Impact of intra- and extramedullary alignment on blood loss in total knee arthroplasty: a retrospective study.

BACKGROUND: There is a scarcity of scientific data regarding the correlation between alignment techniques during total knee arthroplasty (TKA) and blood loss as well as transfusion rates. This study's hypothesis posited that intramedullary-aligned (IM) TKA exhibits higher blood loss and transfusion rates when contrasted with extramedullary-aligned (EM) TKA. METHODS: We conducted a retrospective examination of 883 patients who underwent total knee arthroplasty (TKA) in 2021 at a solitary orthopedic center in Germany. These patients were divided into two groups based on their tibial alignment technique: extramedullary alignment and intramedullary tibial alignment. RESULTS: In the intramedullary tibial alignment (IM) group, we observed a blood loss of 0.91 L, while in the extramedullary tibial alignment (EM) group, the blood loss was 0.89 L. These values did not demonstrate a significant difference (p = 0.69). Transfusion rates were 0.99% in the IM group and 0.21% in the EM group, and there was no significant distinction between them (Chi-squared test: p > 0.05). CONCLUSION: We observed no statistically significant variance in blood loss between the IM and EM groups. Likewise, there was no substantial disparity in transfusion rates between these groups. It can be concluded that the selection of a knee arthroplasty system incorporating either intramedullary tibial alignment or extramedullary alignment does not significantly impact blood loss.

Pinch Valve Approach for a Biofilm Resistant Mechatronic Intraurethral Artificial Urinary Sphincter.

Stress urinary incontinence is the involuntary leakage of urine during increased abdominal pressure, such as coughing, sneezing, laughing, or exercising. It can have a significant negative impact on a person's quality of life and can result in decreased physical activity and social isolation. The presented closure mechanism for a mechatronic intraurethral artificial urinary sphincter is designed to be inserted minimally invasive into the urethra. The device consists of a solid shell, which serves as a housing for the electronics and is designed to enable fixation in the urethra. During micturition, the urine flows through the system, where it is guided through an elastic silicone-tube that, on the one hand, enables closure by a squeezing mechanism and, on the other hand, prevents biofilm growth by oscillation at a frequency of 22.5 Hz. The squeezing mechanism consists of a pinch valve system actuated by a piezo motor. The system has been tested under urodynamic conditions and the results show that it is able to close the urethra effectively to restore continence. The device is able to withstand sudden loads and shows good performance in terms of biofilm prevention during first experiments with artificial urine. The results show that the mechatronic intraurethral artificial urinary sphincter has the potential to be an effective and minimally invasive alternative to current treatment options for stress urinary incontinence.Clinical Relevance- This novel concept of a mechatronic intraurethral artificial urinary sphincter presents a promising alternative treatment option for patients suffering from stress urinary incontinence. As it is designed to be inserted minimally invasive, it reduces the impact and complications associated with current treatment options. The future development and testing of the device could lead to a safe and effective option for clinicians to offer their patients with stress urinary incontinence, which can improve their quality of life, and decrease costs for society and healthcare systems.

Spontaneous shrinkage drives macromolecule encapsulation into layer-by-layer assembled biopolymer microgels.

HYPOTHESIS: Recently, the anomalous shrinkage of surface-supported hyaluronate/poly-l-lysine (HA/PLL) microgels (µ-gels), which exceeds that reported for any other multilayer-based systems, has been reported [1]. The current study investigates the capability of these unique µ-gels for the encapsulation and retention of macromolecules, and proposes the shrinkage-driven assembly of biopolymer-based µ-gels as a novel tool for one-step surface biofunctionalization. EXPERIMENTS: A set of dextrans (DEX) and their charged derivatives - carboxymethyl (CM)-DEX and diethylaminoethyl (DEAE)-DEX - has been utilized to evaluate the effects of macromolecular mass and net charge on µ-gel shrinkage and macromolecule entrapment. µ-gels formation on the surface of silicone catheters exemplifies their potential to tailor biointerfaces. FINDINGS: Shrinkage-driven µ-gel formation strongly depends on the net charge and mass content of encapsulated macromolecules. Inclusion of neutral DEX decreases the degree of shrinkage several times, whilst charged DEXs adopt to the backbone of oppositely charged polyelectrolytes, resulting in shrinkage comparable to that of non-loaded µ-gels. Retention of CM-DEX in µ-gels is significantly higher compared to DEAE-DEX. These insights into the mechanisms of macromolecular entrapment into biopolymer-based µ-gels promotes fundamental understanding of molecular dynamics within the multilayer assemblies. Organization of biodegradable µ-gels at biomaterial surfaces opens avenues for their further exploitation in a diverse array of bioapplications.

A Novel Concept for Unidirectional Communication With an Active Implant Based on Deliberately Produced Human Body Signals.

A new patient-friendly and discrete approach to build a unidirectional communication path with active implants based on deliberately produced human body signals is presented. The application for which this approach is intended is an artificial urinary sphincter implant, the closure mechanism of which is wirelessly actuated in the event of micturition need. Conventional implant communication methods can be associated with limitations regarding technological implementation and usability, and are used by medical professionals only. In order to enable patients to discretely and directly communicate with their implant without the need for an external handheld device, the feasibility of a communication approach based on manually applied 'knocking' signals on abdominal tissue is examined in the presented work. A gelatin-based phantom model is used to mimic vibro-acoustic properties of human soft tissue in vitro. A piezoelectric element and an electret microphone are applied as sensors for signal detection at the implantation site and are investigated with respect to their suitability for the intended application. Clinical Relevance- The presented implant communication method can contribute to urinary incontinence therapy by enabling patients to discretely and user-friendly actuate their artificial sphincter implant and can provide a basis for future research into new implant communication technologies.

Development of a test bench for the urodynamic simulation of the lower urinary tract.

Stress urinary incontinence restricts the quality of life of affected individuals. To restore continence and increase the quality of life in a long term, the currently applied surgical treatment methods for more severe cases are not sufficient. To support the development of a novel intraurethral artificial sphincter with the goal to replace current systems, a test bench is developed, which simulates the lower urinary tract with regards to its urodynamics. To verify the ability of the implant to maintain continence and allow undisturbed micturition, pressure and flow conditions of the lower urinary tract are reproduced, with the option to automatically conduct test cycles.Clinical relevance- The developed test bench accurately replicates the urodynamics of the lower urinary tract and therefore allows the validation of intraurethral systems.

Electrospun patterned porous scaffolds for the support of ovarian follicles growth: a feasibility study.

Recently, the interest of the scientific community is focused on the application of tissue engineering approach for the fertility restoration. In this paper innovative patterned electrospun fibrous scaffolds were fabricated and used as 3D system for porcine follicles culture. The obtained scaffolds demonstrated to be a suitable support which did not alter or interfere with the typical spherical follicles morphology. The fibrillar structure of the scaffolds mimics the morphology of the healthy native tissue. The use of porcine follicles implied many advantages respect to the use of mouse model. Relevant results showed that more than the scaffold pattern and struts dimension, the selection of proper biomaterials improve the follicles adhesion and development.