverage of the femoral head, we introduced the anterolateral femoral head coverage angle (ALFC) and the posterolateral femoral head coverage angle (PLFC).

Results

Reduced femoral head coverage was more pronounced in dysplastic versus nondysplastic hips in the anterolateral quadrant (18% vs 40.7%, respectively) and posterolateral quadrant (35.8% vs 56.9%, respectively) (P < .0001 for both). Dysplastic hips had smaller ALFC and PLFC (18.4° vs 38.7°; P < .0001; 47.2° vs 72.3°; P = .0002). Anterolateral and posterolateral FHSAC were strongly correlated with the ALFC (r = 0.88; P < .0001) and the PLFC (r = 0.82; P < .0001) along with the lateral center-edge angle (anterolateral, r = 0.75; P < .0001; posterolateral, r = 0.73; P < .0001). Prediction models established for FHSAC had strong agreement with explanatory CT variables (anterolateral: r = 0.91; P < .0001; posterolateral: r = 0.90; P < .0001). The cutoff values for anterolateral and posterolateral FHSAC were 25% and 41%, respectively. In dysplastic hips, global deficiency was most common (15/30 hips), 9 hips showed an anterolateral deficiency, and 4 hips had a posterolateral deficiency pattern.

Conclusion

The ALFC and The PLFC were strongly correlated with 3D lateral FHSAC and were able to predict 3D coverage accurately.

The Ability to Sustain Facial Expressions

To gain more insight into facial muscle function, imaging during action would be optimal. Magnetic resonance imaging is highly suitable for visualizing facial muscles. However, magnetic resonance imaging requires the individual to remain as still as possible for a while. Knowledge of the ability to sustain facial expressions is requisite before scanning individuals. This could help adapting the scanning protocol to obtain optimal quality of imaging the muscles in action. A study, including 10 healthy volunteers, was done to perceive the extent of movement while holding facial expressions of smiling and pouting. During 6 minutes, 3-dimensional photographs were taken every consecutive minute while the participants maintained their facial expressions as motionless as possible. The movement was objectified by creating distance maps between the 2 models and calculating the Root Mean Square using the software 3DMedX. The results showed that most movements occurred in the first minute, with a decrease of the intensity of the expression. After the first minute, the expression, although less intense, could be held stable. This implies that magnetic resonance imaging scanning during facial expression is possible, provided that the scanning starts after the first minute has elapsed. In addition, results demonstrated that more slackening of the muscles while smiling compared with pouting.

Accreditation of the handheld 3-dimensional scanner and conventional photo images for area measurement

Accurate assessment of wound areas is crucial in making therapeutic decisions, as the prognosis and changes in the size of the wound over time play a significant role. An ideal assessment method should possess qualities such as speed, affordability, accuracy, user-friendliness for both patients and healthcare professionals, and suitability for daily clinical practice. This study aims to introduce a handheld 3-dimensional (3D) scanner and evaluate its accuracy in measuring wound areas. Engineers from the Industrial Technology Research Institute in Taiwan developed a handheld 3D scanner with the intention of extending its application to the medical field. A project was conducted to validate the accuracy of this 3D scanner. We utilized a smartphone (Asus ZenFone 2 with a 13-million-pixel rear camera), a digital single-lens reflex digital camera (Nikon, D5000, Tokyo, Japan), and the 3D scanner to repeatedly measure square papers of known size that were affixed to the curved surface of life-size facial mask or medical teaching breast models. The "Image J" software was employed for 2-dimensional image measurements, while the "3D Edit" software was used to assess the "area of interest" on 3D objects. By using square papers with predetermined dimensions, the measurement-associated error rate (ER) could be calculated for each image. Three repeated measurements were performed using the "Image J" software for each square paper. The ERs of the 3D scan images were all below 3%, with an average ER of 1.64% in this study. The close-up mode of the smartphone exhibited the highest ER. It was observed that as the area increased, the ER also increased in the digital single-lens reflex camera group. The extension distortion effect caused by the wide-angle lens on the smartphone may increase the ER. However, the definition of a healthy skin edge may vary, and different algorithms for calculating the measurement area are employed in various 3D measurement software. Therefore, further validation of their accuracy for medical purposes is necessary. Effective communication with software engineers and discussions on meeting clinical requirements are crucial steps in enhancing the functionality of the 3D scanner.

Three-Dimensional Morphological Study on the Effectiveness of Expanded Polytetrafluoroethylene Prosthesis in the Paranasal Augmentation

BACKGROUND

The paranasal depression is a common facial feature of Oriental populations. One of the most wildly used method to improve it was paranasal augmentation using expanded polytetrafluoroethylene (ePTFE). The effectiveness of it should be tested by three-dimensional morphological measurements.

METHODS

Patients who underwent paranasal augmentation using ePTFE between January 2017 and December 2022 were recruited in the study. The preoperative and postoperative clinical variables and three-dimensional measurement of patients were also collected. The satisfaction outcome were assessed.

RESULTS

By establishing a coordinate system based on the Frankfurt plane, 16 landmarks including nasal alar crest, subnasal point, upper lip, pogonion, glabella, sub-cheek, orbitale, tragion in left and right side of faces were marked. Five segments, 4 ratios, and 3 angles were measured based on it. The significant increase of segments, ratios, and angles indicated that paranasal augmentation could increase the protrusion of paranasal area, both in absolute value and relative proportion. The significant decrease of other data indicated that the protrusion difference between paranasal base and upper lip, forehead, and chin, respectively, were shortened after surgery. The average size of implant was 6.54 ± 1.02 mm, and the average increase of paranasal height was 4.38 ± 1.04 mm postoperatively. This indicates that two-thirds of its height will ultimately be reflected effectively in the sagittal elevation of the paranasal base.

CONCLUSIONS

Paranasal augmentation using ePTFE could effectively increase paranasal height and improve subunits relationships, and the ePTFE prosthesis should be designed and carve considering the 1/3 loss of height after implantation.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A Comparison of Three-Dimensional Visualization Systems and Two-Dimensional Visualization Systems During Laparoscopic Cholecystectomy: A Narrative Review

Background: Laparoscopic cholecystectomy is a common procedure for the definitive treatment for cholecystitis and symptomatic cholelithiasis. One advancement in minimally invasive surgery has been the development of three-dimensional (3D) visualization systems to provide stereopsis. It is yet to be determined whether this innovation is beneficial to the surgeon or simply just a gimmick. This narrative review aims to answer the following research question, what is the impact of 3D visualization systems on surgical efficiency compared with two-dimensional visualization systems in laparoscopic cholecystectomy? Methods: Through a broad literature search it was determined that operative time and intraoperative errors have been used in published research to assess intraoperative efficiency. Results: Studies published to date have used operative time, intraoperative errors, and intraoperative bleeding as current measures for intraoperative efficiency. Previous meta-analysis have shown a slight improvement in operative time for 3D visualization systems; however, subsequent randomized control trials have not shown a significant difference in operative time. Reporting of intraoperative errors has been quite subjective and a difference between visualisation modality has not been shown. Conclusion: 3D visualization systems have shown a minor improvement in operative time compared with traditional laparoscopic systems and it is unlikely to be of any clinical significance. Studies that measure intraoperative error vary greatly in what they report, and which assessment tool is used. Across existing literature, studies do not control for surgeon's experience, elective/emergent cases, and grade of gallbladder/difficulty. Further research is required, using novel tools for assessment in laparoscopic cholecystectomy to determine intraoperative differences through objective and quantitative variables.

Evaluation of Intraoperative Volumetric Assessment of Breast Volume Using 3D Handheld Stereo Photogrammetric Device

Methods for assessing three-dimensional (3D) breast volume are becoming increasingly popular in breast surgery. However, the precision of intraoperative volumetric assessment is still unclear. Until now, only non-validated scanning systems have been used for intraoperative volumetric analyses. This study aimed to assess the feasibility, handling, and accuracy of a commercially available, validated, and portable device for intraoperative 3D volumetric evaluation. All patients who underwent breast surgery from 2020 to 2022 were identified from our institutional database. Intraoperative 3D volumetric assessments of 103 patients were included in this study. Standardized 3D volumetric measurements were obtained 3 months postoperatively to compare the intraoperatively generated volumetric assessment. All of the study participants were women with a mean age of 48.3 ± 14.7 years (range: 20-89). The mean time for intraoperative volumetric assessment was 8.7 ± 2.6 min. The postoperative 3D volumetric assessment, with a mean volume of 507.11 ± 206.29 cc, showed no significant difference from the intraoperative volumetric measurements of 504.24 ± 276.61 cc (p = 0.68). The mean absolute volume difference between the intraoperative simulations and postoperative results was 27.1 cc. Intraoperative 3D volumetric assessment using the VECTRA H2 imaging system seems to be a feasible, reliable, and accurate method for measuring breast volume. Based on this finding, we plan to investigate whether volumetric objective evaluations will help to improve breast symmetry in the future.

Glioblastoma modeling with 3D organoids: progress and challenges

Glioblastoma (GBM) is the most aggressive adult primary brain tumor with nearly universal treatment resistance and recurrence. The mainstay of therapy remains maximal safe surgical resection followed by concurrent radiation therapy and temozolomide chemotherapy. Despite intensive investigation, alternative treatment options, such as immunotherapy or targeted molecular therapy, have yielded limited success to achieve long-term remission. This difficulty is partly due to the lack of pre-clinical models that fully recapitulate the intratumoral and intertumoral heterogeneity of GBM and the complex tumor microenvironment. Recently, GBM 3D organoids originating from resected patient tumors, genetic manipulation of induced pluripotent stem cell (iPSC)-derived brain organoids and bio-printing or fusion with non-malignant tissues have emerged as novel culture systems to portray the biology of GBM. Here, we highlight several methodologies for generating GBM organoids and discuss insights gained using such organoid models compared to classic modeling approaches using cell lines and xenografts. We also outline limitations of current GBM 3D organoids, most notably the difficulty retaining the tumor microenvironment, and discuss current efforts for improvements. Finally, we propose potential applications of organoid models for a deeper mechanistic understanding of GBM and therapeutic development.

Short- to Mid-term Results of Patient-Specific Polymethylmethacrylate Radial Head Prosthesis in Complex Radial Head Fractures Using 3-Dimensional Mold System

Background: We used antibiotic-impregnated polymethylmethacrylate (PMMA) bone cement to make a patient-specific radial head prosthesis (RHP) by applying the 3-dimensional (3D) designing technique in patients with Mason types 3 and 4 radial head fractures. The aim of this study is to report the short- to mid-term outcomes of this procedure. Methods: This is a prospective study of all patients who underwent a patient-specific PMMA bone cement RHP at our institute over a 1-year period from May 2017 to June 2018. The outcome measures included range of motion, grip strength, visual analogue scale (VAS) for pain at rest and at activity, disabilities of arm, shoulder and hand (DASH) score and Mayo elbow performance index (MEPI). Radiographs of the elbow ere obtained at final follow-up and any complications were also recorded. Results: Our study included eight patients with a mean follow-up of 18 months (13-20 months). The mean arc of extension-flexion and supination-pronation of the operated side was 86% and 96% of the unaffected side, respectively. Mean grip strength was 86% of the unaffected side. The mean VAS for pain at rest was 0 and during activity was 2 out of 10. The mean DASH score was 8 out of 100 (0-22), showing minimal disability and ability to cope with most living activities. MEPI showed four excellent, three good and one fair result. One patient complained of proximal forearm pain that appeared 1 year after surgery. No patient complained of ulnar nerve symptoms requiring intervention. No RHP was removed during the follow-up. Conclusions: PMMA RHP can be used safely as an alternative to metal prostheses to restore valgus and axial stability of the forearm. The use of 3D printing optimised the design and surgical technique of radial head arthroplasty, and we need further studies to assess the long-term follow-ups. Level of Evidence: Level IV (Therapeutic).

Automated Macular Fluid Volume As a Treatment Indicator for Diabetic Macular Edema

Introduction: To assess the diagnostic accuracy of automatically quantified macular fluid volume (MFV) for treatment-required diabetic macular edema (DME). Methods: This retrospective cross-sectional study included eyes with DME. The commercial software on optical coherence tomography (OCT) produced the central subfield thickness (CST), and a custom deep-learning algorithm automatically segmented the fluid cysts and quantified the MFV from the volumetric scans of an OCT angiography system. Retina specialists treated patients per standard of care based on clinical and OCT findings without access to the MFV. The main outcome measures were the area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity of the CST, MFV, and visual acuity (VA) for treatment indication. Results: Of 139 eyes, 39 (28%) were treated for DME during the study period and 101 (72%) were previously treated. The algorithm detected fluid in all eyes; however, only 54 eyes (39%) met the DRCR.net criteria for center-involved ME. The AUROC of MFV predicting a treatment decision of 0.81 was greater than that of CST (0.67) (P = .0048). Untreated eyes that met the optimal threshold for treatment-required DME based on MFV (>0.031 mm3) had better VA than treated eyes (P = .0053). A multivariate logistic regression model showed that MFV (P = .0008) and VA (P = .0061) were significantly associated with a treatment decision, but CST was not. Conclusions: MFV had a higher correlation with the need for treatment for DME than CST and may be especially useful for ongoing management of DME.

A case report of primary complex anal fistula with 7 external openings treated with combined preoperative 3D MRI model

INTRODUCTION

Anal fistula is a common perianal disease, but primary complex anal fistulas with 7 external openings is extremely rare.

PATIENT CONCERNS

We report a case of a 36-year-old man with a 10-year history of recurrent pus flow from paranal mass.

DIAGNOSIS

Primary complex anal fistula.

INTERVENTIONS

The patient underwent fistulotomy plus seton, which we successfully completed with the aid of 3-dimensional (3D) reconstruction model created from magnetic resonance imaging (MRI).

OUTCOMES

The wound healed well and there was no recurrence 8 months after surgery.

CONCLUSION

In the treatment of complex anal fistula, the combined application of 3D MRI model will be beneficial to obtain better surgical results.

Patient derived glioma stem cell spheroid reporter assays for live cell high content analysis

Three dimensional models of cell culture enables researchers to recreate aspects of tumour biology not replicated by traditional two dimensional techniques. Here we describe a protocol to enable automated high throughput phenotypic profiling across panels of patient derived glioma stem cell spheroid models. We demonstrate the use of both live/dead cell end-points and monitor the dynamic changes in the cell cycle using cell lines expressing the FUCCI cell cycle reporter. Together, these assays provide additional insight into the mechanism of action of compound treatments over traditional cell viability assay endpoints.

Utilizing 3-Dimensional Cardiac Models With Point-of-Care Ultrasound Video Tutorials to Improve Medical Student Education: A Double-Blinded Randomized Control Study

Introduction Ultrasound is a rapidly expanding imaging modality that many medical schools are incorporating into a structured curriculum. Learning both anatomy and ultrasound imaging simultaneously is intuitively challenging. This double-blinded, randomized control study examined the effect of utilizing three-dimensional (3d) cardiac models within an ultrasound video tutorial in order to achieve improved cardiac ultrasound anatomy education. Methods Thirty-nine (39) first- and second-year medical students at a single medical school voluntarily participated. The control group watched a video tutorial on cardiac ultrasound anatomy while the experimental group watched a similar video tutorial that also included a 3d cardiac model. The effect was measured with a multiple-choice test that included a sub-analysis of ultrasound principles. The test was unique in that no text or context clues were provided on the reference images, further challenging anatomic identification. Results The findings of the study included a p-value of 0.73 for the ultrasound principles section and a p-value of 0.77 for the cardiac anatomy. There was no statistical difference in the primary outcome or in the subgroup analysis. Post-hoc analysis demonstrated the study was underpowered. Conclusions This study is the first of its kind to utilize an innovative testing method that holds promise for future research in regards to utilizing 3d models with ultrasound education. The study was underpowered, therefore no definitive conclusions about the utility of 3d cardiac models in the educational process can be ascertained.

Acetabular coverage analysis of the proximal femoral head accurately characterizes dysplastic acetabular morphology

This study aimed to (1) measure acetabular sector angle (ASA) from proximal to distal positions along the axial femoral head axis, (2) identify acetabular deficiency patterns, and (3) correlate ASA at different axial positions with other radiological measurements in acetabular dysplasia. We identified 30 hips with dysplasia (lateral center edge angle [LCEA] <20°) and 30 hips without dysplasia (LCEA >25°) from a retrospective cohort. Anterior and posterior ASA (AASA, PASA) were measured in the axial computed tomography plane through the femoral head center (equatorial) and two axial positions above the equatorial line (intermediate and proximal). Deficiency patterns were identified using ASA cut-off values determined from receiver operating characteristic curves. Pearson's coefficients were used for correlations. Compared to non-dysplastic hips, AASA in dysplastic hips was significantly smaller in all levels: equatorial (46.1 ± 7.3 vs. 54.9 ± 8.5,° p < 0.001), intermediate (62.1 ± 11.2 vs. 69.0 ± 10.6,° p = 0.02), and proximal (102.9 ± 14.2 vs. 128.3 ± 23.0,° p < 0.001). According to proximal ASA (Pro-ASA) cut-off values in dysplastic hips, global deficiency was most prevalent (19/30, 63.3%), followed by anterior (6/30, 20%) and posterior (3/30, 10%) deficiency. There were strong correlations between acetabular anteversion and Eq-AASA (r = -0.74, p < 0.001) and LCEA and pro-PASA (r = 0.82, p < 0.001). Clinical significance: Acetabular sector angle provides insight into acetabular morphology and patterns of deficiency, providing essential information for precise acetabular reorientation.

Dorsal medulla surface texture: Differentiating neuromyelitis optica spectrum disorder from multiple sclerosis

BACKGROUND AND PURPOSE

The timely and accurate diagnosis of neuromyelitis optica spectrum disorder (NMOSD) is essential and exposure to multiple sclerosis (MS) disease-modifying therapies may result in permanent neurological disability.

METHODS

Standardized 3-Tesla 3-dimensional brain MRI studies were retrospectively studied from people with NMOSD, MS, other CNS neurological diseases, and healthy control subjects. Comparisons of surface texture characteristics at the area postrema involving absolute introverted planar triangle counts, representing more complex and concave tissue topography, along with the spatial dissemination pattern of these triangles were performed cross-sectionally and longitudinally. An ideal introverted planar triangle threshold separating groups with NMOSD and MS was accomplished using the highest Youden's J statistic. For the classification of NMOSD, out-of-sample and in-sample measurements of the following were acquired: sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

The study cohort included 60 people with NMOSD, 100 people with MS, 12 with other neurological diseases, and five healthy controls. Significantly higher cross-sectional median introverted triangle counts were observed when the NMOSD (median [interquartile range]: 100 [23.5]) group was compared to MS (65 [20.25]; p < .0001) and other neurological diseases (66 [13.75]; p < .0001). Distinct spatial dissemination patterns of triangles extending craniocaudally at the region of interest within the dorsal medulla was also seen between groups with NMOSD and MS (p < .0001). For the identification of NMOSD, out-of-sample sensitivity (83%), specificity (100%), PPV (100%), and NPV (60%) were achieved.

CONCLUSIONS

Cross-sectional and longitudinal dorsal medulla surface texture differences within selective regions of vulnerability differentiate NMOSD from MS.

No difference in gait pattern between a short collum femoris-preserving and a conventional stem: 44 randomised total hip arthroplasty patients stem evaluated after 2 years

BACKGROUND

The uncemented collum femoris-preserving (CFP) stem offers preservation of the femoral neck and a more conservative soft tissue resection, which may facilitate a more normal walking pattern. We used gait analysis to evaluate if patients operated with a CFP stem showed more favourable hip kinematics and kinetics when compared with a group of patients operated with a conventional uncemented stem.

METHODS

44 patients randomised to receive either a CFP or a Corail stem were studied and were operated using a direct lateral incision. Gait analysis was performed 2 years after the operation with a 12-camera motion capture system and 2 force plates. Hip kinematics and kinetics were analysed and 66 subjects served as controls.

RESULTS

None of the variables: speed, stride, cadence and stance showed any statistical significant difference between the 2 study groups. Neither did the hip kinematics and kinetics. Compared to controls, patients operated with the CFP stem showed an increased stance (62.5% vs. 61.1%, p < 0.006) and decreased hip abduction (-2.1° vs. -6.5°). Patients operated with the Corail stem showed decreased speed (1.18 vs. 1.23 m/second), and stride length (1.26 vs. 1.33 m), decreased hip extension (-7.5° vs. -12.8°) and range of hip flexion/extension (38° vs. 40.9°), as well as their hip adduction that was increased (6.3° vs. 4°), whereas their hip abduction was reduced (-2.8° vs. -6.5°), (p < 0.004) compared to the controls.

CONCLUSIONS

Use of a CFP stem did not significantly influence any of the gait parameters studied when compared to a standard stem, but still both stems studied were associated with gait deviations when compared to controls. Whether these differences could be attributed to the stem used, the underlying hip disease, or both is still unknown.

Deep Learning-Based Prediction of the 3D Postorthodontic Facial Changes

With the increase of the adult orthodontic population, there is a need for an accurate and evidence-based prediction of the posttreatment face in 3 dimensions (3D). The objectives of this study are 1) to develop a 3D postorthodontic face prediction method based on a deep learning network using the patient-specific factors and orthodontic treatment conditions and 2) to validate the accuracy and clinical usability of the proposed method. Paired sets (n = 268) of pretreatment (T1) and posttreatment (T2) cone-beam computed tomography (CBCT) of adult patients were trained with a conditional generative adversarial network to generate 3D posttreatment facial data based on the patient's gender, age, and the changes of upper (ΔU1) and lower incisor position (ΔL1) as input. The accuracy was calculated with prediction error and mean absolute distances between real T2 (T2) and predicted T2 (PT2) near 6 perioral landmark regions, as well as percentage of prediction error less than 2 mm using test sets (n = 44). For qualitative evaluation, an online survey was conducted with experienced orthodontists as panels (n = 56). Overall, PT2 indicated similar 3D changes to the T2 face, with the most apparent changes simulated in the perioral regions. The mean prediction error was 1.2 ± 1.01 mm with 80.8% accuracy. More than 50% of the experienced orthodontists were unable to distinguish between real and predicted images. In this study, we proposed a valid 3D postorthodontic face prediction method by applying a deep learning algorithm trained with CBCT data sets.

Exploring complement-dependent cytotoxicity by rituximab isotypes in 2D and 3D-cultured B-cell lymphoma

Background

The therapeutic IgG1 anti-CD20 antibody, rituximab (RTX), has greatly improved prognosis of many B-cell malignancies. Despite its success, resistance has been reported and detailed knowledge of RTX mechanisms are lacking. Complement-dependent cytotoxicity (CDC) is one important mode of action of RTX. The aim of this study was to systematically evaluate factors influencing complement-mediated tumor cell killing by RTX.

Methods

Different RTX isotypes, IgG1, IgG3, IgA1 and IgA2 were evaluated and administered on four human CD20⁺ B-cell lymphoma cell lines, displaying diverse expression of CD20 and complement-regulatory protein CD59. Complement activation was assessed on lymphoma cells grown in 2 and 3-dimensional (3D) culture systems by trypan blue exclusion. CDC in 3D spheroids was additionally analyzed by Annexin V and propidium iodide staining by flow cytometry, and confocal imaging. Anti-CD59 antibody was used to evaluate influence of CD59 in RTX-mediated CDC responses. Statistical differences were determined by one-way ANOVA and Tukey post hoc test.

Results

We found that 3 out of 4 lymphomas were sensitive to RTX-mediated CDC when cultured in 2D, while 2 out of 4 when grown in 3D. RTX-IgG3 had the greatest CDC potential, followed by clinical standard RTX-IgG1 and RTX-IgA2, whereas RTX-IgA1 displayed no complement activation. Although the pattern of different RTX isotypes to induce CDC were similar in the sensitive lymphomas, the degree of cell killing differed. A greater CDC activity was seen in lymphoma cells with a higher CD20/CD59 expression ratio. These lymphomas were also sensitive to RTX when grown in 3D spheroids, although the CDC activity was substantially reduced compared to 2D cultures. Analysis of RTX-treated spheroids demonstrated apoptosis and necrosis essentially in the outer cell-layers. Neutralization of CD59 overcame resistance to RTX-mediated CDC in 2D-cultured lymphoma cells, but not in spheroids.

Conclusions

The results demonstrate that CDC outcome in CD20⁺ B-cell lymphoma is synergistically influenced by choice of RTX isotype, antigen density, tumor structure, and degree of CD59 expression. Assessment of tumor signatures, such as CD20/CD59 ratio, can be advantageous to predict CDC efficiency of RTX in vivo and may help to develop rational mAbs to raise response rates in patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09772-1.

MRI-based 3-dimensional volumetric assessment of fatty infiltration and muscle atrophy in rotator cuff tears

BACKGROUND

The Goutallier and Warner Classification systems are useful in determining rotator cuff reparability. Data are limited on how accurately the scapular-Y view used in both systems reflects the 3-dimensional (3-D) changes in fatty infiltration (FI) and muscle atrophy (MA). Tendon retraction in the setting of a cuff tear may also influence the perception of these changes. This study's objectives were to (1) measure the 3-D volume of the supraspinatus muscle in intact rotator cuffs, and with varying magnitudes of retraction; (2) measure the 3-D volume of FI in the supraspinatus muscle in these conditions; and (3) determine the influence of tendon retraction on measured FI and MA using the Goutallier and Warner Classification Systems.

METHODS

Between August 2015 and February 2016, all shoulder magnetic resonance images (MRIs) at the Portland VA Medical Center were standardized to include the medial scapular border. MRIs and charts were reviewed for inclusion/exclusion criteria. Included MRIs were categorized into 4 groups based on rotator cuff retraction. Supraspinatus muscle and fossa were traced to create 3-D volumes. FI and MA were measured within the supraspinatus. The supraspinatus muscle was graded among 6 physicians using the Goutallier and Warner classification systems. These grades were compared to 3-D measured FI and MA. The influence of tendon retraction on the measured grades were also evaluated.

RESULTS

One hundred nine patients met inclusion/exclusion criteria. Ten MRIs for each group (N = 40) were included for image analysis. Supraspinatus volume tracings were highly reproducible and consistent between tracers. Supraspinatus muscle volumes decreased while global FI and MA increased with greater degrees of tendon retraction. In muscles with less than 10% global fat, fat concentrated in the lateral third of the muscle. In muscle with more than 10% global fat content, it distributed more diffusely throughout the muscle from medial to lateral. In comparing the scapular-Y to a medial cut, there was no consistent trend in FI whereas MA was more accurate at the medial cut.

CONCLUSION

Parasagittal imaging location did not significantly influence the Goutallier score; however, assessment of MA using the Warner score leads readers to perceive less MA medially regardless of the magnitude of tendon retraction. The pattern of FI within the supraspinatus muscle changes from a laterally based location around the muscle-tendon junction to a more diffuse, global infiltration pattern when the whole muscle fat content exceeds 10%.

Use of the 3D exoscope for the supracerebellar infratentorial approach in the concorde position: an effective and ergonomic alternative. Illustrative cases

BACKGROUND

The supracerebellar infratentorial approach provides wide flexibility as a far-reaching corridor to the pineal region, posterior third ventricle, posterior medial temporal lobe, posterolateral mesencephalon, quadrigeminal cistern, and thalamus. Traditionally, the patient is placed in the sitting position, allowing gravity retraction on the cerebellum to widen the supracerebellar operative corridor beneath the tentorium. What this approach gains in anatomical orientation it lacks in surgeon ergonomics, as the sitting position presents technical challenges, forces the surgeon to adopt to an uncomfortable posture while performing the microsurgical dissection/tumor resection under the microscope, and is also associated with an increased risk of venous air embolism.

OBSERVATIONS

In this article, the authors present the use of the three-dimensional (3D) exoscope with a standard prone Concorde position as an alternative for the treatment of lesions requiring a supracerebellar infratentorial approach for lesions in the pineal region, posterior third ventricle, and the superior surface of the cerebellar vermis. The authors present four illustrative cases (one pineal cyst, one ependymoma, and two cerebellar metastases) in which this approach provided excellent intraoperative visualization and resulted in good postoperative results. A step-by-step description of our surgical technique is reviewed in detail.

LESSONS

The use of the 3D exoscope with the patient in the prone Concorde position is an effective and ergonomically favorable alternative to the traditional sitting position for the treatment of lesions requiring a supracerebellar infratentorial approach. This technique allows improved visualization of deep structures, with a possible decreased risk of potential complications.

Anterior vertebral body tethering for thoracic idiopathic scoliosis leads to asymmetric growth of the periapical vertebrae

PURPOSE

To evaluate 3D growth of the periapical vertebrae and discs in the 2 years after anterior vertebral body tether (AVBT) placement in patients with idiopathic scoliosis (IS).

METHODS

Patients with IS treated with AVBT, ≥ 2 years of follow-up, and 3D spine reconstructions created from simultaneous, biplanar radiographs were studied. Patients were divided into two groups: progressive scoliosis correction (PC) or no/limited correction (NPC). The average of the 3 apical vertebral and disc heights and angular measures were made. The rate of change for each measure (mm/mo, °/mo) from first erect to 2-year follow-up was compared between groups.

RESULTS

Fourteen (Risser 0, Sanders 2-3) patients aged 11.4 ± 1.4 years with right thoracic scoliosis of 52 ± 9° were included. There were 7 patients per group (6F, 1M). Mean follow-up was 3.6 ± 1.1 (range 2-5) years. PC left-sided vertebral height increased 0.13 mm/months compared to 0.05 mm/mo in the NPC group (p = 0.001). Right (tethered side) vertebral growth was not different (PC: 0.07 mm/mo, NPC: 0.05 mm/mo, p = 0.2). Coronal vertebral wedging occurred at - 0.11°/mo compared to - 0.02°/mo for the PC and NPC groups, respectively (p = 0.004). Coronal disc angulation change was - 0.12°/mo in the PC group and - 0.04°/mo in the NPC group (p = 0.03), and was associated with loss of right disc height (PC: - 0.06 mm/mo) with little effect on the left disc height (PC: -0.01 mm/mo).

CONCLUSIONS

AVBT in immature patients with thoracic scoliosis can asymmetrically modulate growth of the periapical vertebrae and discs. Progressive reduction in scoliosis after AVBT was associated with greater concave growth rates in the vertebrae and loss of disc height on the convex side.

Direction and magnitude of displacement differ between slowly expanding and non-expanding multiple sclerosis lesions as compared to small vessel disease

BACKGROUND AND PURPOSE

Differentiating between multiple sclerosis (MS) and small vessel disease (SVD) lesions represents a key challenge in the day-to-day management of patients. We aimed to distinguish between MS and SVD by identifying the dynamics of lesion movement patterns between enlarging and contracting foci from two MRI time points.

METHODS

Standardized 3-Tesla 3-dimensional brain magnetic resonance imaging (MRI) studies were performed at two time points on enrolled MS and SVD patients. Selected supratentorial lesions were segmented and longitudinal changes in the direction of lesion displacement and magnitude along with the evolution of contracting and expanding T1-weighted and T2-weighted MS lesions were quantified based on lesion centroid positioning. Bayesian linear mixed effects regression models were constructed to evaluate associations between changes in lesion transitions and disease state.

RESULTS

A total of 420 lesions were analyzed from 35 MS (female (F):22 (62.9%); median age (range):38 years (y) (22-61), median disease duration:7.38y (0.38-20.99)) and 12 SVD patients (F:11 (100%); 54y (40-66)). MS T2-weighted lesions that increased in volume between MRI time points demonstrated movement toward the cortex (p = 0.01), whereas those that decreased in volume moved toward the center (p < 0.0001). Lesion volume changes related to SVD demonstrated no effect on movement direction over time. Both expanding (p = 0.03) and contracting (p = 0.01) MS lesions demonstrated greater distances between centroids when compared to SVD.

CONCLUSION

Lesion dynamics may reveal distinct characteristics associated with the biology of disease while providing further insights into the behavior of inflammatory CNS disorders.

Fetuin-A Promotes 3-Dimensional Growth in LNCaP Prostate Cancer Cells by Sequestering Extracellular Vesicles to Their Surfaces to Act as Signaling Platforms

The present studies were conducted to evaluate key serum proteins and other components that mediate anchorage-independent growth (3-D growth) of LNCaP prostate cancer cells as spheroids. The cells were cultured on ultra-low attachment plates in the absence and presence of fetuin-A and with or without extracellular vesicles. The data show that fetuin-A (alpha 2HS glycoprotein) is the serum protein that mediates 3-D growth in these cells. It does so by sequestering extracellular vesicles of various sizes on the surfaces of rounded cells that grow as spheroids. These vesicles in turn transmit growth signals such as the activation of AKT and MAP kinases in a pattern that differs from the activation of these key growth signaling pathways in adherent and spread cells growing in 2-D. In the process of orchestrating the movement and disposition of extracellular vesicles on these cells, fetuin-A is readily internalized in adhered and spread cells but remains on the surfaces of non-adherent cells. Taken together, our studies suggest the presence of distinct signaling domains or scaffolding platforms on the surfaces of prostate tumor cells growing in 3-D compared to 2-D.

Remote Surgeon Virtual Presence: A Novel Telementoring Method for Live Surgical Training

PURPOSE

We describe the first known use of telementoring in corneal surgery and technology combining a 3-dimensional microscope system, 5G live streaming technology, group chat software, and a virtual reality headset for intercontinental surgical supervision.

METHODS

Three surgeons in Toronto were proctored by a surgeon in Israel in the implantation of a novel keratoprosthesis device (CorNeat KPro; Ra'anana, Israel) into cadaver eyes. In Toronto, the NGENUITY platform (Alcon) transmitted high-definition, 3-dimensional images to the proctor in Israel who viewed the live video through a GOOVIS Virtual Reality headset with subsecond latency. This was made possible by the LiveU technology (Hackensack, NJ), which is a portable device to increase the bandwidth of transmission. The primary outcome was the successful completion of CorNeat KPro implantation. After each procedure, all surgeons completed a Likert scale questionnaire that assessed opinions on telementoring.

RESULTS

All participants implanted the CorNeat KPro device. There was significant satisfaction reported. A total cumulative score from the questionnaire was 149 of 150 from the operating surgeons, with a score of 135 of 150 by the proctor. All felt that there was excellent AV quality with no lag time and recommended the technology.

CONCLUSIONS

Telementoring is a promising tool that can traverse large distances for ophthalmic education.

Micro-Computed Tomography-Based Three-Dimensional Anatomical Structure of the Region Around the Pterygoid Hamulus

OBJECTIVE

Palatoplasty would involve the structures around the pterygoid hamulus. However, clinicians hold different opinions on the optimal approach for the muscles and palatine aponeurosis around the pterygoid hamulus. The absence of a consensus regarding this point can be attributed to the lack of investigations on the exact anatomy of this region. Therefore, we used micro-computed tomography to examine the anatomical structure of the region surrounding the pterygoid hamulus.

DESIGN

Cadaveric specimens were stained with iodine-potassium iodide and scanned by micro-computed tomography to study the structures of the tissues, particularly the muscle fibers. We imported Digital Imaging and Communications in Medicine images to Mimics to reconstruct a 3-dimensional model and simplified the model.

RESULTS

Three muscles were present around the pterygoid hamulus, namely the palatopharyngeus (PP), superior constrictor (SC), and tensor veli palatini (TVP). The hamulus connects these muscles as a key pivot. The TVP extended to the palatine aponeurosis, which bypassed the pterygoid hamulus, and linked the PP and SC. Some muscle fibers of the SC originated from the hamulus, the aponeurosis of which was wrapped around the hamulus. There was a distinct gap between the pterygoid hamulus and the palatine aponeurosis. This formed a pulley-like structure around the pterygoid hamulus.

CONCLUSIONS

Transection or fracture of the palatine aponeurosis or pterygoid hamulus, respectively, may have detrimental effects on the muscles around the pterygoid hamulus, which play essential roles in the velopharyngeal function and middle ear ventilation. Currently, cleft palate repair has limited treatment options with proven successful outcomes.

Changes in peri-apical vertebral body and intervertebral disc shape in both the sagittal and coronal planes correlate with scoliosis severity: a 3D study of 397 patients

PURPOSE

To evaluate associations between vertebrae and disc shape asymmetry and adolescent idiopathic scoliosis (AIS) curve severity.

METHODS

Analysis included normal screening referrals and patients with right, main thoracic AIS who underwent upright, biplanar radiographs with 3D reconstruction at a single institution from 2010 to 2015. Peri-apical anterior, posterior, right, and left vertebral body heights (aVBH, pVBH, rVBH, lVBH) and intervertebral disc heights (DH) were measured, and ratios of these measurements were calculated in sagittal and coronal planes. Correlations were performed between curve severity and height measurements. Sagittal and coronal plane components of these measurements were compared between normal controls with coronal curve measurements < 11° and patients with moderate (11°-49°) and severe curves (≥ 50°), with tolerance intervals established for the normal controls.

RESULTS

The analysis included a total of 397 patients. Patients with AIS had coronal curve measurements ranging from 11° to 101°. Greater coronal curve severity strongly correlated with smaller pVBH relative to aVBH and moderately correlated with smaller pDH relative to aDH (r = - 0.643, r = - 0.305, respectively). aVBH was greater for larger curves; pVBH remained stable. Scoliosis severity strongly correlated with right relative to left VBH and DH ratios (r = 0.919, r = 0.865 respectively). In comparison of normal controls to severe curves, severe curves had significantly greater aVBH and aDH, while pVBH was not significantly different and pDH was significantly less. Nearly half (46.9%) of the severe curves were below the range of normal for PA vertebral height ratio.

CONCLUSION

In right, main thoracic AIS, greater main thoracic curve severity is associated with greater sagittal and coronal plane asymmetry of both the vertebral bodies and the discs. Severity more strongly correlates with vertebral changes in symmetry than with disc changes, though both are present.

Role of 3D echocardiography-determined atrial volumes in distinguishing between pre-capillary and post-capillary pulmonary hypertension

Aims

The current guidelines on pulmonary hypertension (PH) recommend the use of invasive examination for differentiating between left‐sided heart disease‐related (post‐capillary) and pre‐capillary PH. However, atrial sizes are considered markers of ventricular filling pressures. Therefore, we aimed to test the clinical applicability of atrial volumes measured by transthoracic three‐dimensional echocardiography (3DE) in differentiating between pre‐capillary and post‐capillary PH.

Methods and results

Seventy‐five consecutive patients with PH were prospectively examined with transthoracic 3DE. After less than 24 h, the patients underwent right heart catheterization and 3DE and were classified as pre‐capillary or post‐capillary PH according to the recommendations of the ESC guidelines. The atrial volumes were measured offline with dedicated commercial software. Thirty‐eight patients (13 men, age 65 ± 18 year) had pre‐capillary PH, and 37 (23 men, age 62 ± year) had post‐capillary PH. The mean pulmonary artery pressures were similar in patients with pre‐capillary and post‐capillary PH (38 [IQR 26, 54] mmHg vs. 41 [IQR 33, 48] mmHg, respectively, P = 0.49). The left atrial indexed maximum (LAVi max) and minimum (LAVi min) volumes were significantly larger in the post‐capillary PH patient group than in the pre‐capillary PH patient group (LAVi max: 64 ± 32 mL/m² vs. 41 ± 25 mL/m², P = 0.001; LAVi min: 50 ± 22 mL/m² vs. 26 ± 24 mL/m², P < 0.0001). The indexed right atrial minimum volume (RAVi min) was also higher in patients with post‐capillary PH (51 ± 27 mL/m² vs. 38 ± 26 mL/m²; P = 0.02). Both the left atrial (LA) and right atrial (RA) volumes, especially the LA minimum volume, correlated with the pulmonary artery wedge pressure (PAWP) (r = 0.62 (P < 0.0001) for LAV min vs. r = 0.49 (P < 0.0001) for LAV max; r = 0.32 (P = 0.005) for RAV min vs. r = 0.24 (P = 0.04) for RAV max). Multivariate logistic regression analysis showed that LAVi min was an independent predictor of post‐capillary PH. In the receiver operating characteristic (ROC) curves of parameters predicting the post‐capillary PH, the areas under the curve (AUC) for LAVi min, LAVi max, and RAVi min were 0.86 (95% CI, 0.76–0.95), 0.78 (95% CI, 0.67–0.89), and 0.66 (0.53–0.78), respectively. Concerning the performance of the atrial volume ratio for differentiating post‐capillary PH, the AUC of the atrial volume ratio was significantly lower [AUC: 0.66 (95% CI, 0.53–0.78)]. The ROC analysis indicated a possible cutoff value of 27.7 mL/m² for LAVi min to predict post‐capillary PH (AUC = 0.86; sensitivity = 86%, specificity = 76%).

Conclusions

The BSA‐indexed left atrial minimum volume measured by transthoracic 3DE is a useful parameter for differentiating pre‐capillary from post‐capillary pulmonary hypertension.

The usefulness of ultrasound before induction of labor

The indications for induction of labor have been consistently on the rise. These indications are mainly medical (maternal or fetal) or social or related to convenience or maternal preferences. With the increase in the prevalence of these indications, the incidence rates of induction of labor are expected to rise continuously. This poses a substantial workload and financial burden on maternity healthcare systems. Failure rates of induction of labor are relatively high, especially when considering the maternal, fetal, and neonatal risks associated with emergency cesarean deliveries in cases of failure. Therefore, it is essential for obstetricians to carefully select women who are eligible for induction of labor, particularly those with no clinical contraindication and who have a reasonable chance of ending up with a successful noncomplicated vaginal delivery. Ultrasound has an established role in the various areas of obstetrical care. It is available, accessible, easy to perform, and acceptable to the patient. In addition, the learning curve for skillful obstetrical ultrasound scanning is rather easy to fulfill. Ultrasound has always had an important role in the assessment of maternal and fetal well-being. Indeed, it has been extensively explored as a reliable, reproducible, and objective tool in the management of labor. In this review, we aimed to provide a comprehensive update on the different applications and uses of ultrasound before induction of labor for the prediction of its success and the potential improvement of its health-related maternal and fetal outcomes.

Human Adipose-Derived Stromal/Stem Cell Culture and Analysis Methods for Adipose Tissue Modeling In Vitro: A Systematic Review

Human adipose-derived stromal/stem cells (hASC) are widely used for in vitro modeling of physiologically relevant human adipose tissue. These models are useful for the development of tissue constructs for soft tissue regeneration and 3-dimensional (3D) microphysiological systems (MPS) for drug discovery. In this systematic review, we report on the current state of hASC culture and assessment methods for adipose tissue engineering using 3D MPS. Our search efforts resulted in the identification of 184 independent records, of which 27 were determined to be most relevant to the goals of the present review. Our results demonstrate a lack of consensus on methods for hASC culture and assessment for the production of physiologically relevant in vitro models of human adipose tissue. Few studies have assessed the impact of different 3D culture conditions on hASC adipogenesis. Additionally, there has been a limited use of assays for characterizing the functionality of adipose tissue in vitro. Results from this study suggest the need for more standardized culture methods and further analysis on in vitro tissue functionality. These will be necessary to validate the utility of 3D MPS as an in vitro model to reduce, refine, and replace in vivo experiments in the drug discovery regulatory process.

The Role of 3D Exoscope Systems in Neurosurgery: An Optical Innovation

The development of the three-dimensional (3D) exoscope is a marvel of technological innovation in modern surgical practice. While its predecessor, the operating microscope (OM), has long been the gold-standard surgical visualization modality, its particular limitations in terms of accessibility and ergonomic demand have led to the development of a more sophisticated, 3D model. Specifically, the 3D exoscope allows for an enhanced image quality of the surgical field, while also being more ergonomically favorable. Moreover, this device's ability to handle delicate microsensitve procedures, along with its alleviation of surgeon fatigue, indicates great potential for neurosurgical application. For this narrative review, the authors queried PubMed database using the keyword "exoscope" to identify relevant studies involving the specialty of neurosurgery that were published in English language full text. The search yielded full-text English language-related articles regarding neurosurgical exoscope, its applications and limitations. The 3D exoscope uniquely allows for enhanced surgeon comfort and superior imaging of the patient's real-time anatomy. However, the OM was described to having a slight image favorability with fusion and decompression surgery. Cost analysis is highlighted for its potential disparity. 3D exoscopes will potentially be incorporated with intelligent carriers and robotic surgical systems. Ultimately, with further studies highlighting its use, the 3D exoscope is expected to continue to imprint its status as one of the most efficient technological visualization tools in the future of neurosurgical practice.

3-Dimensional Bioprinting of Cardiovascular Tissues: Emerging Technology

•

Advances in 3D bioprinting have tremendous potential in therapeutic development for multiple cardiovascular applications.

•

3-dimensional bioprinting is moving toward in vivo studies to evaluate printed construct functionality and safety.

•

Bioprinting techniques predominantly use extrusion-based, inkjet, and light-based printing.

•

Bioinks are composed of cells and matrix material and consist of both scaffold-based and scaffold-free inks.

Three-dimensional (3D) bioprinting may overcome challenges in tissue engineering. Unlike conventional tissue engineering approaches, 3D bioprinting has a proven ability to support vascularization of larger scale constructs and has been used for several cardiovascular applications. An overview of 3D bioprinting techniques, in vivo translation, and challenges are described.

Reliability of the modified Walch classification for advanced glenohumeral osteoarthritis using 3-dimensional computed tomography analysis: a study of the ASES B2 Glenoid Multicenter Research Group

BACKGROUND

Variations in glenoid morphology affect surgical treatment and outcome of advanced glenohumeral osteoarthritis (OA). The purpose of this study was to assess the inter- and intraobserver reliability of the modified Walch classification using 3-dimensional (3D) computed tomography (CT) imaging in a multicenter research group.

METHODS

Deidentified preoperative CTs of patients with primary glenohumeral OA undergoing anatomic or reverse total shoulder arthroplasty (TSA) were reviewed with 3D imaging software by 23 experienced shoulder surgeons across 19 institutions. CTs were separated into 2 groups for review: group 1 (96 cases involving all modified Walch classification categories evaluated by 12 readers) and group 2 (98 cases involving posterior glenoid deformity categories [B2, B3, C1, C2] evaluated by 11 readers other than the first 12). Each case group was reviewed by the same set of readers 4 different times (with and without the glenoid vault model present), blindly and in random order. Inter- and intraobserver reliabilities were calculated to assess agreement (slight, fair, moderate, substantial, almost perfect) within groups and by modified Walch classification categories.

RESULTS

Interobserver reliability showed fair to moderate agreement for both groups. Group 1 had a kappa of 0.43 (95% confidence interval [CI]: 0.38, 0.48) with the glenoid vault model absent and 0.41 (95% CI: 0.37, 0.46) with it present. Group 2 had a kappa of 0.38 (95% CI: 0.33, 0.43) with the glenoid vault model absent and 0.37 (95% CI: 0.32, 0.43) with it present. Intraobserver reliability showed substantial agreement for group 1 with (0.63, range 0.47-0.71) and without (0.61, range 0.52-0.69) the glenoid vault model present. For group 2, intraobserver reliability showed moderate agreement with the glenoid vault model absent (0.51, range 0.30-0.72), which improved to substantial agreement with the glenoid vault model present (0.61, range 0.34-0.87).

DISCUSSION

Inter- and intraobserver reliability of the modified Walch classification were fair to moderate and moderate to substantial, respectively, using standardized 3D CT imaging analysis in a large multicenter study. The findings potentially suggest that cases with a spectrum of posterior glenoid bone loss and/or dysplasia can be harder to distinguish by modified Walch type because of a lack of defined thresholds, and the glenoid vault model may be beneficial in determining Walch type in certain scenarios. The ability to reproducibly separate patients into groups based on preoperative pathology, including Walch type, is important for future studies to accurately evaluate postoperative outcomes in TSA patient cohorts.

3-Dimensional Transseptal Puncture Based on Electrographic Characteristics of Fossa Ovalis: A Fluoroscopy-Free and Echocardiography-Free Method

OBJECTIVES

This study sought to define electrographic characteristics of the fossa ovalis (FO) and use these findings in developing a 3-dimensional (3D) transseptal puncture (TSP) technique that does not rely on fluoroscopy or echocardiography.

BACKGROUND

Traditional TSP method based on fluoroscopy or echocardiography is basically a 2-dimensional (2D) technique. A valid 3D method of TSP has not been sufficiently clarified.

METHODS

The shape of the FO and its center were "electrographically" defined by comparing their potential characteristics to those of the surrounding limbus. After validation by intracardiac echocardiography, this FO mapping was incorporated into 3D electroanatomical reconstruction of the right atrium. Using a new catheter connection, the transseptal needle could be visualized nonfluoroscopically and directed to the precise localization of the FO on the electroanatomic map.

RESULTS

A total of 276 patients who underwent atrial fibrillation ablation were included. The central FO was identified in all cases with atrial electrogram voltage at 0.33 ± 0.21 mV. The amplitude of atrial potential at the FO annulus was 1.70 ± 0.72 mV (p < 0.001). By incorporating the electrographically defined FO into the 3D electroanatomic mapping and using the transseptal needle visualization approach, TSP was successful in all patients, with 91% of the cases at the first attempt. Atrial fibrillation ablation was completed in all patients with no major complication.

CONCLUSIONS

Electrographic characteristics of the FO center are distinct from those of the surrounding regions. This information can be leveraged to define the FO on 3D electroanatomic mappings, thereby facilitating safe TSP without the need of ancillary imaging with fluoroscopy or echocardiography.

Clinical application of 3D-VOG analysis for quantitative evaluation of Otolith-Ocular reflex in the roll and pitch planes

BACKGROUND

Management of vestibular falls requires precise evaluation of otolithic function and gravity recognition. Tilt of the head in the roll plane causes ocular counter rolling (OCR) with a gain of 5-10%, which can be a quantitative parameter related to the otolith-ocular reflex (OOR) in that plane. However, the OOR in the pitch plane is indiscernible because of our ability to voluntarily gaze and pursue. 3 D eye movements and its Listing's plane description can provide novel parameters with which to evaluate OOR, even in the pitch plane.

OBJECTIVES

To evaluate the utility of 3 D eye movement analysis in video oculography (VOG) as a quantitative parameter reflecting otolithic function during head movements associated with daily life.

MATERIALS AND METHODS

In healthy subjects, we analyzed the changes in 3 D eye movements and the Listing's plane that occur with static gravitational modification.

RESULTS

OOR during head tilt in the roll plane revealed that OCR amplitude had a saturating/peaked conformation and was not fitted by a sine curve. OOR in the pitch plane revealed anteroposterior leaning of the Listing's plane.

CONCLUSIONS

These novel tools for minimally invasive evaluation of OOR in a clinical setting could potentially enable us to quantitatively evaluate peripheral static disequilibrium.

Assessment of D-Shaped Annulus of Mitral Valve in Patients with Severe MR Using Semi-Automated 4-Dimensional Analysis: Implications for Transcatheter Interventions

The development of transcatheter mitral valve replacement therapies requires accurate post-processing analysis tools to provide D-shaped mitral annulus dimensions from 3-dimensional (3D) data. The agreement between two semi-automated, software packages to process 3D transesophageal echocardiography (TEE) data for the measurement of the mitral valve annulus dimensions was evaluated. 3DTEE data of patients with moderate-severe mitral regurgitation (MR) were postprocessed with semi-automated, vendor-independent (VI) software and vendor-specific (VS) software. Both post-processing software provided key measurements for the selection of transcatheter valve prosthesis size: annulus area, annulus circumference and the septal-to-lateral distance of the annulus. The intertrigonal distance was provided only by the VS software. The inter- and intra-observer agreements were assessed with Bland-Altman analysis. Of 105 patients (63.8 ± 11 years, 66% male) with MR, 28 had secondary MR, 45 fibroelastic deficiency, and 32 Barlow's disease. Using VS software, the dimensions for the overall population were 16.1 ± 4.6 cm² for annulus area, for circumference 14.4 ± 1.9 cm, intertrigonal distance 3.4 ± 0.5 cm and septal-to-lateral distance 3.8 ± 0.6 cm. Similar dimensions were obtained using VI software: 15.7 ± 4.6 cm² for annulus area, 14.5 ± 2.0 cm for circumference, and 4.1 ± 0.6 cm for septal-to-lateral distance. The inter- and intra-observer agreement for both software programs was excellent. In conclusion, current post-processing software programs for 3DTEE data of the mitral valve annulus provide good reproducibility of key measurements to select the transcatheter prosthesis size.

Combined 3-dimensional printing model and 3-dimensional fluoroscopic navigation to assist C2 pedicle screw insertion: A case report

RATIONALE

The misplaced cervical screw can cause catastrophic surgical complications, such as nerve root damage, vertebral artery compromise, spinal cord injury, and even paraplegia. Thus, the present study aims to describe a novel technique of 3-dimensional printing model (3DPM) combined with 3-dimensional fluoroscopic navigation (3DFN) to facilitate C2 pedicle screw insertion.

PATIENT CONCERNS

A 56-year-old male patient presented hypoesthesia of the trunk and extremities, accompanied by a walking disorder.

DIAGNOSES

Congenital atlantoaxial malformation with atlantoaxial dislocation.

INTERVENTIONS

He underwent an occipital cervical fusion. We used 3DPM and 3DFN technology to guide C2 pedicle screws insertion.

OUTCOMES

We inserted 2 pedicle screws and 4 lateral mass screws using the combined 3DPM and 3DFN technology. All screws were classified as excellent position postoperatively. The surgical duration, total fluoroscopic time, and the bleeding volume were 258 minutes, 3.9 minutes, and 237 mL, respectively. No surgical complications, such as neurological compromise, nonunion, dysphagia, infection, polypnea, fixation failure, pseudarthrosis formation, or revision surgery, were observed. The follow-up duration lasted 30 months.

LESSONS

The combination of 3DPM and 3DFN to promote C2 pedicle screws implantation is a safe, accurate, reliable, and useful technology, which can achieve an excellent therapeutic effect and avoid surgical complications. However, using the 3DPM and 3DFN technology may increase the financial burden of patients.

Three-Dimensional In Vitro Staphylococcus aureus Abscess Communities Display Antibiotic Tolerance and Protection from Neutrophil Clearance

Staphylococcus aureus is a prominent human pathogen in bone and soft-tissue infections. Pathophysiology involves abscess formation, which consists of central staphylococcal abscess communities (SACs), surrounded by a fibrin pseudocapsule and infiltrating immune cells. Protection against the ingress of immune cells such as neutrophils, or tolerance to antibiotics, remains largely unknown for SACs and is limited by the lack of availability of in vitro models. We describe a three-dimensional in vitro model of SACs grown in a human plasma-supplemented collagen gel. The in vitro SACs reached their maximum size by 24 h and elaborated a fibrin pseudocapsule, as confirmed by electron and immunofluorescence microscopy. The in vitro SACs tolerated 100× the MIC of gentamicin alone and in combination with rifampin, while planktonic controls and mechanically dispersed SACs were efficiently killed. To simulate a host response, SACs were exposed to differentiated PLB-985 neutrophil-like (dPLB) cells and to primary human neutrophils at an early stage of SAC formation or after maturation at 24 h. Both cell types were unable to clear mature in vitro SACs, but dPLB cells prevented SAC growth upon early exposure before pseudocapsule maturation. Neutrophil exposure after plasmin pretreatment of the SACs resulted in a significant decrease in the number of bacteria within the SACs. The in vitro SAC model mimics key in vivo features, offers a new tool to study host-pathogen interactions and drug efficacy assessment, and has revealed the functionality of the S. aureus pseudocapsule in protecting the bacteria from host phagocytic responses and antibiotics.

Novel 3D printed integral customized acetabular prosthesis for anatomical rotation center restoration in hip arthroplasty for developmental dysplasia of the hip crowe type III: A Case Report

RATIONALE

Exact restoration of the rotation center in total hip arthroplasty (THA) is technically challenging in patients with end-stage osteoarthritis due to developmental dysplasia of the hip (DDH), especially in the Crowe type II and III procedures. The technical difficulty is attributable to the complex acetabular changes. In this study, a novel 3-dimensional (3D) printed integral customized acetabular prosthesis for anatomical rotation restoration in THA for DDH Crowe type III was developed using patient-specific Computer-aided design and additive manufacturing (AM) methods.

PATIENT CONCERNS

A 69-year-old female patient had developed left hip joint pain and restricted movement for 40 years; the symptoms had increased in the past 5 months. Pain, limited motion of the left hip joint, and lower limb length discrepancy were noted during physical examination.

DIAGNOSIS

The patient was diagnosed with left hip end-stage osteoarthritis secondary to DDH (Crowe type III).

INTERVENTION

A 3D printed acetabulum model was manufactured and a simulated operation was performed to improve the accuracy of reconstruction of the rotation center and bone defect. A 3D printed titanium alloy integral customized acetabular prosthesis was designed according to the result of simulated operation. The integral customized prothesis was implanted subsequently via the posterolateral approach. Radiography of the pelvis and Harris score assessment were performed during the perioperative period as well as at the 6- and 12-month follow-up.

OUTCOMES

The 3D printed integral customized acetabular prosthesis matched precisely with the reamed acetabulum. The rotation center was restored and the bone defect was exactly reconstructed. There were no signs of prosthetic loosening at the 12-month follow-up. The Harris score gradually improved during the follow-up period.

LESSONS

Satisfactory results of hip rotation restoration and bone defect reconstruction could be achieved by using 3D printed integral customized acetabular prosthesis, which provides a promising way to reconstruct the acetabulum in patients with DDH anatomically and rapidly for THA.

Three-Dimensional Versus Radiographic Measurements for Analyzing Extra-Articular Distal Radius Malunion

PURPOSE

To compare the accuracy of evaluating deformity in distal radius malunions using plain radiographic measurements compared with a 3-dimensional method involving 3-dimensional computer bone models.

METHODS

Consecutive patients who had an extra-articular distal radius malunion were included. Standard radiographs and computed tomography scans of both wrists were performed. Palmar tilt, radial tilt, and ulnar variance were measured on radiographs. The computed tomography scan data were sent to a workstation and 3-dimensional bone surface models of the radius were created. The 3-dimensional palmar tilt, 3-dimensional radial tilt, 3-dimensional ulnar variance, and axial rotational deformity were calculated.

RESULTS

Thirteen patients, mean age 40 years (range, 22-57 years) were included. The 3 3-dimensional values were positively correlated with their corresponding radiographic values. Nevertheless, the 3-dimesional palmar tilt and 3-dimensional radial tilt values were slightly smaller than the radiographic palmar tilt and radial tilt. The quantitative difference between the 3-dimensional method and plain radiographs was on average 2° for the dorsal deformity group and 3° for the palmar deformity group. The 3-dimensional ulnar variance was significantly higher than the radiographic ulnar variance by an average of +1.3 mm for malunions with dorsal tilt and +0.6 mm for malunions with palmar tilt. The 3-dimensional method allowed us to measure the extent of the axial rotational deformity, which was 9° on average (range, 2° to 21°).

CONCLUSIONS

Despite small differences, measurements made on both plain radiographs and 3-dimensional computer bone models are accurate for evaluating the deformity in extra-articular distal radius malunions. Our 3-dimensional method seems to provide a more accurate measurement of ulnar variance, particularly for dorsally angulated cases, and is helpful for measuring rotational malalignment.

CLINICAL RELEVANCE

In this study, we found that either a 3-dimensional computer bone model or plain radiographs can be used as a benchmark to evaluate the deformity of extra-articular distal radius malunion. The 3-dimensional method can also be used to define axial rotational deformity.

Radiation exposure of a mobile 3D C-arm with large flat-panel detector for intraoperative imaging and navigation - an experimental study using an anthropomorphic Alderson phantom

Background

Intraoperative 3-dimensional (3D) navigation is increasingly being used for pedicle screw placement. For this purpose, dedicated mobile 3D C-arms are capable of providing intraoperative fluoroscopy-based 3D image data sets. Modern 3D C-arms have a large field of view, which suggests a higher radiation exposure. In this experimental study we therefore investigate the radiation exposure of a new mobile 3D C-arm with large flat-panel detector to a previously reported device with regular flat-panel detector on an Alderson phantom.

Methods

We measured the radiation exposure of the Vision RFD 3D (large 30 × 30 cm detector) while creating 3D image sets as well as standard fluoroscopic images of the cervical and lumbar spine using an Alderson phantom. The dosemeter readings were then compared with the radiation exposure of the previous model Vision FD Vario 3D (smaller 20 × 20 cm detector), which had been examined identically in advance and published elsewhere.

Results

The larger 3D C-arm induced lower radiation exposures at all dosemeter sites in cervical 3D scans as well as at the sites of eye lenses and thyroid gland in lumbar 3D scans. At ​​male and especially female gonads in lumbar 3D scans, however, the larger 3D C-arm showed higher radiation exposures compared with the smaller 3D C-arm. In lumbar fluoroscopic images, the dosemeters near/in the radiation field measured a higher radiation exposure using the larger 3D C-arm.

Conclusions

The larger 3D C-arm offers the possibility to reduce radiation exposures for specific applications despite its larger flat-panel detector with a larger field of view. However, due to the considerably higher radiation exposure of the larger 3D C-arm during lumbar 3D scans, the smaller 3D C-arm is to be recommended for short-distance instrumentations (mono- and bilevel) from a radiation protection point of view. The larger 3D C-arm with its enlarged 3D image set might be used for long instrumentations of the lumbar spine. From a radiation protection perspective, the use of the respective 3D C-arm should be based on the presented data and the respective application.

Evaluation of the relationship between malar projection and lower facial convexity in terms of perceived attractiveness in 3-dimensional reconstructed images

Background

This study aimed to investigate dental student’s perception of facial attractiveness with regard to different combinations of anteroposterior malar-jaw positions using 3-dimensional (3-D) reconstructed images of subjects.

Methods

Two Chinese young adults (1 male and 1 female) with straight profiles and average malar projections were selected for the study. 3-D facial images and cone-beam computed tomography images of these two subjects were superimposed using 3-D imaging software. Lateral and oblique views of nine different images were created by moving the maxillomandibular complex and/or zygomatic bone by 4 mm either forward or backward along the sagittal plane. One hundred three undergraduate dental students (n = 24, 33, and 46 students from the Year 3, 4, and 5, respectively) then scored lateral and 45° oblique view images of the newly reconstructed faces.

Results

In the present study, images with a neutral malar and retruded jaws were found to be the most attractive in both male and female subjects. In addition, the Protruded malar (PM) group (p < 0.001), and the Retruded Jaws (RJ) group were rated more attractive (p < 0.001). Furthermore, the Relatively Prominent malar (RP) group was rated more attractive (p < 0.001) when malar-jaw relative positions were compared.

Conclusion

This study shows that a neutral or a protruded malar favours facial attractiveness in both Chinese male and female subjects. Therefore, an appropriate relationship between malar projection and lower facial convexity should be taken into consideration while designing the orthodontic/orthognathic treatment plans for enhanced aesthetic outcomes.

The Diagnostic Value of 3D Power Doppler Ultrasound Combined With VOCAL in the Vascular Distribution of Breast Masses

RATIONALE AND OBJECTIVES

This study uses a three-dimensional energy Doppler technique combined with the Virtual Organ Computer-aided Analysis (VOCAL) method in order to determine the diagnostic threshold of blood flow index in breast tumors to provide a reference for evaluation and treatment options.

MATERIALS AND METHODS

We collected 322 solid lesions which had been operated. Each lesion met the definite pathological diagnosis; collected lesions included 262 cases of benign lesions and 60 cases of malignant lesions. All examinations were performed by using GE LOGIQ E9 with VOCAL software. Volume and four distinct vascular indices of gray mean (MG), power mean, ratio (R), and vascular flow index (VFI) were calculated by using the VOCAL software. Sampling and calculation were repeated three times and the mean value was calculated.

RESULTS

The average age and power of the malignant group were greater than those of the benign group, ie p < .01 which had significant differences. The gray mean of the malignant group was lower than that of the benign group, ie p > .05 which had no significant differences between benign and malignant groups. The ratio, vascular flow index and volume had significant differences, i.e. p < .01. The area under the receiver operating characteristic curve (AUC) were 0.864, 0.830, 0.800, 0.758, and 0.764 for age, power, ratio, vascular flow index, and volume, respectively. The research indicators were higher than 50% of the curve showing their diagnostic value. The cut-off points of age, power, ratio, vascular flow index, and volume were 37.5, 26.56, 0.031, 0.846, and 1.75, respectively. Their corresponding sensitivity were 93.3%, 75%, 81.7%, 68.3%, 63.3%, and the specificity were 68.7%, 81%, 70.2%, 75.6%, and 81.7%, respectively. Comparison of vascular indices combined with the Breast imaging reporting and data System (BI-RADS) score and simple BI-RADS method, the AUC of power + BI-RADS, ratio + BI-RADS, VFI + BI-RADS, and BI-RADS alone are 0.928, 0.903, 0.895, and 0.796, respectively, which were higher than 50% of the curve. Sensitivity was 81.7%, 80%, 88.3%, 86.7%, and specificity was 88.5%, 85.5%, 77.1%, 69.5%, respectively. The power + BI-RADS method has the highest AUC among these three methods.

CONCLUSIONS

Quantitative measurement of blood flow and blood vessel distribution in breast tumors by three-dimensional power Doppler ultrasound combined with the VOCAL method is more accurate and sensitive than the traditional two-dimensional ultrasound. And this method has potential promising applications in many current active research areas, such as the studies of random distribution of intratumoral blood vessels or the normalization of tumor blood vessels. Three-dimensional power Doppler ultrasound combined with the VOCAL method provides a new approach to achieving accurate judgments and the method evaluates the curative effect in breast cancer patients.

Three-dimensional vs 2-dimensional laparoscopic gastrectomy for gastric cancer: A systematic review and meta-analysis

BACKGROUND

Both 3-dimensional (3D) laparoscopic gastrectomy (LG) and 2-dimensional (2D) LG are commonly used for gastric cancer (GC). To investigate their safety and efficacy, we performed this meta-analysis.

METHODS

PubMed, The Cochrane Library, Science Direct, Embase, Scopus, and Web of Science were systematically searched to identify relevant studies. The total number of lymph node dissections (LNDs), operation time, blood loss, postoperative hospital stay, postoperative complications, and hospitalization cost were extracted as major endpoints.

RESULTS

Among 904 articles that were enrolled, 9 studies were included for analysis. The 3D group was observed to have shorter operation times [95% confidence interval (CI): -0.54 to -0.06; P = .01] and less blood loss (95% CI: -0.41 to -0.19; P < .00001) than the 2D group. Compared with the 2D group, slightly higher hospitalization cost was found in the 3D group (95% CI: 0.06-0.37; P = .008). However, the outcomes among the total LNDs, postoperative hospital stay, and postoperative complications were similar. Subgroup analysis suggested that the 3D LG group had more 11p (2.22 ± 1.80 vs 1.47 ± 1.99, P = .019) and 8a (2.52 ± 1.88 vs 1.48 ± 1.43, P = .001) LNDs compared to the 2D LG group.

CONCLUSIONS

3D LG has advantages for GC, with shorter operation times, less blood loss, and possibly more LNDs. However, the cost was slightly higher than that of 2D LG.

Accuracy of patient-specific instrumentation in shoulder arthroplasty: a systematic review and meta-analysis

Background

There has been significant recent emphasis on the use of patient-specific instrumentation (PSI) in shoulder arthroplasty. However, clinical data are lacking to support the increased time and expense associated with PSI. Our purposes were to determine whether PSI significantly improves implantation accuracy during total shoulder arthroplasty (TSA) and to analyze available techniques and correlation with clinical outcomes. We hypothesized that PSI may improve glenoid component position radiographically but without correlation with clinical outcomes.

Methods

The MEDLINE, Scopus, Embase, and Cochrane Library databases were queried. Included articles reported use of any preoperative or intraoperative PSI techniques, models, or guides to assist with TSA prosthesis implantation. The primary outcomes were mean deviation from the preoperative plan in version (in degrees), inclination (in degrees), and entry-point offset on the glenoid (in millimeters).

Results

Among the included articles, 518 TSA procedures (352 anatomic and 166 reverse) were performed. The mean postoperative errors in both version and inclination angles were 5° or less in 20 articles (90.9%) using PSI. Meta-analysis revealed no statistically significant differences in version error (P > .999, I ² = 64.6%), inclination error (P = .702, I ² = 82.2%), or positional offset (P = .777, I ² = 85.7%) between PSI and standard instrumentation. No data regarding patient-reported outcome measures, range of motion, strength, or glenoid component loosening and longevity were reported.

Conclusions

Meta-analysis revealed no significant differences in accuracy between PSI and standard instrumentation. Although PSI may possess the potential to improve TSA techniques, further investigations regarding long-term clinical outcomes, impact on operating room time, and cost-effectiveness are warranted before PSI can be routinely recommended over conventional instrumentation.

Is the Glasses-Free 3-Dimensional Display System More Effective for Complex Video-Assisted Thoracic Surgery? A Self-Controlled Study Ex Vivo

Objective. Considering the demerits of a high-definition 2-dimensional (HD-2D) system, with its lack of stereopsis, and a conventional 3-dimensional (C-3D) system, which results in a dimmed image, we have recently developed a glasses-free 3-dimensional (GF-3D) display system for reconstruction surgeries such as video-assisted thoracic surgery (VATS) for tracheal reconstruction. Methods. Thoracic surgeons were invited to complete thoracoscopic continuous suture of a transected porcine trachea using the HD-2D, C-3D, and GF-3D systems on separate mornings in randomized order. The duration, numbers of stitches, and distance between every 2 stitches were recorded for every procedure. The surgeons' spontaneous eye blink rate was recorded for 5 minutes before the procedure and the last 5 minutes of the procedure. Results. Fifteen volunteers successfully completed the tracheal reconstruction procedures in this study. Both C-3D (0.403 ± 0.064 stitch/min, P < .001) and GF-3D (0.427 ± 0.079 stitch/min, P < .001) showed significant advantages in speed compared with HD-2D (0.289 ± 0.065 stitch/min). Both C-3D (2.536 ± 2.223 mm, P < .001) and GF-3D (2.603 ± 2.159 mm, P < .001) showed significant advantages in accuracy compared with HD-2D (3.473 ± 3.403 mm). Both HD-2D (1.240 ± 0.642, P < .001) and GF-3D (1.307 ± 0.894, P < .001) showed significant advantages in eye fatigue compared with C-3D (3.333 ± 1.44). Conclusions. All 3 available display systems are efficient for complex VATS. With the help of stereopsis, surgeons can achieve faster operation using C-3D and GF-3D systems in a thoracoscopic simulated setting. GF-3D may be a more effective display system for VATS reconstruction in terms of speed, accuracy, and eye fatigue during operations.

Three-dimensional computed tomography modeling for kinematic analysis of double-strand lateral ulnar collateral ligament reconstruction

BACKGROUND

When treating posterolateral rotatory instability, the lateral ulnar collateral ligament (LUCL) is more commonly reconstructed than the other dynamic stabilizer structures. Although numerous surgical techniques have been described for LUCL reconstruction, studies have been limited to static analyses of single-strand reconstructions. The aim of this study was to dynamically analyze the kinematics of double-strand LUCL reconstructions with 3 different configurations of graft placement: horizontal, vertical, and triangular.

METHODS

Five healthy elbow joints with no signs of pre-existing pathology were scanned by computed tomography, and the images were converted into 3-dimensional models. The humeral origin and ulnar insertions of the 2 ligament strands were registered in 3-matic software for the 3 graft placement configurations. A dynamic elbow joint was simulated at 1° increments throughout the motion arc. The ligament strand lengths and the difference between them were measured.

RESULTS

The ligament lengths for each strand for the 3 graft configurations were as follows: horizontal, 31.0 ± 4.6 mm and 34.3 ± 5.0 mm; vertical, 32.5 ± 3.6 mm and 35.4 ± 4.2 mm; and triangular, 32.0 ± 4.0 mm and 33.7 ± 3.1 mm. The minimum length differences for the graft strands through the motion arc for the horizontal, vertical, and triangular graft configurations were 1.1, 0.0, and 1.0 mm, respectively.

CONCLUSIONS

Dynamic analyses using a 3-dimensional elbow model showed that none of the configurations for double-strand LUCL reconstruction were isometric. However, the vertical double-strand configuration was nearly isometric and may therefore serve as a coequal option.

Evaluation of preferred lip position according to different tip rotations of the nose in class I young adult subjects

INTRODUCTION

The mouth plays an important role in the overall aesthetic appearance of the face. The aims of this study were to determine the optimal antero-posterior (AP) lip position relative to various rotations of the nasal tip and assess the impact of the nasolabial angle on facial aesthetics.

MATERIAL AND METHODS

Three-dimensional facial volumes, in motion, of one Caucasian male and one Caucasian female with a Class I malocclusion and an orthognathic profile were modified to alter the nasal tip rotation (3 rotations) and the AP lips position (6 positions). 72 generated models were created in two and three-dimensions. Generated models were rated online by 60 dentists, 60 orthodontists and 60 laypeople, using a Visual Analogue Scale. Scores were analysed according to lip position, rater's profession and gender.

RESULTS

General agreement was found between all groups on the most and least preferred lip positions. No differences between male and female raters were found. All raters were more influenced by the 3-dimensional rotating facial volume than by 2-dimensional angles. Similar angular values for the nasolabial angles were found in the most and least preferred profiles, showing that the most influential factor in facial aesthetics was the lip position, and stressing the need to evaluate each component of the nasolabial angle independently.

CONCLUSION

The lip position was the determinant factor in facial aesthetics with little influence of the nose tip rotation. Three-dimensional evaluation of the nose and lip were needed to establish a soft tissue-based treatment plan.

Autophagy facilitates the release of immunogenic signals following chemotherapy in 3D models of mesothelioma

We have previously shown that nearly half of mesothelioma patients have tumors with low autophagy and that these patients have a significantly worse outcome than those with high autophagy. We hypothesized that autophagy may be beneficial by facilitating immunogenic cell death (ICD) of tumor cells following chemotherapy. An important hallmark of ICD is that death of tumor cells is preceded or accompanied by the release of damage-associated molecular pattern molecules (DAMPs), which then can stimulate an antitumor immune response. Therefore, we measured how autophagy affected the release of three major DAMPs: high mobility group box 1 (HMGB1), ATP, and calreticulin following chemotherapy. We found that autophagy in three-dimensional (3D) models with low autophagy at baseline could be upregulated with the cell-permeant Tat-BECN1 peptide and confirmed that autophagy in 3D models with high autophagy at baseline could be inhibited with MRT 68921 or ATG7 RNAi, as we have previously shown. In in vitro 3D spheroids, we found that, when autophagy was high or upregulated, DAMPs were released following chemotherapy; however, when autophagy was low or inhibited, DAMPs release was significantly impaired. Similarly, in ex vivo tumors, when autophagy was high or upregulated, HMGB1 was released following chemotherapy but, when autophagy was low, HMGB1 release was not seen. We conclude that autophagy can be upregulated in at least some tumors with low autophagy and that upregulation of autophagy can restore the release of DAMPs following chemotherapy. Autophagy may be necessary for ICD in this tumor.