Axial rotation analysis in total ankle arthroplasty using weight-bearing computer tomography and three-dimensional modeling.

BACKGROUND: Post-operative alignment is the most critical indicator for a successful total ankle arthroplasty (TAA). Total ankle malrotation is associated with an increased risk for polyethylene wear and medial gutter pain. Currently, there is no consensus on the correct way to measure the alignment of the tibial and talar component rotations in the axial plane. In the current study, the post-operative analysis system was assessed using weight-bearing computer tomography and a three-dimensional (3D) model. The purpose of the study was to assess the inter-observer and intra-observer agreement of this system. MATERIAL AND METHOD: Four angles were measured by two raters independently in two separate readings: posterior tibial component rotation angle (PTIRA), posterior talar component rotation angle (PTARA), tibia talar component axial angle (TTAM), and tibial component to the second metatarsal angle (TMRA). Agreement analysis was quantified according to the interclass coefficient. RESULTS: Sixty TAAs across 60 patients were evaluated. A good inter-observer agreement and intra-observer agreement when measuring the PTIRA, PTARA, and TTAM angles was observed along with an excellent inter-observer agreement and intra-observer agreement when measuring the TMRA angle. CONCLUSION: In conclusion, the current 3D model-based measurement system demonstrates good to excellent inter and intra-agreement. According to these results, 3D modelling can be reliably used to measure and assess the axial rotation of TAA components. LEVEL OF EVIDENCE: Level 3 retrospective study.

Endothelial Cells as Tools to Model Tissue Microenvironment in Hypoxia-Dependent Pathologies.

Endothelial cells (ECs) lining the blood vessels are important players in many biological phenomena but are crucial in hypoxia-dependent diseases where their deregulation contributes to pathology. On the other hand, processes mediated by ECs, such as angiogenesis, vessel permeability, interactions with cells and factors circulating in the blood, maintain homeostasis of the organism. Understanding the diversity and heterogeneity of ECs in different tissues and during various biological processes is crucial in biomedical research to properly develop our knowledge on many diseases, including cancer. Here, we review the most important aspects related to ECs' heterogeneity and list the available in vitro tools to study different angiogenesis-related pathologies. We focus on the relationship between functions of ECs and their organo-specificity but also point to how the microenvironment, mainly hypoxia, shapes their activity. We believe that taking into account the specific features of ECs that are relevant to the object of the study (organ or disease state), especially in a simplified in vitro setting, is important to truly depict the biology of endothelium and its consequences. This is possible in many instances with the use of proper in vitro tools as alternative methods to animal testing.

Bioengineered Cystinotic Kidney Tubules Recapitulate a Nephropathic Phenotype.

Nephropathic cystinosis is a rare and severe disease caused by disruptions in the CTNS gene. Cystinosis is characterized by lysosomal cystine accumulation, vesicle trafficking impairment, oxidative stress, and apoptosis. Additionally, cystinotic patients exhibit weakening and leakage of the proximal tubular segment of the nephrons, leading to renal Fanconi syndrome and kidney failure early in life. Current in vitro cystinotic models cannot recapitulate all clinical features of the disease which limits their translational value. Therefore, the development of novel, complex in vitro models that better mimic the disease and exhibit characteristics not compatible with 2-dimensional cell culture is of crucial importance for novel therapies development. In this study, we developed a 3-dimensional bioengineered model of nephropathic cystinosis by culturing conditionally immortalized proximal tubule epithelial cells (ciPTECs) on hollow fiber membranes (HFM). Cystinotic kidney tubules showed lysosomal cystine accumulation, increased autophagy and vesicle trafficking deterioration, the impairment of several metabolic pathways, and the disruption of the epithelial monolayer tightness as compared to control kidney tubules. In particular, the loss of monolayer organization and leakage could be mimicked with the use of the cystinotic kidney tubules, which has not been possible before, using the standard 2-dimensional cell culture. Overall, bioengineered cystinotic kidney tubules recapitulate better the nephropathic phenotype at a molecular, structural, and functional proximal tubule level compared to 2-dimensional cell cultures.

Compendious survey of protein tandem repeats in inbred mouse strains.

Short tandem repeats (STRs) play a crucial role in genetic diseases. However, classic disease models such as inbred mice lack such genome wide data in public domain. The examination of STR alleles present in the protein coding regions (are known as protein tandem repeats or PTR) can provide additional functional layer of phenotype regulars. Motivated with this, we analysed the whole genome sequencing data from 71 different mouse strains and identified STR alleles present within the coding regions of 562 genes. Taking advantage of recently formulated protein models, we also showed that the presence of these alleles within protein 3-dimensional space, could impact the protein folding. Overall, we identified novel alleles from a large number of mouse strains and demonstrated that these alleles are of interest considering protein structure integrity and functionality within the mouse genomes. We conclude that PTR alleles have potential to influence protein functions through impacting protein structural folding and integrity.

Automated Identification from Dental Data (AutoIDD): A new development in digital forensics.

There has been a significant expansion in the use of 3-dimensional (3D) dental images in recent years. In the field of forensic odontology, an automated 3D dental identification system could enhance the identification process. This study presents a novel method for automated human dental identification using 3D digital dental data by utilising a dental identification scenario. The total study sample was divided into two groups: Group A (120 dental models) and Group B (120 Intra-oral scans-IOS). Group A data was composed of 3D scanned dental models of post-orthodontic treated patients (30 maxillary and 30 mandibular). This data was considered as AM digital data. To generate an identical sample, the dental casts (60) of the same patients were retrieved and laser scanned. These models were considered as PM digital data. Group B data (IOS) was obtained from 30 study participants. To reconstruct a dental identification scenario 30 maxillary and 30 mandibular IOS were obtained from 30 participants and were considered as IOS-AM. After one year, another set of IOS (60) were acquired from the same participants and were considered as IOS-PM. The results showed that the AutoIDD (Automated Identification from Dental Data) software was consistent in accuracy; capable of differentiating "correct matches" (high match percentage) from "non-matches" (very low percentage) by 3D image superimposition. The match percentage of the maxillary and mandibular IOS ranged from 64 to 100% and 81-100 %, with a mean distance (mm) of 0.094 and 0.093 respectively. This study demonstrated the feasibility of using 3D scans through a new automated software - AutoIDD in digital forensics to assist the forensic expert in confirming the identity of a deceased individual from the available AM dental records.

Patient-Specific 3-Dimensional Modeling and Its Use for Preoperative Counseling of Patients Undergoing Hip Arthroscopy.

BACKGROUND: Femoroacetabular impingement (FAI) represents complex alterations in the bony morphology of the proximal femur and acetabulum. Imaging studies have become crucial in diagnosis and treatment planning for symptomatic FAI but also have limited patient understanding and satisfaction. Exploration of alternative patient counseling modalities holds promise for improved patient understanding, satisfaction, and ultimately for outcomes. PURPOSE: To compare perceived understanding of functional anatomy and FAI pathomorphology among patients counseled with routine computed tomography (CT), generic hip models, and a 3-dimensional (3D) model printed in accordance with a patient's specific anatomy. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A prospective randomized analysis of patients presenting with radiographically confirmed FAI was conducted between November 2015 and April 2017. Patients were randomized into groups that received preoperative counseling with CT imaging alone, a generic human hip model, or a haptic 3D model of their hip. All groups were subjected to a novel questionnaire examining patient satisfaction and understanding on a variety of topics related to FAI. Data were compared with bivariate and multivariate analyses. Statistical significance was determined as P < .05. RESULTS: Thirty-one patients were included in this study (25 men, 6 women). Ten patients were randomized to the CT-only group, 11 to the generic hip model group, and 10 to receive custom 3D-printed models of their hips. Patients preoperatively counseled with isolated CT imaging or a generic hip model reported greater understanding of their pathophysiology and the role of surgical intervention when compared with those counseled with haptic 3D models (P = .03). At final follow-up, patients counseled with the use of isolated CT imaging or haptic 3D models reported greater increases and retention of understanding as compared with those counseled with generic hip models alone (P = .03). CONCLUSION: Preoperative counseling with haptic 3D hip models does not appear to favorably affect patient-reported understanding or satisfaction with regard to FAI when compared with the use of CT imaging alone. Continued research into alternative counseling means may serve to further improve patient understanding and satisfaction on this complex anatomic phenomenon.