The impact of early weight-bearing on results following anterior cruciate ligament reconstruction.

INTRODUCTION: Anterior cruciate ligament (ACL) ruptures are common injuries that typically affect young, physically active individuals and may require surgical reconstruction. Studies have shown that the long time success of ACL reconstruction depends on the surgical technique and the postoperative rehabilitation strategy. However, there is still no consensus on the content of rehabilitation programs. Hence, additional research is required to elucidate the significance of early weight-bearing in the rehabilitation process following ACL reconstruction. The aim of this article is to examine the impact of weight-bearing on the clinical results of ACL reconstruction. MATERIALS AND METHODS: We retrospectively reviewed patient records who had undergone arthroscopic reconstruction using a semitendinosus-gracilis tendon graft for anterior cruciate ligament rupture between January 2018 and December 2020. The study included the data of 110 patients. The patients were split into two groups: Group 1 underwent early weight-bearing, while Group 2 followed a non-weight-bearing regimen for three weeks. We assessed the patients using the anterior drawer test, Lachman test, range of motion, Lysholm knee scale, Cincinnati scale, Tegner scale, International Knee Documentation Committee (IKDC) form and clinical records. Analytical tests were conducted to compare the results. RESULTS: The complication rates did not show a significant difference between the groups. Group 1 had higher frequencies of positive anterior drawer and Lachman tests. The Lysholm and Cincinnati knee scores of patients in Group 1 were notably lower than those of patients in Group 2. Additionally, the Tegner activity scores and IKDC scores of patients in Group 1 were also meaningfully lower than those of patients in Group 2. In Group 1 patients, there was no notable relationship observed between body mass index (BMI) and the results of the anterior drawer test (ADT) or Lachman test. However, patients with a BMI of 25 or higher in Group 1 showed a decrease in postoperative IKDC scores. In Group 2 patients, no significant relationship was identified between BMI and either the ADT or the Lachman test outcome. CONCLUSION: Based on current literature and current rehabilitation guidelines following ACL reconstruction, the decision to initiate early weight-bearing is based on a limited number of studies with low levels of evidence. In our study, we found that patients who followed a non-weight-bearing regimen for 3 weeks after surgery had better mid-term results than those who were allowed to bear weight early. It appears that further prospective studies on this topic are needed to update rehabilitation guidelines in the next.

Integrated particle image velocimetry and fluid-structure interaction analysis for patient-specific abdominal aortic aneurysm studies.

BACKGROUND: Understanding the hemodynamics of an abdominal aortic aneurysm (AAA) is crucial for risk assessment and treatment planning. This study introduces a low-cost, patient-specific in vitro AAA model to investigate hemodynamics using particle image velocimetry (PIV) and flow-simulating circuit, validated through fluid-structure interaction (FSI) simulations. METHODS: In this study, 3D printing was employed to manufacture a flexible patient-specific AAA phantom using a lost-core casting technique. A pulsatile flow circuit was constructed using off-the-shelf components. A particle image velocimetry (PIV) setup was built using an affordable laser source and global shutter camera, and finally, the flow field inside the AAA was analyzed using open-source software. Fluid-structure interaction (FSI) simulations were performed to enhance our understanding of the flow field, and the results were validated by PIV analysis. Both steady-state and transient flow conditions were investigated. RESULTS: Our experimental setup replicated physiological conditions, analyzing arterial wall deformations and flow characteristics within the aneurysm. Under constant flow, peak wall deformations and flow velocities showed deviations within - 12% to + 27% and - 7% to + 5%, respectively, compared to FSI simulations. Pulsatile flow conditions further demonstrated a strong correlation (Pearson coefficient 0.85) in flow velocities and vectors throughout the cardiac cycle. Transient phenomena, particularly the formation and progression of vortex structures during systole, were consistently depicted between experimental and numerical models. CONCLUSIONS: By bridging high-fidelity experimental observations with comprehensive computational analyses, this study underscores the potential of integrated methodologies in enhancing our understanding of AAA pathophysiology. The convergence of realistic AAA phantoms, precise PIV measurements at affordable cost point, and validated FSI models heralds a new paradigm in vascular research, with significant implications for personalized medicine and bioengineering innovations.

Computer-aided ergonomic analysis of primary school furniture dimensions.

The objective of this study was to determine the match level of school furniture with student dimensions and conduct a pilot study to examine practicality of a computer-aided ergonomic analysis software with a Motion Capture System (MoCap) for the purpose of improving school furniture design process in terms of determining optimum dimensions. The research involved measuring the anthropometric data of 218 voluntary primary school students in Mugla, Turkiye and the dimensions of the existing school desks they use. The compatibility between the students' anthropometry and the existing school desks were analysed by using reference equations. Computer-aided ergonomic analysis performed only for seat and desk height. Four virtual human model and ten different school desks in various dimensions were created and evaluated according to joint reaction forces and muscle activations in three different postures by using Anybody Modelling System (AMS). The results of compatibility level showed that there were significant incompatibilities between the students' anthropometry and the existing school desks, with 80% of seat heights and 96% of desk heights being too high. Overall, in order to assess the optimal school desk dimensions, ergonomic analyses provided data indicating reduced joint reaction forces and muscle activations within the musculoskeletal system for the seat and desk height dimensions determined using reference equations. Also, the findings from the ergonomic analysis revealed valuable information on how even minor dimensional modifications to school desks can affect the musculoskeletal system.Practitioner summary: The study examined the impact of simulating student-school desk matching in various sizes and postures within a virtual environment using computer-aided ergonomic analysis software. The analysis focused on specific local areas of the musculoskeletal system to determine optimum school desk dimensions. The results indicated that the software has a potential in facilitating school furniture design based on user's anthropometric measurements. However, a multidisciplinary team is required to make more detailed analysis.

Short, broadband, and polarization-insensitive adiabatic Y-junction power splitters.

Adiabatic Y-junction power splitters have low loss, large bandwidth, high polarization insensitivity, and high tolerance to fabrication errors. However, the adiabatic transition lengths required are generally much longer than other power splitters. Using a nonlinear taper profile can considerably shorten the device length. Here, we introduce a taper profile optimization algorithm based on polynomial functions, which significantly reduces the lengths of the adiabatic power splitters without increasing losses. We experimentally demonstrate the performance of the adiabatic power splitters for minimum feature sizes of 80 nm, 120 nm, and 160 nm on the 220 nm silicon-on-insulator (SOI) platform. Our best device has a minimum feature size of 120 nm and a length of 14 µm, with measured losses of 0.25 dB and 0.23 dB for the transverse electric (TE) and transverse magnetic (TM) modes, respectively, in the 1500-1600 nm region. This device has an average transmission of -3 ± 0.5 dB in the 1500-1600 nm region, indicating highly balanced splitting over a large spectral range.

Optimization of bulk sensitivity for strip, slot, and subwavelength grating-based waveguides for dual-polarization operation.

We propose a dual-polarization optimization method for the bulk sensitivity of silicon-on-insulator (SOI) waveguides by defining a multi-objective function that accounts for the substrate leakage losses. The proposed optimization method was used to design micro-ring resonator bulk sensors with strip, slot, subwavelength grating, and subwavelength grating slot waveguides. The subwavelength grating slot waveguide has a bulk sensitivity of 520 nm/RIU and 325 nm/RIU for the TE and TM modes, respectively, both of which are higher than the bulk sensitivities of strip, slot, and subwavelength grating waveguides. Moreover, our Monte Carlo analysis shows that the subwavelength grating slot waveguide has the highest immunity to fabrication errors.

Effect of suprahyoid muscles on mouth opening with and without lateral pterygoid muscle: 3D inverse dynamic model analysis.

Objective: To evaluate the contribution of suprahyoid muscles to mouth opening in different hyoid bone positions.Methods: The jaw-opening and closing movements were imposed on the 3D inverse dynamic jaw model with and without the lateral pterygoid muscle (LPM). The activation of the muscles was evaluated for eight different positions of the hyoid bone.Results: The muscles with 100% activation provided maximum mouth opening (MMO). When the hyoid bone was replaced, the muscles could achieve MMO at the 135º, 180º, and 225º points with the LPM. Mouth opening was estimated to be 36.8 mm in the absence of the LPM. A jaw opening greater than 36.8 mm was seen when the hyoid bone was repositioned at the 90º, 180º, and 135º points.Discussion: The contribution of suprahyoid muscles to mouth opening varies in different hyoid bone positions, with the inferior and anterior positions having a positive impact.

Optical and electrical design guidelines for ZnO/CdS nanorod-based CdTe solar cells.

An alternative structure to planar CdTe solar cells is realized by coating ZnO/CdS nanorods (NRs) with a CdTe layer. These structures are expected to achieve high-powered conversion efficiencies through enhanced light absorption and charge carrier collection. ZnO NR-based CdTe solar cell efficiencies; however, they have remained well below their planar counterparts, thus hindering NRs in CdTe solar cells' advantages. Here, we analyze the light trapping and carrier collection efficiencies in two types of ZnO NR-based CdTe solar cells through optical and electrical simulations. The buried CdTe solar cells are formed by completely filling the gaps in between ZnO/CdS NRs. This produces a maximum achievable photo-current of 27.4 mA/cm2 when 2000 nm-tall and 20̊-angularly-deviated NRs are used. A short-circuit current density of 27.3 mA/cm2 is achievable with the same geometry for 5 rods/µm2-dense NRs when a moderate CdTe doping density and a CdS/CdTe surface velocity of 1016 cm-3 and 104 cm/s are used, respectively. We reveal the potential of buried CdTe solar cell for high-charge carrier collection and provide a design guideline in order to achieve high short-circuit current densities with ZnO NR-based CdTe solar cells.

Deterministic assembly of channeling cracks as a tool for nanofabrication.

To address the necessity for a predictive computational tool for layout design in crack lithography, a tool for nanowire fabrication, a computational study is carried out using finite element analysis, where crack-free edge and crack-crack interactions are studied for various material combinations. While the first scenario addresses the ability to induce a controlled curvature in a nanowire, the latter provides an estimation of the minimum distance which can be kept between two straight nanowires. The computational study is accompanied by an experimental demonstration on Si/SiO2 multilayers. Finite element results are found to be well aligned with experimental observations and theoretical predictions. Stronger interaction is evident with a curved crack front modeling as well as with increasing first and decreasing second Dundurs' parameters. Therefore cracks can be packed closer with decreasing film stiffness.