Biomechanical Changes Following Knee Arthroplasty During Sit-To-Stand Transfers: Systematic Review

BackgroundKnee arthroplasty (KA) is a common and effective surgical procedure that allows patients with knee osteoarthritis to restore functional ability and relieve pain. Sit-to-stand is a common demanding task during activities of daily living and is performed more than 50 times per day. The purpose of this systematic review is to obtain a comprehensive understanding of biomechanical changes during sit-to-stand transfers following KA.MethodsRelevant articles were selected through MEDLINE (PubMed), Scopus, Embrace, and Web of Science. Articles were included if they met the following inclusion criteria: (1) underwent KA without restriction on the arthroplasty design, (2) involve kinematic, kinetic, or muscle activity variables as the primary outcome measure, (3) evaluated sit-to-stand, and (4) were written in English.ResultsA total of 13 articles were included in the current systematic review. The KA group exhibited altered movement patterns as compared to healthy controls. Considering the time course of recovery, improvement in knee joint kinematics was found up to 2 years but kinetic changes indicate intensified contralateral limb loading. For comparisons for limbs, limb differences were apparent, but those differences were resolved by 1 year.ConclusionDespite the inevitable changes in kinematics, kinetics, and muscle activity in sit-to-stand since KA, it appears to be important to restore quadriceps strength for the operative limb in order to minimize risk for subsequent joint problems.     

A Biomechanical Foot-Worn Device Improves Total Knee Arthroplasty Outcomes

Background

Biomechanics after total knee arthroplasty (TKA) often remain abnormal and may lead to prolonged postoperative recovery. The purpose of this study is to assess a biomechanical therapy after TKA.

Neuromuscular and biomechanical landing alterations persist in athletes returning to sport after anterior cruciate ligament reconstruction

BackgroundAnterior cruciate ligament reconstructed (ACLR) athletes show increased hamstrings activation and decreased knee flexion moments (KFMs) during single leg landing tasks at time of return-to-sport (RTS). Although these landing alterations seem protective in the short term, they might become undesirable if they persist after RTS. Therefore, the main aim of this study was to investigate whether those landing alterations persist in the months following RTS.MethodsSixteen athletes who had an ACLR performed five unilateral landing tasks at three different time points (at RTS, and at 3 and 6 months after RTS) while KFMs and hamstrings activation were recorded. The following clinical parameters were registered: isokinetic strength of quadriceps and hamstrings, ACL return-to-sport after injury scale (ACL-RSI), Tampa scale of kinesiophobia, self-reported instability and single leg hop distance. A one-way repeated measures analysis of variance (ANOVA) was used to assess whether landing deficits changed over time. Additionally, an explorative analysis was performed to assess whether those athletes whose deficits persisted the most could be identified based on baseline clinical parameters.ResultsThe ANOVA showed no differences in landing deficits between sessions, indicating persisting reduced KFMs and increased hamstrings activation in the injured leg compared with the contralateral leg. A significant improvement of the quadriceps concentric strength (at 120°/s), ACL-RSI score and jump distance of the single leg hop was found over time.ConclusionsLanding alterations were not resolved 6 months after RTS. Additional interventions may be needed to normalize landing alterations prior to return to sport.     

Gait kinetics impact shoe tread wear rate

BackgroundAdequate footwear is an important factor for reducing the risk of slipping; as shoe outsoles wear down, friction decreases, and slip and fall risk increases. Wear theory suggests that gait kinetics may influence rate of tread wear.Research questionDo the kinetics of walking (i.e., the shoe-floor force interactions) affect wear rate?MethodsFourteen participants completed dry walking trials during which ground reaction forces were recorded across different types of shoes. The peak normal force, shear force, and required coefficient of friction (RCOF) were calculated. Participants then wore alternating pairs of shoes in the workplace each month for up to 24 months. A pedometer was used to track the distance each pair of shoes was worn and tread loss was measured. The wear rate was calculated as the volumetric tread loss divided by the distance walked in the shoes. Three, mixed linear regression models were used to assess the impact of peak normal force, shear force, and RCOF on wear rate.ResultsWear rate was positively associated with peak RCOF and with peak shear force, but was not significantly related to peak normal forces.SignificanceThe finding that shear forces and particularly the peak RCOF are related to wear suggests that a person’s gait characteristics can influence wear. Therefore, individual gait kinetics may be used to predict wear rate based on the fatigue failure shoe wear mechanism.     

Evaluating the influence of prostate-specific antigen kinetics on metastasis in men with PSA recurrence after partial gland therapy

Purpose

Although current Delphi Consensus guidelines do not recommend a specific definition of biochemical recurrence after partial gland therapy, these guidelines acknowledge that serial prostate-specific antigen (PSA) tests remain the best marker for monitoring disease after treatment. The purpose of this study was to determine whether PSA velocity at failure per the Phoenix (nadir + 2 ng/mL) definition is associated with metastasis and prostate cancer-specific mortality (PCSM) in a cohort of patients who experienced PSA failure after partial gland therapy.

Conversion of a renewable bio-resource to a functional composite material: Product design,comprehensive characterization and adsorption of 2,4-D herbicide

Based on the opinion of “utilizing waste resources to treat waste”, a sustainable resource waste was transformed into a useful and functional material by a comprehensive experimental setup. A high surface area lentil processing waste-based activated carbon was synthesized by microwave-assisted K₂CO₃ chemical activation and then successfully converted into a ferrospinel composite. The ferrospinel composite was characterized with BET, FTIR, XRD, XPS, FE-SEM, EDX mapping, Raman and VSM techniques and the detailed characterization analysis confirmed the successful formation of the ferrospinel composite. It was also applied as an effective adsorbent material in the treatment of 2,4-dichlorphenoxyacetic acid herbicide bearing wastewater. The pseudo-second order model better defined the kinetic pathway of the adsorption while the isothermal data indicated the best suitability to Langmuir model. The maximum adsorption capacity of the ferrospinel composite towards 2,4-dichlorophenoxyacetic acid was 400 mg/g at 45 °C. Thermodynamic studies showed the favorability and spontaneity of the adsorption process.