Community-Based Cluster-Randomized Trial to Reduce Opioid Overdose Deaths.

BACKGROUND: Evidence-based practices for reducing opioid-related overdose deaths include overdose education and naloxone distribution, the use of medications for the treatment of opioid use disorder, and prescription opioid safety. Data are needed on the effectiveness of a community-engaged intervention to reduce opioid-related overdose deaths through enhanced uptake of these practices. METHODS: In this community-level, cluster-randomized trial, we randomly assigned 67 communities in Kentucky, Massachusetts, New York, and Ohio to receive the intervention (34 communities) or a wait-list control (33 communities), stratified according to state. The trial was conducted within the context of both the coronavirus disease 2019 (Covid-19) pandemic and a national surge in the number of fentanyl-related overdose deaths. The trial groups were balanced within states according to urban or rural classification, previous overdose rate, and community population. The primary outcome was the number of opioid-related overdose deaths among community adults. RESULTS: During the comparison period from July 2021 through June 2022, the population-averaged rates of opioid-related overdose deaths were similar in the intervention group and the control group (47.2 deaths per 100,000 population vs. 51.7 per 100,000 population), for an adjusted rate ratio of 0.91 (95% confidence interval, 0.76 to 1.09; P = 0.30). The effect of the intervention on the rate of opioid-related overdose deaths did not differ appreciably according to state, urban or rural category, age, sex, or race or ethnic group. Intervention communities implemented 615 evidence-based practice strategies from the 806 strategies selected by communities (254 involving overdose education and naloxone distribution, 256 involving the use of medications for opioid use disorder, and 105 involving prescription opioid safety). Of these evidence-based practice strategies, only 235 (38%) had been initiated by the start of the comparison year. CONCLUSIONS: In this 12-month multimodal intervention trial involving community coalitions in the deployment of evidence-based practices to reduce opioid overdose deaths, death rates were similar in the intervention group and the control group in the context of the Covid-19 pandemic and the fentanyl-related overdose epidemic. (Funded by the National Institutes of Health; HCS ClinicalTrials.gov number, NCT04111939.).

Comparison of Ischial Containment and Subischial Sockets Effect on Gait Biomechanics in People With Transfemoral Amputation: A Randomized Crossover Trial.

OBJECTIVE: To compare gait biomechanics of the Northwestern University Flexible Sub-Ischial Vacuum (NU-FlexSIV) Socket to the ischial containment (IC) socket. DESIGN: Randomized crossover trial with 2, 7-week periods. SETTING: Private prosthetic clinics and university research laboratory. PARTICIPANTS: A total of 30 enrolled (n=30); 25 participants completed the study with full (n=18) or partial data (n=7). INTERVENTIONS: Two custom-fabricated sockets (IC and NU-FlexSIV), worn full-time for 7 weeks, with testing at 1, 4, and 7 weeks after socket delivery. MAIN OUTCOME MEASURES: Gait analyses were conducted at 1, 4, and 7 weeks post socket delivery. Differences between sockets in selected gait variables related to hip motion and coronal plane socket stability were assessed. RESULTS: For participants with data for both sockets at week 7 (n=19), there were no significant differences in any gait variables between sockets at self-selected normal walking speed. However, when all participants and all study time points were assessed (n=25), there was a significant main effect of socket (P=.013), with prosthetic side sagittal plane hip range of motion being significantly greater for the NU-FlexSIV Socket at self-selected normal walking speed. There were no other significant effects. CONCLUSIONS: The results suggest that, compared to the IC socket, the NU-FlexSIV Socket did not alter gait biomechanics related to hip motion and coronal plane socket stability in people with unilateral transfemoral amputation.

A 40-year Study of the Factors Associated with Diaphyseal Forearm Fractures in Skiers and Snowboarders.

BACKGROUND: Skiing and snowboarding are popular sports that are associated with a high number of orthopaedic injuries. Diaphyseal forearm fractures are an important subset of these injuries. To our knowledge, factors associated with these injuries, the mechanisms that cause them, and their relative frequencies in skiers and snowboarders have not been described. In addition, it has been proposed that the use of wrist guards may increase the risk of sustaining a diaphyseal forearm fracture; therefore, we sought to explore the relationship between wrist guard use and diaphyseal forearm fractures. QUESTIONS/PURPOSES: (1) What are the relative frequencies and types of diaphyseal forearm fractures in skiers and snowboarders? (2) What factors are associated with these injuries? (3) Is the use of wrist guards associated with an increased risk of forearm fractures? METHODS: This was an unmatched case-control study performed with an injury database from a university-run clinic at the base lodge of a major ski resort. Cases were injured skiers and snowboarders; controls were randomly selected uninjured skiers and snowboarders. Data were collected on the mechanism of injury; experience level; equipment; radiographs; skiing or snowboarding habits; and trail type, defined as green circle (easiest), blue square (intermediate), black diamond (difficult), and double black diamond (most difficult). From this database, we identified 84 patients with diaphyseal forearm fractures, one of which was a Monteggia fracture and was excluded. A logistic regression analysis was used to compare the injured and control groups to identify factors associated with diaphyseal forearm fractures, including wrist guard use. RESULTS: When adjusted for participant days, diaphyseal forearm fractures were more common in snowboarders than skiers (0.03 injuries per 1000 person-days versus 0.004 per 1000 person-days). On multivariable analysis, factors associated with forearm fractures in skiers were younger age (odds ratio 1.08 [95% CI 1.05 to 1.14]; p < 0.01), being a man or boy (OR 11.9 [95% CI 2.5 to 57.2]; p < 0.01), lack of movement at the time of falling (OR 18.2 [95% CI 3.2 to 102.5]; p < 0.01), and skiing on green circle trails compared with black diamond trails (OR 3.6 [95% CI 1.4 to 12.5]; p = 0.04). Factors associated with forearm fractures in snowboarders were younger age (OR 1.08 [95% CI 1.02 to 1.15]; p = 0.01), decreased weight (OR 1.02 [95% CI 1.00 to 1.02]; p < 0.01), snowboarding on gentle terrain (OR 8.4 [95% CI 1.6 to 45.0]; p = 0.01), and snowboarding on groomed terrain compared with other (OR 7.2 [95% CI 1.9 to 28.0]; p < 0.01) or wet, heavy snow (OR 24.8 [95% CI 2.5 to 246.7]; p = 0.01). Wrist guard use was not associated with an increased odds of diaphyseal forearm fracture in skiers or snowboarders. CONCLUSION: Diaphyseal forearm fractures occur more frequently in snowboarders than in skiers. Despite speculation in prior evidence that wrist guards may paradoxically increase the risk of sustaining these injuries, our study suggests that this is not the case and wrist guards are not unsafe to wear. LEVEL OF EVIDENCE: Level III, prognostic study.

Comparison of Ischial Containment and Subischial Sockets on Comfort, Function, Quality of Life, and Satisfaction With Device in Persons With Unilateral Transfemoral Amputation: A Randomized Crossover Trial.

OBJECTIVE: To compare comfort and functional performance of the Northwestern University Flexible Subischial Vacuum (NU-FlexSIV) Socket with the ischial containment (IC) socket in persons with unilateral transfemoral amputation. DESIGN: Randomized crossover trial with two 7-week periods. SETTING: Private prosthetic clinics and university research laboratory. PARTICIPANTS: A total of 30 enrolled (N=30); 25 participants completed the study with full (n=18) or partial data (n=7). INTERVENTIONS: Two custom-fabricated sockets (IC and NU-FlexSIV), worn full-time for 7 weeks, with testing at 1, 4, and 7 weeks after socket delivery. MAIN OUTCOME MEASURES: The primary outcome was change in Socket Comfort Score (SCS) at 7 weeks. Secondary outcomes at 7 weeks included the Orthotic and Prosthetic Users' Survey (OPUS) to assess lower extremity functional status, health-related quality of life, and satisfaction with device, as well as the 5-Times Rapid Sit-to-Stand Test, Four Square Step Test, and T-Test of Agility to assess functional performance. RESULTS: At 7 weeks, the mean SCS for IC (7.0±1.7) and NU-FlexSIV (8.4±1.1) Sockets were significantly different (P<.001; 95% confidence interval, 0.8-2.3). Results from a linear mixed-effects model, accounting for data from all time points, indicated that the SCS was 1.7 (SE=0.45) points higher for the NU-FlexSIV Socket (P<.001). For the secondary outcomes, only OPUS satisfaction with device was significantly better in the NU-FlexSIV Socket after accounting for all data points. CONCLUSIONS: The results suggest that after 7 weeks' accommodation, the NU-FlexSIV Socket was more comfortable and led to greater satisfaction with device than the IC socket in persons with unilateral transfemoral amputation and K3/K4 mobility. Other patient-reported outcomes and function were no different between sockets.

MRI-only occult geriatric hip fractures: is displacement common with nonoperative treatment?

INTRODUCTION: Although surgical fixation is routinely recommended for geriatric hip fractures, nonoperative treatment may be an option for certain stable fracture patterns. Occult hip fractures are nondisplaced fractures not evident on radiographs, but display intraosseous edema on MRI. Our aim is to report the rate of nonoperative treatment failure in patients with occult geriatric hip fractures. METHODS: All nonoperatively treated femoral neck or intertrochanteric femur fractures (AO/OTA 31A and 31B) from 2003 to 2018 were identified. Patients older than 65 years with negative radiographs but a hip fracture evident on MRI were included. Patients who died prior to fracture displacement or union were excluded. Charts and imaging were reviewed for demographic data, fracture type, clinical course, displacement, and whether corrective surgery was performed. RESULTS: Of 15 final study patients, there were 6 femoral neck and 9 intertrochanteric fractures. Two fractures displaced, both requiring surgery (2/15; 13.3%). Both displacements occurred in the femoral neck group (2/6; 33%) compared to none in the intertrochanteric cohort (0/9; 0%). This trend did not reach statistical significance (p = 0.14). CONCLUSION: Thirty-three percent (2/6, 33%) of femoral neck fractures displaced and required surgery. The remainder of the cohort (13/15, 87%) healed without complication, including all of the intertrochanteric fractures (9/9, 100%). Although this difference did not reach statistical significance, the results may better inform treatment discussions for geriatric patients with occult hip fractures diagnosed by MRI. LEVEL OF EVIDENCE: Level III.

Common Upper Extremity Fracture Eponyms: A Look Into What They Really Mean.

Eponyms, whereas commonly used in hand surgery, are perhaps misused as often as they are used correctly. Many commonly used eponyms, such as Colles fracture, Barton fracture, Smith fracture, and Bennett fracture, were actually described decades before the development of radiographs. The goal of this article is to revisit the original descriptions of commonly used eponymous terms for distal radius and first metacarpal base fractures to provide clarity and enhance understanding of what these eponyms actually mean.

Effect of bias voltage and temperature on lifetime of wireless neural interfaces with Al 2O3 and parylene bilayer encapsulation.

The lifetime of neural interfaces is a critical challenge for chronic implantations, as therapeutic devices (e.g., neural prosthetics) will require decades of lifetime. We evaluated the lifetime of wireless Utah electrode array (UEA) based neural interfaces with a bilayer encapsulation scheme utilizing a combination of alumina deposited by Atomic Layer Deposition (ALD) and parylene C. Wireless integrated neural interfaces (INIs), equipped with recording version 9 (INI-R9) ASIC chips, were used to monitor the encapsulation performance through radio-frequency (RF) power and telemetry. The wireless devices were encapsulated with 52 nm of ALD Al2O3 and 6 µm of parylene C, and tested by soaking in phosphate buffered solution (PBS) at 57 °C for 4× accelerated lifetime testing. The INIs were also powered continuously through 2.765 MHz inductive power and forward telemetry link at unregulated 5 V. The bilayer encapsulated INIs were fully functional for ∼35 days (140 days at 37 °C equivalent) with consistent power-up frequencies (∼910 MHz), stable RF signal (∼-75 dBm), and 100 % command reception rate. This is ∼10 times of equivalent lifetime of INIs with parylene-only encapsulation (13 days) under same power condition at 37 °C. The bilayer coated INIs without continuous powering lasted over 1860 equivalent days (still working) at 37 °C. Those results suggest that bias stress is a significant factor to accelerate the failure of the encapsulated devices. The INIs failed completely within 5 days of the initial frequency shift of RF signal at 57 °C, which implied that the RF frequency shift is an early indicator of encapsulation/device failure.

SELF ALIGNED TIP DEINSULATION OF ATOMIC LAYER DEPOSITED AL2O3 AND PARYLENE C COATED UTAH ELECTRODE ARRAY BASED NEURAL INTERFACES.

The recently developed alumina and Parylene C bi-layer encapsulation improved the lifetime of neural interfaces. Tip deinsulation of Utah electrode array based neural interfaces is challenging due to the complex 3D geometries and high aspect ratios of the devices. A three-step self-aligned process was developed for tip deinsulation of bilayer encapsulated arrays. The deinsulation process utilizes laser ablation to remove Parylene C, O2 reactive ion etching to remove carbon and Parylene residues, and buffered oxide etch to remove alumina deposited by atomic layer deposition, and expose the IrOx tip metallization. The deinsulated iridium oxide area was characterized by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy to determine the morphology, surface morphology, composition, and electrical properties of the deposited layers and deinsulated tips. The alumina layer was found to prevent the formation of micro cracks on iridium oxide during the laser ablation process, which has been previously reported as a challenge for laser deinsulation of Parylene films. The charge injection capacity, charge storage capacity, and impedance of deinsulated iridium oxide were characterized to determine the deinsulation efficacy compared to Parylene-only insulation. Deinsulated iridium oxide with bilayer encapsulation had higher charge injection capacity (240 vs 320 nC) and similar electrochemical impedance (2.5 vs 2.5 kΩ) compared to deinsulated iridium oxide with only Parylene coating for an area of 2 × 10-4 cm2. Tip impedances were in the ranges of 20 to 50 kΩ, with median of 32 KΩ and standard deviation of 30 kΩ, showing the effectiveness of the self-aligned deinsulation process for alumina and Parylene C bi-layer encapsulation. The relatively uniform tip impedance values demonstrated the consistency of tip exposures.

Genotype-environment-driven dysbiosis in the skin microbiome of ichthyosis.

Monogenic skin disorders such as ichthyosis introduce multiple sources of disturbance to the skin, including the direct biochemical consequences of the genotype, the phenotypic changes in skin physiology, and an altered skin microbiome. The association between changes in the skin microbiome and the disease's genotypic and phenotypic effects are of both ecological and clinical interest but are historically obscured by 1) the limited resolution of metagenomic profiles, and 2) additional sources of variation such as age and topical/oral treatments. Here we characterize the skin microbiome from seven ichthyosis genotypes, at species, strain, and metabolic pathway levels. Critically, we assess the association between these microbiome features and the ichthyosis genotype and phenotype while adjusting for contextual host covariables. We show that the ichthyosis genotype, especially that caused by mutations in TGM1, and the ichthyosis phenotype, particularly transepidermal water loss (TEWL), and personal covariables, such as topical emollients and oral retinoids, collectively, and sometimes antagonistically, influence the species community, strain population, and metabolic potential of the skin microbiome.

BioMapAI: Artificial Intelligence Multi-Omics Modeling of Myalgic Encephalomyelitis / Chronic Fatigue Syndrome.

Chronic diseases like ME/CFS and long COVID exhibit high heterogeneity with multifactorial etiology and progression, complicating diagnosis and treatment. To address this, we developed BioMapAI, an explainable Deep Learning framework using the richest longitudinal multi-'omics dataset for ME/CFS to date. This dataset includes gut metagenomics, plasma metabolome, immune profiling, blood labs, and clinical symptoms. By connecting multi-'omics to asymptom matrix, BioMapAI identified both disease- and symptom-specific biomarkers, reconstructed symptoms, and achieved state-of-the-art precision in disease classification. We also created the first connectivity map of these 'omics in both healthy and disease states and revealed how microbiome-immune-metabolome crosstalk shifted from healthy to ME/CFS. Thus, we proposed several innovative mechanistic hypotheses for ME/CFS: Disrupted microbial functions - SCFA (butyrate), BCAA (amino acid), tryptophan, benzoate - lost connection with plasma lipids and bile acids, and activated inflammatory and mucosal immune cells (MAIT, γδT cells) with INFγ and GzA secretion. These abnormal dynamics are linked to key disease symptoms, including gastrointestinal issues, fatigue, and sleep problems.

Strains to go: interactions of the skin microbiome beyond its species.

An extraordinary biodiversity of bacteria, fungi, viruses, and even small multicellular eukaryota inhabit the human skin. Genomic innovations have accelerated characterization of this biodiversity both at a species as well as the subspecies, or strain level, which further imparts a tremendous genetic diversity to an individual's skin microbiome. In turn, these advances portend significant species- and strain-specificity in the skin microbiome's functional impact on cutaneous immunity, barrier integrity, aging, and other skin physiologic processes. Future advances in defining strain diversity, spatial distribution, and metabolic diversity for major skin species will be foundational for understanding the microbiome's essentiality to the skin ecosystem and for designing topical therapeutics that leverage or target the skin microbiome.

Stakeholder perspectives for possible residual limb monitoring system for persons with lower-limb amputation.

Purpose: To gather ideas from lower-limb prosthesis users and certified prosthetists regarding possible residual limb monitoring system features and data presentation. We also gathered information on the type of residual limb problems typically encountered, how they currently manage those problems, and their ideas for methods to better manage them.Materials and methods: Two focus groups were held; one with certified prosthetists and another with lower-limb prosthesis users. Open-ended questions were used in a moderated discussion that was audio recorded, transcribed, and assessed using applied thematic analysis.Results and conclusions: Seven individuals participated in each focus group. Prosthetists came from a mix of practice settings, while prosthesis users were diverse in level of amputation, aetiology, and years of experience using lower-limb prostheses. Residual limb problems reported by participants were consistent with those in the literature. Participants suggested better managing residual limb problems through improved education, better detection of residual limb problems, and using sensor-based information to improve prosthetic technology. Participants favoured short-term use of a possible residual limb monitoring systems to troubleshoot residual limb problems, with temperature and pressure the most frequently mentioned measurements. Participants described that an ideal residual limb monitoring system would be lightweight, not interfere with prosthesis function, and result in benefits with regard to prosthetic care and socket function that outweighed inconveniences or concerns regarding system use. A potential positive of system use included having objective data for reimbursement justification, although it was pointed out that the residual limb monitoring system itself also needed to be reimbursable.Implications for RehabilitationStakeholders suggested better managing residual limb problems through improved education, better detection of residual limb problems, and using sensor-based information to improve prosthetic technology.Stakeholders favored short-term use of a possible system to troubleshoot residual limb problems, with temperature and pressure the most frequently mentioned measurements.Stakeholders described that an ideal residual limb monitoring system would be lightweight, not interfere with prosthesis function, and result in benefits with regard to prosthetic care and socket function that outweighs any inconveniences or concerns regarding system use.Stakeholders indicated that a potential positive of system use included having objective data for reimbursement justification, although it was pointed out that the residual limb monitoring system itself also needed to be reimbursable.

Characterization of Parylene-C degradation mechanisms: In vitro reactive accelerated aging model compared to multiyear in vivo implantation.

Implantable neural microelectrodes are integral components of neuroprosthetic technologies and can transform treatments for many neural-mediated disorders. However, dielectric material degradation during long-term (>1 year) indwelling periods restricts device functional lifetimes to a few years. This comprehensive work carefully investigates in vivo material degradation and also explores the ability of in vitro Reactive Accelerated Aging (RAA) to evaluate implant stability. Parylene C-coated Utah electrode arrays (UEAs) implanted in feline peripheral nerve for 3.25 years were explanted and compared to RAA-processed devices, aged in phosphate buffered saline (PBS) + 20 mM H2O2 at either 67 or 87 °C (28 or 7 days, respectively). Electron microscopy revealed similar physical damage characteristics between explants and RAA (87 °C) devices. Parylene C degradation was overwhelmingly apparent for UEAs from both RAA cohorts. Controls aged in PBS alone displayed almost no damage. Spectroscopic characterization (EDX, XPS, FTIR) found clear indications of oxidation and chlorine abstraction for Parylene C aged in vivo. While in vitro aging was also accompanied by signs of oxidation, changes in the chemistry in vivo and in vitro were statistically different. Analysis of RAA-aged devices identified UEA fabrication approaches that may greatly improve device resistance to degradation. This work underscores the need for an improved understanding of in vivo damage mechanisms, to facilitate the critical need for representative in vitro accelerated testing paradigms for long-term implants.

Wireless sensors for continuous, multimodal measurements at the skin interface with lower limb prostheses.

Precise form-fitting of prosthetic sockets is important for the comfort and well-being of persons with limb amputations. Capabilities for continuous monitoring of pressure and temperature at the skin-prosthesis interface can be valuable in the fitting process and in monitoring for the development of dangerous regions of increased pressure and temperature as limb volume changes during daily activities. Conventional pressure transducers and temperature sensors cannot provide comfortable, irritation-free measurements because of their relatively rigid construction and requirements for wired interfaces to external data acquisition hardware. Here, we introduce a millimeter-scale pressure sensor that adopts a soft, three-dimensional design that integrates into a thin, flexible battery-free, wireless platform with a built-in temperature sensor to allow operation in a noninvasive, imperceptible fashion directly at the skin-prosthesis interface. The sensor system mounts on the surface of the skin of the residual limb, in single or multiple locations of interest. A wireless reader module attached to the outside of the prosthetic socket wirelessly provides power to the sensor and wirelessly receives data from it, for continuous long-range transmission to a standard consumer electronic device such as a smartphone or tablet computer. Characterization of both the sensor and the system, together with theoretical analysis of the key responses, illustrates linear, accurate responses and the ability to address the entire range of relevant pressures and to capture skin temperature accurately, both in a continuous mode. Clinical application in two prosthesis users demonstrates the functionality and feasibility of this soft, wireless system.

Technique modifications for a suction suspension version of the Northwestern University Flexible Sub-Ischial Vacuum socket: The Northwestern University Flexible Sub-Ischial Suction socket.

BACKGROUND AND AIM:: Development of a passive suction version of the Northwestern University Flexible Sub-Ischial Vacuum socket would expand application of sub-ischial sockets to a larger proportion of persons with transfemoral amputation. While active vacuum suspension provides more positive coupling of the residual limb to the prosthetic socket, there are circumstances when use of active vacuum is not appropriate or feasible. Therefore, this technical note describes the technique modifications required to cast, fabricate, and fit a passive suction version of the Northwestern University Flexible Sub-Ischial Vacuum socket (i.e. the Northwestern University Flexible Sub-Ischial Suction socket). TECHNIQUE:: Most technique modifications stem from the use of an internal seal with the Northwestern University Flexible Sub-Ischial Suction socket and the need to account for the greater relative motion occurring between the residual limb and socket with passive suction compared to active vacuum suspension. DISCUSSION:: Between January 2015 and March 2018, 266 Northwestern University Flexible Sub-Ischial Suction sockets were fit successfully using the described technique modifications. CLINICAL RELEVANCE: A passive suction version of the Northwestern University Flexible Sub-Ischial Vacuum socket-the Northwestern University Flexible Sub-Ischial Suction socket-broadens the application of sub-ischial sockets to a larger proportion of the population with transfemoral amputation.

Risk Factors Associated With a Noncontact Anterior Cruciate Ligament Injury to the Contralateral Knee After Unilateral Anterior Cruciate Ligament Injury in High School and College Female Athletes: A Prospective Study.

BACKGROUND: The incidence of contralateral anterior cruciate ligament (CACL) injuries after recovery from a first-time anterior cruciate ligament (ACL) disruption is high in women; however, little is known about the risk factors associated with this trauma. HYPOTHESIS: Patient characteristics, strength, anatomic alignment, and neuromuscular characteristics of the contralateral uninjured leg at the time of the first ACL trauma are associated with risk of subsequent CACL injury, and these risk factors are distinct from those for a first-time ACL injury. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Sixty-one women who suffered a first-time noncontact ACL injury while participating in high school or college sports and underwent measurement of potential risk factors on their contralateral limb soon after the initial ACL injury and before reconstruction were followed until either a CACL injury or an ACL graft injury occurred, or until the last date of contact. RESULTS: Follow-up information was available for 55 (90.0%) of the 61 athletes and 11 (20.0%) suffered a CACL injury. Younger age, decreased participation in sport before the first ACL disruption, decreased anterior stiffness of the contralateral knee, and increased hip anteversion were associated with increases in the risk of suffering a CACL injury. CONCLUSION: A portion of CACL injury risk factors were modifiable (time spent participating in sport and increasing anterior knee stiffness with bracing), while others were nonmodifiable (younger age and increased hip anteversion). The relationship between younger age at the time of an initial ACL injury and increased risk of subsequent CACL trauma may be explained by younger athletes having more years available to be exposed to at-risk activities compared with older athletes. A decrease of anterior stiffness of the knee is linked to decreased material properties and width of the ACL, and this may explain why some women are predisposed to bilateral ACL trauma while others only suffer the index injury. The risk factors for CACL injury are unique to women who suffer bilateral ACL trauma compared with those who suffer unilateral ACL trauma. This information is important for the identification of athletes who may benefit from risk reduction interventions.

Change in residual limb size over time in the NU-FlexSIV socket: A case study.

BACKGROUND:: This case study represented a unique opportunity wherein a long-time user of sub-ischial sockets had kept nearly every socket he wore for a decade. This individual let us borrow these sockets so we could digitize them and indirectly assess change in residual limb size over time by calculating changes in socket volume and circumferences over time. CASE DESCRIPTION AND METHODS:: Over a decade, the subject maintained a relatively stable body weight of 84-88 kg and received nine sub-ischial sockets. The internal surface of each socket was scanned using a mechanical digitizer and volume and circumferences calculated. FINDINGS AND OUTCOMES:: Socket volume increased 31.3%, from a low of 2659.2 cm3 for the oldest socket to a high of 3490.6 cm3 for the most recent socket. Proximal circumferences increased more than distal circumferences with a 15.9% total increase proximally versus 8.9% total increase distally. DISCUSSION AND CONCLUSION:: The results suggest that this individual's residual limb increased in size over time despite the compressive effect of the socket and liner. In addition, the increase in circumference was greater proximally than distally, which is where the remaining muscle bellies are located. CLINICAL RELEVANCE: This case study provides insight into the long-term effect of the sub-ischial socket on residual limb volume given compression of the soft tissues by the socket system.

Neural electrode resilience against dielectric damage may be improved by use of highly doped silicon as a conductive material.

BACKGROUND: Dielectric damage occurring in vivo to neural electrodes, leading to conductive material exposure and impedance reduction over time, limits the functional lifetime and clinical viability of neuroprosthetics. We used silicon micromachined Utah Electrode Arrays (UEAs) with iridium oxide (IrOx) tip metallization and parylene C dielectric encapsulation to understand the factors affecting device resilience and drive improvements. NEW METHOD: In vitro impedance measurements and finite element analyses were conducted to evaluate how exposed surface area of silicon and IrOx affect UEA properties. Through an aggressive in vitro reactive accelerated aging (RAA) protocol, in vivo parylene degradation was simulated on UEAs to explore agreement with our models. Electrochemical properties of silicon and other common electrode materials were compared to help inform material choice in future neural electrode designs. RESULTS: Exposure of silicon on UEAs was found to primarily affect impedance at frequencies >1kHz, while characteristics at 1 kHz and below were largely unchanged. Post-RAA impedance reduction of UEAs was mitigated in cases where dielectric damage was more likely to expose silicon instead of IrOx. Silicon was found to have a per-area electrochemical impedance >10×higher than many common electrode materials regardless of doping level and resistivity, making it best suited for use as a low-shunting conductor. COMPARISON WITH EXISTING METHODS: Non-semiconductor electrode materials commonly used in neural electrode design are more susceptible to shunting neural interface signals through dielectric defects, compared to highly doped silicon. CONCLUSION: Strategic use of silicon and similar materials may increase neural electrode robustness against encapsulation failures.

Northwestern University Flexible Subischial Vacuum Socket for persons with transfemoral amputation-Part 1: Description of technique.

BACKGROUND: Current transfemoral prosthetic sockets restrict function, lack comfort, and cause residual limb problems. Lower proximal trim lines are an appealing way to address this problem. Development of a more comfortable and possibly functional subischial socket may contribute to improving quality of life of persons with transfemoral amputation. OBJECTIVES: The purpose of this study was to (1) describe the design and fabrication of a new subischial socket and (2) describe efforts to teach this technique. STUDY DESIGN: Development project. METHODS: Socket development involved defining the following: subject and liner selection, residual limb evaluation, casting, positive mold rectification, check socket fitting, definitive socket fabrication, and troubleshooting of socket fit. Three hands-on workshops to teach the socket were piloted and attended by 30 certified prosthetists and their patient models. RESULTS: Patient models responded positively to the comfort, range of motion, and stability of the new socket while prosthetists described the technique as "straight forward, reproducible." CONCLUSION: To our knowledge, this is the first attempt to create a teachable subischial socket, and while it appears promising, more definitive evaluation is needed. Clinical relevance We developed the Northwestern University Flexible Subischial Vacuum (NU-FlexSIV) Socket as a more comfortable alternative to current transfemoral sockets and demonstrated that it could be taught successfully to prosthetists.

Northwestern University Flexible Subischial Vacuum Socket for persons with transfemoral amputation: Part 2 Description and Preliminary evaluation.

BACKGROUND: Current transfemoral prosthetic sockets are problematic as they restrict function, lack comfort, and cause residual limb problems. Development of a subischial socket with lower proximal trim lines is an appealing way to address this problem and may contribute to improving quality of life of persons with transfemoral amputation. OBJECTIVES: The purpose of this study was to illustrate the use of a new subischial socket in two subjects. STUDY DESIGN: Case series. METHODS: Two unilateral transfemoral prosthesis users participated in preliminary socket evaluations comparing functional performance of the new subischial socket to ischial containment sockets. Testing included gait analysis, socket comfort score, and performance-based clinical outcome measures (Rapid-Sit-To-Stand, Four-Square-Step-Test, and Agility T-Test). RESULTS: For both subjects, comfort was better in the subischial socket, while gait and clinical outcomes were generally comparable between sockets. CONCLUSION: While these evaluations are promising regarding the ability to function in this new socket design, more definitive evaluation is needed. Clinical relevance Using gait analysis, socket comfort score and performance-based outcome measures, use of the Northwestern University Flexible Subischial Vaccum Socket was evaluated in two transfemoral prosthesis users. Socket comfort improved for both subjects with comparable function compared to ischial containment sockets.