Anatomical Design Research Articles

Design and optimization of a novel patient-specific subperiosteal implant additively manufactured in yttria-stabilized zirconia

ObjectiveTo design a patient-specific subperiosteal implant for a severely atrophic maxillary ridge using yttria-stabilized additively manufactured zirconia (3YSZ) and evaluate its material properties by applying topology optimization (TO) to replace bulk material with a lattice structure. MaterialsA contrast-based segmented skull model from anonymized computed tomography data of a patient was used for the initial anatomical design of the implant for the atrophic maxillary ridge. The implant underwent finite element analysis (FEA) and TO under different occlusal load-bearing conditions. The resulting implant designs, in bulk material and lattice, were evaluated via in-silico tensile tests and 3D printed. ResultsThe workflow produced two patient-specific subperiosteal designs: a) an anatomically precise bulk implant, b) a TO lattice implant. In-silico tensile tests revealed that the Young’s modulus of yttria-stabilized zirconia is 205 GPa for the bulk material and 83.3 GPa for the lattice. Maximum principal stresses in the implant were 61.14 MPa in bulk material and 278.63 MPa in lattice, both tolerable, indicating the redesigned implant can withstand occlusal forces of 125–250 N per abutment. Furthermore, TO achieved a 13.10 % mass reduction and 208.71 % increased surface area, suggesting improved osteointegration potential. SignificanceThe study demonstrates the planning and optimization of ceramic implant topology. A further iteration of the implant was successfully implanted in a patient-named use case, employing the same fabrication process and parameters.

Validity of ChatGPT-generated musculoskeletal images.

In the evolving landscape of medical research and radiology, effective communication of intricate ideas is imperative, with visualizations playing a crucial role. This study explores the transformative potential of ChatGPT4, a powerful Large Language Model (LLM), in automating the creation of schematics and figures for radiology research papers, specifically focusing on its implications for musculoskeletal studies. Deploying ChatGPT4, the study aimed to assess the model's ability to generate anatomical images of six large joints-shoulder, elbow, wrist, hip, knee, and ankle. Four variations of a text prompt were utilized, to generate a coronal illustration with annotations for each joint. Evaluation parameters included anatomical correctness, correctness of annotations, aesthetic nature of illustrations, usability of figures in research papers, and cost-effectiveness. Four panellists performed the assessment using a 5-point Likert Scale. Overall analysis of the 24 illustrations encompassing the six joints of interest (4 of each) revealed significant limitations in ChatGPT4's performance. The anatomical design ranged from poor to good, all of the illustrations received a below-average rating for annotation, with the majority assessed as poor. All of them ranked below average for usability in research papers. There was good agreement between raters across all domains (ICC = 0.61). While LLMs like ChatGPT4 present promising prospects for rapid figure generation, their current capabilities fall short of meeting the rigorous standards demanded by musculoskeletal radiology research. Future developments should focus on iterative refinement processes to enhance the realism of LLM-generated musculoskeletal schematics.

Anatomical design and production of a novel three-dimensional co-culture system replicating the human flexor digitorum profundus enthesis.

The enthesis, the specialized junction between tendon and bone, is a common site of injury. Although notoriously difficult to repair, advances in interfacial tissue engineering techniques are being developed for restorative function. Most notably are 3D invitro co-culture models, built to recreate the complex heterogeneity of the native enthesis. While cell and matrix properties are often considered, there has been little attention given to native enthesis anatomical morphometrics and replicating these to enhance clinical relevance. This study focuses on the flexor digitorum profundus (FDP) tendon enthesis and, by combining anatomical morphometrics with computer-aided design, demonstrates the design and construction of an accurate and scalable model of the FDP enthesis. Bespoke 3D-printed mould inserts were fabricated based on the size, shape and insertion angle of the FDP enthesis. Then, silicone culture moulds were created, enabling the production of bespoke anatomical culture zones for an invitro FDP enthesis model. The validity of the model has been confirmed using brushite cement scaffolds seeded with osteoblasts (bone) and fibrin hydrogel scaffolds seeded with fibroblasts (tendon) in individual studies with cells from either human or rat origin. This novel approach allows a bespoke anatomical design for enthesis repair and should be applied to future studies in this area.

Evaluation of micromotion in multirooted root analogue implants embedded in synthetic bone blocks: an in vitro study

BackgroundWhile conventional threaded implants (TI) have proven to be effective for replacing missing teeth, they have certain limitations in terms of diameter, length, and emergence profile when compared to customised root analogue implants (RAI). To further investigate the potential benefits of RAIs, the aim of this study was to experimentally evaluate the micromotion of RAIs compared to TIs.MethodsA 3D model of tooth 47 (mandibular right second molar) was segmented from an existing cone beam computed tomography (CBCT), and a RAI was designed based on this model. Four RAI subgroups were fabricated as follows: 3D-printed titanium (PT), 3D-printed zirconia (PZ), milled titanium (MT), milled zirconia (MZ), each with a sample size of n = 5. Additionally, two TI subgroups (B11 and C11) were used as control, each with a sample size of n = 5. All samples were embedded in polyurethane foam artificial bone blocks and subjected to load application using a self-developed biomechanical Hexapod Measurement System. Micromotion was quantified by analysing the load/displacement curves.ResultsThere were no statistically significant differences in displacement in Z-axis (the loading direction) between the RAI group and the TI group. However, within the RAI subgroups, PZ exhibited significantly higher displacement values compared to the other subgroups (p < 0.05). In terms of the overall total displacement, the RAI group showed a statistically significant higher displacement than the TI group, with mean displacement values of 96.5 µm and 55.8 µm for the RAI and TI groups, respectively.ConclusionsThe RAI demonstrated promising biomechanical behaviour, with micromotion values falling within the physiological limits. However, their performance is less predictable due to varying anatomical designs.

Peritoneal Carcinomatosis and Situs Inversus Totalis: A Rare Case Report

Gastric cancer remains one of the foremost important cancers around the world because it positions as the fifth most common cancer and the fourth driving cause of cancer passing all-inclusive. Situs inversus totalis (SIT) alludes to a turned-around area of the stomach and thoracic organs. The heart is found on the correct side of the chest (dextrocardia) with a total inversion of the heart chambers. The ordinary pulmonary anatomy is additionally turned around, so the cleared-out lung has three flaps and the proper lung has two flaps. In addition, the liver and gallbladder are found on the cleared-out side of the guts, though the spleen and stomach are found on the proper side. The remaining internal structures are moreover a reflected picture of the typical. This natural irregularity is outstandingly remarkable with a pace of one case in 10,000 births. SIT might be a phenomenal intrinsic irregularity that stances unique difficulties amid careful organization. Preoperative organizing, counting imaging and the mindful idea of careful techniques, are fundamental for powerful outcomes in SIT patients with gastric disease. The use of laparoscopic and automated procedures has seemed, by all accounts, to be secure and practical in this calm people. Advanced research is expected to push ahead the comprehension of the aetiology and optimal organization of SIT patients with gastric disease. SIT could be a remarkable innate eccentricity that stances unique difficulties during careful organization. Preoperative orchestrating, counting imaging and the wary idea of surgeries, are crucial for productive outcomes in SIT patients with gastric disease. Advanced careful fitness is expected to play out a definite lymphadenectomy in calm with SIT by envisioning the exact reflected image of the existing frameworks during the activity. The diligent had an ordinary intra-and postoperative course and was taken after up at the short-term division with no demonstration of rehash. All in all, medical procedures in comprehension with peritoneal disease and SIT can be safely performed by paying thought to the improved anatomic designs amid the activity.

Translucent monolithic zirconia titanium-supported FP1 full-arch prosthesis: A novel proof of concept to address esthetic, functional, and biologic challenges.

Despite the wide clinical use of translucent zirconia for full-arch implant prostheses, reduced flexural strength and fracture toughness compared with high-strength opaque zirconia needs to be addressed. A novel proof of concept for FP1 full-arch prosthesis featured by translucent monolithic zirconia and titanium framework was presented. Computer-guided implant planning and surgery were executed and digitally designed FP1 temporary prosthesis prefabricated. Implant and prosthetic placement were achieved with a set of three-dimensional (3D)-printed templates. Implants were immediately loaded. After 4 months intraoral optical scan was taken to record implant coordinates, soft tissue anatomy, and temporary FP1 prosthesis. A novel digital workflow was used to design and mill overlaying translucent zirconia and anatomically shaped titanium framework with a scalloped soft-tissue interface. Final FP1 prosthesis was assembled cementing zirconia jacket on titanium counterpart. Translucent zirconia supported by titanium framework can address esthetic and mechanical requirements of FP1 full-arch prosthesis, minimizing risk of fracture and providing a rigid and passive joint with supporting implants. The smooth and highly polished titanium surface with an anatomic design, tightly matching scalloped soft tissue interface, can limit food impaction, air and saliva leakage and contribute to overall biologic integration of FP1 full-arch prosthesis. Translucent monolithic zirconia featured with anatomically shaped titanium framework with scalloped transmucosal part, combining a pleasant esthetic outcome with increased flexural strength and fracture toughness, may be indicated to increase the clinical performance of FP1 full-arch prosthesis.

The effect of femoral prosthesis design on patellofemoral contact stresses in total knee arthroplasty: a case–control study with mid-term follow-up minimum 3-year follow-up

BackgroundTo investigate the differences in postoperative patellofemoral pressures and patellar tracking during at least three years of follow-up in patients using three prostheses of different designs in total knee arthroplasty (TKA) without patellar resurfacing.Methods: Radiographic investigationsThe study included 401 patients who had a total of 480 knee prostheses implanted without patellar resurfacing. The prostheses used were Genesis II (external rotation design of femoral prosthesis), Triathlon (design with deep trochlear grooves), and Gemini MK II (deepening of trochlear groove and lateral condylar protrusion that closely follows the anatomical shape). The patients' patellar tracking was assessed by measuring patellar tilt and displacement during postoperative follow-up. Furthermore, postoperative knee function and pain were evaluated through range of motion, Knee Society scores (KSS), and Forgotten Joint Score (FJS) to compare the different groups.Finite element analysisConstructing a finite element model of the knee joint of a normal volunteer after total knee arthroplasty using different prostheses for nonpatellar replacement. The three models' von Mises stress distribution heat map, peak contact pressure, and patellar transverse displacement were compared at 30°, 60°, and 90°, respectively.Results: Radiographic investigationsA total of 456 knees of 384 patients were investigated at a 3-year follow-up after TKA without patellar resurfacing. There were no significant differences in patellar tracking between the three groups. Patients with all three prostheses demonstrated favorable clinical outcomes at 3 years postoperatively, with no statistically significant differences in knee scores (91.9 vs 92.3 vs 91.8) or range of motion (127.9° vs 128.5° vs 127.7°) between the groups. However, there was a significant difference between Genesis II and Gemini MK II in the Forgotten Joint Score (59.7 vs 62.4). Patients with persistent postoperative anterior knee pain were present in all three groups (16 vs 12 vs 10), but the incidence was not significantly different.Finite element analysisThe von Mises stress distribution heat map showed that during flexion, the patellofemoral stresses were mainly concentrated on the lateral side of the prosthesis side, and the contact site gradually shifted downward with increasing flexion angle. At the same time, the peak contact stress of the patellofemoral joint increased with the gradual increase in the flexion angle. Genesis II, with a wider and shallower trochlear groove, showed greater patellofemoral stresses and lateral patellar displacement after TKA without patellar resurfacing. The Gemini MK II with a deeper trochlear groove and slightly protruding lateral condyle is more in line with anatomical design, with smaller patellofemoral joint pressure and better patellar tracking.ConclusionsIn TKA without patellar resurfacing, a prosthesis with a deeper trochlear groove, a slightly higher lateral femoral condyle, and a more anatomically designed knee that better matches the patellar morphology should be a better choice.

Two cleft palate simulators of Furlow double-opposing Z- palatoplasty: a comparative study

PurposeThis study aimed to evaluate the efficiency of the porcine tongue for palatoplasty simulation compared to 3D-printed simulators and their surgical education role.Materials and methodsA total of 18 senior cleft surgeons participated in a palatoplasty simulation-based workshop conducted using porcine tongue simulators and 3D-printed simulators. This workshop consisted of a didactic session followed by a hands-on simulation session. Each participant independently used both simulators to perform Furlow double-opposing Z-plasty, which was assessed and scored by senior cleft surgeons using a scoring system including organizational flexibility and ductility, anatomical design simulation, proper incision, proper suturing, and convenience of operation. A paired t test was used for data statistical analysis and a P value < 0.05 was regarded as a statistically significant difference.ResultsAll senior cleft surgeons strongly agreed that the simulation-based workshop was a valuable learning experience, and both simulators were useful and easy to manipulate (P = 1.00). The results of this comparative study showed that a porcine tongue palatoplasty simulator had an effectively significant difference in terms of organizational flexibility and ductility (P = 0.04), and suturing was better than the 3D-printed palatoplasty simulator (P < 0.01). There were no significant differences between the simulators regarding anatomical design simulation (P = 0.76) and incision simulation (P = 0.65).ConclusionBoth porcine tongue simulator and 3D-printed simulator have their unique strengths in surgical education for palatoplasty. Thus, the combined use of a porcine tongue and a 3D-printed cleft palate simulators are efficient as an educational model to practice Furlow double-opposing Z- palatoplasty. The porcine tongue simulators are superior in terms of organizational flexibility, ductility, and suturing simulators, while with the 3D-printed simulator, various palatoplasty techniques can be repeatedly practiced with better-simulated face and oral cavity.

Total knee arthroplasty: do newer CR implants yield better results? A single center prospective study.

The aim of this study was to compare whether the newest TKA prosthesis (Persona) gives improved clinical outcomes due its more anatomical design in comparison to older prostheses (balanSys). This study included a total of 89 patients planned for TKA from June 2018 to September 2019. Outcomes such as Knee Injury and Osteoarthritis Outcome Score (KOOS), range of motion (ROM), numeric pain rating scale (NRS), analgesics and alignment were recorded next to patient characteristics and complications. Our results showed a significant improvement in NRS, ROM and functional scores postoperatively compared to preoperatively for both the Persona and the balanSys implants. Although the flexion ROM for the Persona group was higher at 6 and 12 months postoperative compared to the balanSys, this was mainly a regaining of the preoperative ROM. Throughout all timepoints, there were no statistically significant differences observed in NSAID and opioid usage between the balanSys and Persona groups. Both implants are safe and efficient to use in the treatment of knee osteoarthritis. Although Persona had an improved postoperative flexion, this did not have an impact on any of the patient-reported outcomes.

A new enigmatic lacustrine trackway in the upper Miocene of the Sierra de las Cabras (Jumilla, Murcia, Spain)

A new fossil trackway is described in the upper lacustrine Miocene in the Prebetic Zone of the Iberian Peninsula, in Jumilla town (Murcia region) called Aenigmatipodus jumillensis nov. ichnogen. nov. ichnosp. This trackway consists of a pattern made up of sets of three tracks or triads, which are subparallel to each other, arranged in alternate groups. Each track presents a depression formed by a central body that is three times as long as it is wide, with straight or slightly curved walls, with two shorter bodies placed at the ends, one of the ends being shorter and more pronounced than the opposite, which is longer and stretched. All the biomechanical possibilities compatible with an anatomical design that could leave the impression of three alternate triads of tracks are analysed. The supports are only from the extremities on one side of the organism (left or right), the displacement being by translation. It is concluded that it had to be a large arthropod (metre scale), with a hexapod or decapod (less probably octopod), which had to be dragged laterally by a current in a very shallow lake or wetland environment. To date, no fossil organism is known, nor its current equivalent, that corresponds to these characteristics.

Medialized Dome and Anatomic Onlay Patella Designs in the Modern Posterior Stabilized Rotating Platform Total Knee Arthroplasty Demonstrate No Clinical or Radiological Differences at One Year

BackgroundA successful outcome after total knee arthroplasty (TKA) includes the restoration of patellofemoral function. Modern patella component designs in TKA include a medialized dome and more recently, an anatomic design. There is a paucity of literature comparing these 2 implants. MethodsThis prospective nonrandomized study examined 544 consecutive TKAs with patella resurfacing using a posterior-stabilized, rotating platform knee prothesis performed by a single surgeon. A medialized dome patella design was used in the first 323 cases and an anatomic design in the subsequent 221 cases. Patients were assessed preoperatively, at 4 weeks and 1-year post-TKA for Oxford Knee Score (OKS) (total, pain, and kneeling components) and range of movement (ROM). Radiolucent lines (RLLs), patellar tilts and displacements, as well as reoperations were assessed at 1-year post-TKA. ResultsAt 1-year post-TKA, both groups demonstrated similar improvements in ROM, OKS, pain, and kneeling scores, and had a similar incidence of fixed-flexion deformity (all P > .05). Radiographically, there was no clinically significant difference in the incidence of RLLs, patellar tilts, and displacements. The prevalence of reoperations (1.8 versus 3.2%, P = .526) was similar between the designs with no patella-related complications. ConclusionBoth medialized dome and anatomic patella designs result in improved ROM and OKS with no patella-related complications. However, our study showed no differences between the designs at 1 year.

Customized Cost-Effective Cranioplasty for Large Asymmetrical Defects

Cranioplasty or cranial reconstruction is always a challenging procedure even for experienced surgeons. In this study, two different design techniques for customized cranial prostheses are assessed for cranial reconstruction. Mirror reconstruction is one of the commonly used reconstruction techniques that fails when cranial defects cross the midline of symmetry. Hence, there is a need for a design technique for the reconstruction of cranial defects irrespective of their location on the symmetrical plane. The anatomical reconstruction technique demonstrates its applicability for a wide spectrum of complex skull defects irrespective of the defective position in the anatomical structure. The paper outlines a methodological procedure involving a multi-disciplinary approach involving physicians and engineers in the design and reconstruction of customized cranial implants for asymmetrical skull defects. The proposed methodology is based on five foundation pillars including the multi-disciplinary approach, implant design process, additive-manufactured implant, implant fitting analysis, and cost and time analysis for the customized implant. The patient’s computed tomography scan data are utilized to model a customized cranial implant, which is then fabricated using electron beam melting technology. The dimensional validation of the designed and fabricated titanium implant based on the anatomical approach results in a precision of 0.6345 mm, thus indicating a better fit than the standard mirroring method. The results of fitting accuracy also reveal that the manufactured implant’s average deviation is very close to the planned reconstruction area with an error less than 1 mm, suggesting that the customized titanium implant fits the skull model quite precisely. The cost and time analysis reports that the cost for producing a customized cranial implant using electron beam melting technology is around USD 217.5 and the time taken to build is approximately 14 h and 27 min, which is low when compared to other studies. The cost and time analysis also demonstrates that the proposed design would be less burdensome to patients when compared to standard practice. Therefore, the new anatomical design process can be used effectively and efficiently to treat a number of diverse cranial abnormalities with the enhanced cranial implant design.

Unstable distal radius fractures fixation with a 2.4 mm volar variable-angle locking plate: radiological and functional assessment

Background: The main objective of this observational study was to evaluate the functional and radiological outcome of variable angle volar plates in intra-articular distal end radius fractures. Methods: Patients with distal end radius fractures (AO type 3C) treated operatively between Jan 2020 and Dec 2020 and then followed up for at least 12 months. A total of 32 patients (11 men and 21 women) with a mean age of 51.9 years were included in the study. The functional outcome was assessed by using modified Mayo wrist score (MMWS), disabilities of the arm, shoulder, and hand (DASH) score, wrist range of motion (ROM) and grip strength relative to the uninjured side and radiological assessment of radial height, volar tilt, and radial inclination. Results: MMWS and DASH scores improved postoperatively over time. Signs of radiographic union started around 12 weeks after surgery. The most common complication observed was finger and wrist stiffness, which was resolved with active wrist and finger movements. Non-union or hardware-related complications/ late complications such as tendon irritation/attrition were not observed with variable angle volar locking plates. Conclusions: Distal end radius fracture fixation with variable angle plate gives favourable radiological and clinical outcomes. These results can be owed to features such as low profile, variable locking, anatomical design and implant biomechanics. The surgeon determined angulation of the distal row of screw fixation may decrease the incidence of joint penetration and improve fixation of radial styloid and lunate facet stability.

Comparison of Femoral Component Rotation between Robotic-Assisted vs. Soft-Tissue Tensor Total Knee Arthroplasty with Anatomic Implants.

Background and Objectives: Total knee arthroplasty (TKA) is the most effective treatment method for end-stage osteoarthritis. One of the most important aspects of this surgery is adequate implant positioning, as it guarantees the desired outcome of restoring limb biomechanics. Surgical technique is being continuously improved along with hardware development. There are two novel devices designed to help establish proper femoral component rotation: soft-tissue tensor and robotic-assisted TKA (RATKA). This study compared the femoral component rotation achieved with the use of three methods: RATKA, soft tissue tensioner and the conventional measured-resection technique, all of them utilizing anatomical design prosthesis components. Materials and Methods: A total of 139 patients diagnosed with end-stage osteoarthritis underwent total knee arthroplasty between December 2020 and June 2021. After the surgery, they were divided into three groups depending on procedure technique and implant type: Persona (Zimmer Biomet) + Fuzion Balancer, RATKA + Journey II BCS or conventional TKA + Persona/Journey. Postoperatively, a computed tomography examination was performed in order to measure femoral component rotation. All three groups were compared independently during statistical analysis. Fisher's exact, Kruskal-Wallis and Dwass-Steel-Crichtlow-Fligner tests were used for particular calculations. Results: Statistically significant differences in femoral component rotation between groups were noticed. However, in terms of values other than 0° in external rotation, no significant variance was revealed. Conclusions: Additional total knee arthroplasty instruments seem to improve the outcomes of the surgery, providing better component positioning than in the conventional measured-resection technique based only on bone landmarks.

Curve-on-curve technique does not improve tibial coverage in total knee arthroplasty in comparison to tibial tuberosity technique with use of anatomical implants: randomized controlled trial

IntroductionDuring the last years, main attention while performing total knee replacement was paid to femoral component alignment; however, there is still lack of studies concerning tibial baseplate rotational alignment, especially in terms of anatomical designs of knee prosthesis. Some recent studies proved that tibial baseplate malrotation might be a cause of knee pain and patients’ dissatisfaction. The aim of this study was to compare tibial component rotation and its coverage on the tibial plateau achieved with curve-on-curve and tibial tuberosity techniques (t-t technique) with use of anatomic knee designs with asymmetric tibial baseplate.Materials and methodsA total of 88 patients were randomly assigned in a 1:1 ratio to undergo total knee arthroplasty with use of the PERSONA PS (Zimmer Biomet) knee design with an asymmetric baseplate. The rotation of the tibial component was assessed and performed with two different techniques: curve-on-curve technique and tibial tuberosity technique. Tibial component rotation was measured on computed tomography (CT) scans using the method suggested by Benazzo et al. and designed for asymmetrical implants. For the measurement of the tibial bone coverage, the component surface area was outlined and measured on a proper CT section, then the tibial cut surface area was outlined and measured on a section just below the cement level. Pre- and post-operative range of motion was measured by another independent researcher 12 months post-operatively during follow-up visit.ResultsThere was a statistically significant difference between both groups in median value of tibial rotation angle: 7° (interquartile range (IQR) = 0–12) in curve-on-curve technique group vs 2° (IQR-1–7) in tibial tuberosity technique group, probability value (p) = 0.0041, with values above 0 meaning external rotation of the component. There was no statistically significant difference between both groups in terms of range of motion (ROM) with average values of 124.3° ± 13.0° for curve-on-curve technique and 125.6° ± 12.8° for t-t technique with p = 0.45. There was a statistically insignificant difference between both groups in terms of coverage percentage in slight favor for curve-on-curve technique (85.9 ± 4.2 vs 84.5 ± 4.8, p = 0.17).ConclusionIn this study, no difference between the groups in terms of tibial bone coverage and range of motion was proved, even though both techniques differed significantly with values of tibial rotation. Future studies should be focused on influence of specific values of tibial rotation on patient-reported outcomes and survivorship of anatomic knee implants.

Simulation device for shoulder reductions: overview of prototyping, testing, and design instructions

BackgroundShoulder dislocations are common occurrences, yet there are few simulation devices to train medical personnel on how to reduce these dislocations. Reductions require a familiarity with the shoulder and a nuanced motion against strong muscle tension. The goal of this work is to describe the design of an easily replicated, low-cost simulator for training shoulder reductions.Materials and methodsAn iterative, stepwise engineering design process was used to design and implement ReducTrain. A needs analysis with clinical experts led to the selection of the traction-countertraction and external rotation methods as educationally relevant techniques to include. A set of design requirements and acceptance criteria was established that considered durability, assembly time, and cost. An iterative prototyping development process was used to meet the acceptance criteria. Testing protocols for each design requirement are also presented. Step-by-step instructions are provided to allow the replication of ReducTrain from easily sourced materials, including plywood, resistance bands, dowels, and various fasteners, as well as a 3D-printed shoulder model, whose printable file is included at a link in the Additional file 1: Appendix.ResultsA description of the final model is given. The total cost for all materials for one ReducTrain model is under US $200, and it takes about 3 h and 20 min to assemble. Based on repetitive testing, the device should not see any noticeable changes in durability after 1000 uses but may exhibit some changes in resistance band strength after 2000 uses.DiscussionThe ReducTrain device fills a gap in emergency medicine and orthopedic simulation. Its wide variety of uses points to its utility in several instructional formats. With the rise of makerspaces and public workshops, the construction of the device can be easily completed. While the device has some limitations, its robust design allows for simple upkeep and a customizable training experience.ConclusionA simplified anatomical design allows for the ReducTrain model to serve as a viable training device for shoulder reductions.

Anatomically Designed Triboelectric Wristbands with Adaptive Accelerated Learning for Human-Machine Interfaces.

Recent advances in flexible wearable devices have boosted the remarkable development of devices for human-machine interfaces, which are of great value to emerging cybernetics, robotics, and Metaverse systems. However, the effectiveness of existing approaches is limited by the quality of sensor data and classification models with high computational costs. Here, a novel gesture recognition system with triboelectric smart wristbands and an adaptive accelerated learning (AAL) model is proposed. The sensor array is well deployed according to the wrist anatomy and retrieves hand motions from a distance, exhibiting highly sensitive and high-quality sensing capabilities beyond existing methods. Importantly, the anatomical design leads to the close correspondence between the actions of dominant muscle/tendon groups and gestures, and the resulting distinctive features in sensor signals are very valuable for differentiating gestures with data from 7 sensors. The AAL model realizes a 97.56% identification accuracy in training 21 classes with only one-third operands of the original neural network. The applications of the system are further exploited in real-time somatosensory teleoperations with a low latency of <1 s, revealing a new possibility for endowing cyber-human interactions with disruptive innovation and immersive experience.

Comparison of tibial implant positioning between symmetrical and anatomical design implants in unicompartmental knee arthroplasty for Japanese patients.

In unicompartmental knee arthroplasty (UKA) procedures, maximizing the bone coverage of the tibial implant and eliminating the medial and posterior overhang would be optimal. We commonly used Physica ZUK® (ZUK), which is a symmetrical design. Alternatively, since Persona Partial Knee® (PPK) was developed in 2017 with an anatomical design to improve bone coverage, we started PPK. We hypothesized that the PPK facilitated better bone coverage than the ZUK without obvious overhangs. This study evaluated the bone coverage and the medial and posterior overhang of these differently designed tibial implants. Seventy-nine knees from 68 patients who underwent UKA were evaluated. Cases were categorized into the ZUK (41 knees) and PPK (38 knees) groups. CT images were acquired before surgery and 1week after surgery. We measured the tibial bone coverage, and the medial and posterior overhang by 3D software. The bone coverages were 103.8 ± 4.8% and 102.0 ± 3.0%, the medial overhangs were 2.2 ± 1.2mm and 1.4 ± 1.1mm, and the posterior overhangs were 0.6 ± 1.3mm and 0.4 ± 1.2mm for the ZUK and PPK groups, respectively. The bone coverage and medial overhang were significantly different between the groups, with ZUK being larger. Patients who received PPK had significantly smaller medial overhangs and better bone coverage. PPK is more likely to give better results than ZUK.

Флексоры локтевого сустава у кошки домашней

The article presents the anatomical and functional characteristics of the flexor muscles of the elbow joint in a domestic cat. The study was performed at the Department of Anatomy and Histology of Animals named after Professor A. F. Klimov of the Moscow State Academy of Veterinary Medicine and Biotechnology – MBA named after K .I. Skryabin. The methods of conventional and fine anatomical dissection under the control of a binocular magnifying glass, biomechanical modeling of the locomotor act and subsequent identification of patterns and features of the structure of the studied skeletal muscles were used. The object of the study was a domestic cat (n=12), mestizos of both sexes aged from 2 to 9 years. Based on the conducted studies, the general patterns of the anatomical structure of the muscles of the elbow joint, characteristic of representatives of other taxonomic groups, and species-specific features due to the biomechanical features of the motor behavior of cats have been established in the domestic cat. Additions have been made to the anatomical design of the shoulder muscle: the presence of three shoulder muscle bellies, one of which has a close relationship with the shoulder muscle, the heads of the biceps of the shoulder muscle are presented, the attachment points of the studied muscles and their tendon endings are specified. Fascial consolidation of the brachial muscle bellies and biceps heads was found, which may reflect the participation of muscles in preventing injury to the structures of the elbow joint. The optional functional purpose of the shoulder muscle, consisting in supination of the forearm, is substantiated.

Anatomical and topographic features of the quadriceps femoris muscle in the Amur tiger

The article presents the specific features of the anatomical design of the quad- riceps femoral muscle in the Amur tiger. The aim of the study is to establish anatomical and topographic features and skeletotopic landmarks of the quadriceps femoral muscle in the Amur tiger, as well as to assess the functional significance of the studied structures. It was found that its straight head in its distal part has a muscle-tendon method of attachment to the kneecap. It is shown that the terminal tendons of the lateral and medial heads of the quadriceps femoris fuse with the plate-shaped tendons of the lateral and medial parts of its intermediate head. A more extensive area of fixation is characterized, in comparison with other heads, by the lateral head extending to the top of the cranial tubercle of the kneecap. The intermediate head with its distal end, together with the joint capsule, is fixed in the area of the articular surface of the kneecap. The study was performed at the Department of Anatomy and Histology of Animals named after Professor A.F. Klimova, Moscow State Academy of Veterinary Medicine and Biotechnology – MBA named after K.I. Scriabin. The object of study was the Amur tiger. The material for the study was pelvic limbs, without external signs of pathologies. We used methods of conventional and fine anatomical dissec- tion of muscles under the control of a binocular magnifier “Micromed HR 350 S”, as well as biomechanical modeling of a static-locomotor act. Based on the conducted studies, we have identified additional collateral lateral and medial menisco-femoral ligaments in the tiger, which stabilize the menisci and strengthen the knee joint. The revealed features of the mac- roarchitecture of the kneecap in a tiger can provide optimal conditions for the functioning of the quadriceps femoral muscle and biomechanical perfection of the knee joint