Energy-Shunting Hip Padding System Attenuates Femoral Impact Force in a Simulated Fall

1995 ◽  
Vol 117 (4) ◽  
pp. 409-413 ◽  
Author(s):  
S. N. Robinovitch ◽  
W. C. Hayes ◽  
T. A. McMahon
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Impact Force ◽  
The Elderly ◽  
Impact Behavior ◽  
Human Female ◽  
Female Pelvis ◽  
The Mean ◽  
The Impact

Recent studies suggest that hip padding systems reduce the incidence of hip fractures during falls. However, no data exist on the force attenuating capacity of hip pads under realistic fall impact conditions, and thus it is difficult to compare the protective merit of various pad designs. Our goal is to design a comfortable hip padding system which reduces femoral impact force in a fall below the mean force required to fracture the elderly cadaveric femur. In pursuit of this objective, we designed and constructed a hip pad testing system consisting of an impact pendulum and surrogate human pelvis. We then developed a hip pad containing a shear-thickening material which allows for shunting of the impact energy away from the femur and into the surrounding soft tissue. Finally, we conducted experiments to assess whether the surrogate pelvis accurately represents the impact behavior of the human female pelvis in a fall, and to determine whether our energy-shunting pad attenuates femoral impact force in a fall more effectively than seven available padding systems. We found the surrogate pelvis accurately represented the human female pelvis in regional variation in soft tissue stiffness, total effective stiffness and damping, and impact force attenuation provided by trochanteric soft tissues. We also found that our padding system attenuated femoral impact force by 65 percent, thereby providing two times the force attenuation of the next best system. Moreover, the energy-shunting pad was the only system capable of lowering femoral impact force well below the mean force required to fracture the elderly femur in a fall loading configuration. These results suggest that the force attenuating potential of hip pads which focus on shunting energy away from the femur is superior to those which rely on absorbing energy in the pad material. While these in-vitro results are encouraging, carefully designed prospective clinical trials will be necessary to determine the efficacy of these approaches to hip fracture prevention.

scholarly journals The impact of COVID-19 infection on hip fracture 30-day mortality

Trauma ◽  
2021 ◽  
pp. 146040862094972
Author(s):  
Ahmed Fadulelmola ◽  
Rob Gregory ◽  
Gavin Gordon ◽  
Fiona Smith ◽  
Andrew Jennings
Keyword(s):  
Hip Fracture ◽  
Hip Fractures ◽  
Hospital Admissions ◽  
The Elderly ◽  
Primary Outcome Measure ◽  
Time To Death ◽  
Significant Difference ◽  
The Mean ◽  
The Impact ◽  
Mean Time

Introduction: A novel virus, SARS-CoV-2, has caused a fatal global pandemic which particularly affects the elderly and those with comorbidities. Hip fractures affect elderly populations, necessitate hospital admissions and place this group at particular risk from COVID-19 infection. This study investigates the effect of COVID-19 infection on 30-day hip fracture mortality. Method: Data related to 75 adult hip fractures admitted to two units during March and April 2020 were reviewed. The mean age was 83.5 years (range 65–98 years), and most (53, 70.7%) were women. The primary outcome measure was 30-day mortality associated with COVID-19 infection. Results: The COVID-19 infection rate was 26.7% (20 patients), with a significant difference in the 30-day mortality rate in the COVID-19-positive group (10/20, 50%) compared to the COVID-19-negative group (4/55, 7.3%), with mean time to death of 19.8 days (95% confidence interval: 17.0–22.5). The mean time from admission to surgery was 43.1 h and 38.3 h, in COVID-19-positive and COVID-19-negative groups, respectively. All COVID-19-positive patients had shown symptoms of fever and cough, and all 10 cases who died were hypoxic. Seven (35%) cases had radiological lung findings consistent of viral pneumonitis which resulted in mortality (70% of mortality). 30% ( n = 6) contracted the COVID-19 infection in the community, and 70% ( n = 14) developed symptoms after hospital admission. Conclusion: Hip fractures associated with COVID-19 infection have a high 30-day mortality. COVID-19 testing and chest X-ray for patients presenting with hip fractures help in early planning of high-risk surgeries and allow counselling of the patients and family using realistic prognosis.

scholarly journals Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Toni Wendler ◽  
Torsten Prietzel ◽  
Robert Möbius ◽  
Jean-Pierre Fischer ◽  
Andreas Roth ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Work Experience ◽  
Soft Tissues ◽  
Force Sensor ◽  
Biomechanical Study ◽  
Measuring System ◽  
Wide Range ◽  
Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

scholarly journals Do Prophylactic Knee Braces Protect the Knee Against Impacts or Tibial Moments? An In Vitro Multisensory Study

2018 ◽  
Vol 6 (11) ◽  
pp. 232596711880539 ◽  
Author(s):  
Steffen Paul Hacker ◽  
Florian Schall ◽  
Frank Niemeyer ◽  
Nicolas Wolf ◽  
Anita Ignatius ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Cruciate Ligament ◽  
Joint Line ◽  
Strain Change ◽  
Posterior Direction ◽  
Knee Braces ◽  
Anterior Cruciate ◽  
The Impact ◽  
Joint Acceleration

Background: Knee braces are prescribed by physicians to protect the knee from various loading conditions during sports or after surgery, even though the effect of bracing for various loading scenarios remains unclear. Purpose: To extensively investigate whether bracing protects the knee against impacts from the lateral, medial, anterior, or posterior directions at different heights as well as against tibial moments. Study Design: Controlled laboratory study. Methods: Eight limb specimens were exposed to (1) subcritical impacts from the medial, lateral, anterior, and posterior directions at 3 heights (center of the joint line and 100 mm inferior and superior) and (2) internal/external torques. Using a prophylactic brace, both scenarios were conducted under braced and unbraced conditions with moderate muscle loads and intact soft tissue. The change in anterior cruciate ligament (ACL) strain, joint acceleration in the tibial and femoral bones (for impacts only), and joint kinematics were recorded and analyzed. Results: Bracing reduced joint acceleration for medial and lateral center impacts. The ACL strain change was decreased for medial superior impacts and increased for anterior inferior impacts. Impacts from the posterior direction had substantially less effect on the ACL strain change and joint acceleration than anterior impacts. Bracing had no effect on the ACL strain change or kinematics under internal or external moments. Conclusion: Our results indicate that the effect of bracing during impacts depends on the direction and height of the impact and is partly positive, negative, or neutral and that soft tissue absorbs impact energy. An effect during internal or external torque was not detected. Clinical Relevance: Bracing in contact sports with many lateral or medial impacts might be beneficial, whereas athletes who play sports with rotational moments on the knee or anterior impacts may be safer without a brace.

scholarly journals Redefining Knee Balance in a Medially Stabilized Prosthesis: An In-Vitro Study

2017 ◽  
Vol 11 (1) ◽  
pp. 1165-1172
Author(s):  
Philippe Van Overschelde ◽  
Vera Pinskerova ◽  
Peter P. Koch ◽  
Christophe Fornasieri ◽  
Sandro Fucentese
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
In Vitro Study ◽  
Lateral Release ◽  
Soft Tissue Release ◽  
Iliotibial Band ◽  
Soft Tissue Envelope ◽  
Medial Side ◽  
Fresh Frozen

Background: To date, there is still no consensus on what soft tissues must be preserved and what structures can be safely released during total knee arthroplasty (TKA) with a medially stabilized implant. Objective: The aim of this study was to analyze the effect of a progressive selective release of the medial and lateral soft tissues in a knee implanted with a medially stabilized prosthesis. Method: Six cadaveric fresh-frozen full leg specimens were tested. In each case, kinematic pattern and mediolateral laxity were measured in three stages: firstly, prior to implantation; secondly, after the implantation of the trial components, but before any soft tissue release; and thirdly, progressively as soft tissue was released with the trial implant in place. The incremental impact of each selective release on knee balance was then analyzed. Results: In all cases sagittal stability was not affected by the progressive release of the lateral soft tissue envelope. It was possible to perform progressive lateral release provided the anterior one-third of the iliotibial band (ITB) remained intact. Progressive medial release could be performed on the medial side provided the anterior fibers of the superficial medial collateral ligament (sMCL) remained intact. Conclusion: The medially conforming implant remains stable provided the anterior fibers of sMCL and the anterior fibers of the ITB remain intact. The implant’s sagittal stability is mainly dependent on its medial ball-in-socket design.

scholarly journals Comparison of branded rugby headguards on their effectiveness in reducing impact on the head

2018 ◽  
Vol 4 (1) ◽  
pp. e000361 ◽  
Author(s):  
Erin R A Frizzell ◽  
Graham P Arnold ◽  
Weijie Wang ◽  
Rami J Abboud ◽  
Tim S Drew
Keyword(s):  
Impact Force ◽  
Linear Acceleration ◽  
Baseline Measurement ◽  
Peak Acceleration ◽  
Impact Forces ◽  
Impact Attenuation ◽  
The Mean ◽  
Force Reduction ◽  
The Right ◽  
The Impact

AimTo compare the available brands of rugby headguards and evaluate their impact attenuation properties at various locations on the cranium, with regard to concussion prevention.MethodsSeven different branded headguards were fitted onto a rigid headform and drop-tested in three different positions. An accelerometer measured the linear acceleration the headform experienced on impact with the ground. Each test involved dropping the headform from a height that generated 103.8 g on average when bare, which is the closest acceleration to the upper limit of the concussion threshold of 100 g. A mean peak acceleration for each drop position was calculated and compared with the bare baseline measurement.ResultsEach headguard demonstrated a significant decrease in the mean peak acceleration from the baseline value (all p≤0.01). Overall the Canterbury Ventilator was the most effective headguard, decreasing the impact force on average by 47%. The least effective was the XBlades Elite headguard, averaging a force reduction of 27%. In five of the seven headguards, the right side of the headwear was the most effective at reducing impact force.ConclusionOverall, the results indicate that it would be beneficial to wear a headguard during rugby in order to reduce the impact forces involved in head collisions. There was also a clear difference in performance between the tested brands, establishing the Canterbury headguard as the most effective. However, only one model of headguard from each brand was tested, so further research evaluating all other models should be considered.

A Quantitative Three-Dimensional Assessment of Abnormal Variations in Facial Soft Tissues of Adult Patients with Cleft Lip and Palate

2003 ◽  
Vol 40 (5) ◽  
pp. 544-549 ◽  
Author(s):  
Virgilio F. Ferrario ◽  
Chiarella Sforza ◽  
Claudia Dellavia ◽  
Gianluca M. Tartaglia ◽  
Davide Sozzi ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Cleft Lip ◽  
Soft Tissues ◽  
Cleft Lip And Palate ◽  
Three Dimensional ◽  
Z Score ◽  
Soft Tissue Profile ◽  
Variability Index ◽  
The Mean ◽  
Facial Soft Tissues

Objective To supply quantitative information about the facial soft tissues of adult operated patients with cleft lip and palate (CLP). Design, Setting, and Patients The three-dimensional coordinates of soft tissue facial landmarks were obtained using an electromagnetic digitizer in 18 Caucasian patients with CLP (11 males and 7 females aged 19 to 27 years) and 162 healthy controls (73 females and 89 males aged 18 to 30 years). From the landmarks, 15 facial dimensions and two angles were calculated. Data were compared with those collected in healthy individuals by computing z-scores. Two summary anthropometric measurements for quantifying craniofacial variations were assessed in both the patients and reference subjects: the mean z-score (an index of overall facial size), and its SD, called the craniofacial variability index (an index of facial harmony). Results In treated patients with CLP, facial size was somewhat smaller than in normal individuals, but in all occasions the mean z-score fell inside the normal interval (mean ± 2 SD). Almost all patients had a craniofacial variability index larger than the normal interval, indicating a global disharmonious appearance. Overall, in patients pronasale, subnasale, and pogonion were more posterior, the nose was shorter and larger, the face was narrower, and the soft tissue profile and upper lip were flatter than in the reference population. Conclusions The facial soft tissue structures of adult operated patients with CLP differed from those of normal controls of the same age, sex, and ethnic group. In this patient group, surgical corrections of CLP failed to provide a completely harmonious appearance, even if the deviations from the reference were limited. Further analyses of larger groups of patients are needed.

scholarly journals Comparison of the effect of collagen (amino acid) and amnion (proteinase inhibitor) on the wound healing of soft tissues

2010 ◽  
Vol 22 (1) ◽  
Author(s):  
Weko Adhiarto ◽  
Sunardhi Mangundjaja ◽  
Makmuri Yusuf ◽  
Bambang Pontjo
Keyword(s):  
Wound Healing ◽  
Amino Acid ◽  
Soft Tissue ◽  
Collagen Synthesis ◽  
Soft Tissues ◽  
Proteinase Inhibitors ◽  
Healing Process ◽  
Control Group ◽  
Wound Healing Process ◽  
The Mean

The wound healing process of the soft tissue aims to accelerate the closing of the wound by recurring, restoring the function, and minimizing the scar tissue. This process has to occur in the surgery process to obtain better-wound healing. The aim of this study was to know the stimulation effect of the wound dressing to accelerate the wound healing process of the soft tissue using Collagen (amino acid) and Amnion (proteinase inhibitors). This true experimental study was done to 36 mice (Sprague Dawley) that were divided into three different groups, two groups were the treatment groups and one group was the control group. Each group was adapted in Pathology Laboratory of Faculty of Veterinary Medicine Bogor Agricultural University. All of the mice were injured on the skin by incising the right side of the back for 2 cm in length and 4 mm in depth and then cleaned with 0.9% NaCl solution. To the first group of treatment, the wound was applicated by Amnion, and the second group was applicated by Collagen. Each 4 mice of all group were a termination by ether and encryption on the wounded tissue was conducted on day 3rd, 7th, and 14th. Assessment for a number of fibroblast and collagen synthesis on the wound of back tissue was conducted with the histological examination by painted using hematoxylin-eosin. The results concluded that Collagen application was influencing the mean of fibroblast higher than Amnion, and the lowest was controlled with statistically significant. The mean of collagen used Collagen lower than Amnion, and the lowest was control with statistically significant. It could be concluded that collagen application was preeminent in increasing the productivity of the fibroblast, as well as in developing forms of the collagen synthesis compared with Amnion and control.

scholarly journals SAT-434 Phenotype and Genotype Analysis of Patients with Resistance to Thyroid Hormone β: A Single-Center Experience

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Karn Wejaphikul ◽  
Prapai Dejkhamron ◽  
Stefan Groeneweg ◽  
W Edward Visser ◽  
Kevalee Unachak ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Mutation Analysis ◽  
Novel Mutation ◽  
Family Members ◽  
Antithyroid Drugs ◽  
Thyroid Function Tests ◽  
Resistance To Thyroid Hormone ◽  
The Mean ◽  
The Impact

Abstract Introduction Resistance to thyroid hormone β (RTHβ) is caused by mutations in THRB, the gene that encodes thyroid hormone receptor β. The clinical phenotype is variable and may include goiter, tachycardia, and learning disability with or without hyperactive behavior. The biochemical hallmark of RTHβ is elevated T4 and T3 with non-suppressed TSH concentrations. We here describe the phenotype and genotype of three Thai patients diagnosed with RTHβ in a pediatric referral center. Patients had previously been misdiagnosed and inappropriately treated with antithyroid drugs (ATDs). Methods Clinical features and thyroid function tests (TFTs) of three unrelated RTHβ patients were retrospectively reviewed. Genomic DNA of the RTHβ patients and affected family members was amplified for exon 7-10 of the THRB gene and sequenced to identify mutation by Sanger sequencing. The impact of the p.L341V novel mutation on the affinity for T3 and T3-induced transcriptional activity was previously determined in vitro. Results Three female patients were diagnosed with RTHβ. All of them had been misdiagnosed with hyperthyroidism and treated with ATDs prior to referral. The mean age at diagnosis was 8 years. The main presenting symptoms were diffuse goiter and tachycardia. The mean duration of ATD treatment was 3 years. During the treatment, patients had fluctuating thyroid hormone and increased TSH levels. An older sister and mother of one patient also had similar TFTs abnormalities, for which the mother had undergone a subtotal thyroidectomy. RTHβ was diagnosed based on the high FT3 and FT4 with normal (non-suppressed) TSH concentrations and confirmed by mutation analysis. Anti-thyroid peroxidase, anti-thyroglobulin, and TSH receptor antibody (TRAb) were negative, excluding autoimmune thyroid disease. Heterozygous missense mutations of the THRB gene were identified in all patients and affected family members. Two mutations had been previously reported (p.R243W and p.L456F), and one mutation was novel (p.L341V). In vitro studies confirmed an important role of Leu341 in T3 binding of the TRβ and functional impairment of the p.L341V novel mutation and were reported separately. According to available literature, only nine Thai RTHβ patients (in three families) carrying three different mutations (p.G251V, p.M313T, and p.A317T) had been previously reported. Goiter was the most common clinical finding, and almost all patients had a history of receiving unnecessary treatment with ATDs. Conclusion We report a series of RTHβ patients carrying THRB gene mutations, including one novel mutation (p.L341V). Clinicians should be alert that RTHβ can be found in patients with goiter and tachycardia. Elevated T4 and T3 with non-suppressed TSH concentration is the main diagnostic clue for this disease. Mutation analysis allows definitive diagnosis of RTHβ and may help to avoid potential misdiagnosis and improper treatment.

scholarly journals Aging predisposes to acute inflammatory induced pathology after tumor immunotherapy

2013 ◽  
Vol 210 (11) ◽  
pp. 2223-2237 ◽  
Author(s):  
Myriam N. Bouchlaka ◽  
Gail D. Sckisel ◽  
Mingyi Chen ◽  
Annie Mirsoian ◽  
Anthony E. Zamora ◽  
...  
Keyword(s):  
Critical Role ◽  
The Elderly ◽  
Mouse Tumor ◽  
Aged Mice ◽  
Liver Histopathology ◽  
Multiple Organs ◽  
The Impact ◽  
Young Mice

Cancer commonly occurs in the elderly and immunotherapy (IT) is being increasingly applied to this population. However, the majority of preclinical mouse tumor models assessing potential efficacy and toxicities of therapeutics use young mice. We assessed the impact of age on responses to systemic immune stimulation. In contrast to young mice, systemic cancer IT regimens or LPS given to aged mice resulted in rapid and lethal toxicities affecting multiple organs correlating with heightened proinflammatory cytokines systemically and within the parenchymal tissues. This inflammatory response and increased morbidity with age was independent of T cells or NK cells. However, prior in vivo depletion of macrophages in aged mice resulted in lesser cytokine levels, increased survival, and decreased liver histopathology. Furthermore, macrophages from aged mice and normal human elderly volunteers displayed heightened TNF and IL-6 production upon in vitro stimulation. Treatment of both TNF knockout mice and in vivo TNF blockade in aged mice resulted in significant increases in survival and lessened pathology. Importantly, TNF blockade in tumor-bearing, aged mice receiving IT displayed significant anti-tumor effects. These data demonstrate the critical role of macrophages in the age-associated hyper-inflammatory cytokine responses to systemic immunostimulation and underscore the importance of performing preclinical assessments in aged mice.

scholarly journals Development and Qualification of a Pharmacodynamic Model for the Pronounced Inoculum Effect of Ceftazidime against Pseudomonas aeruginosa

2008 ◽  
Vol 53 (1) ◽  
pp. 46-56 ◽  
Author(s):  
Jürgen B. Bulitta ◽  
Neang S. Ly ◽  
Jenny C. Yang ◽  
Alan Forrest ◽  
William J. Jusko ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Predictive Performance ◽  
Pkpd Model ◽  
Infection Models ◽  
The Mean ◽  
Inoculum Effect ◽  
Successful Replication ◽  
Time Kill ◽  
The Impact

ABSTRACT Evidence is mounting in support of the inoculum effect (i.e., slow killing at large initial inocula [CFUo]) for numerous antimicrobials against a variety of pathogens. Our objectives were to (i) determine the impact of the CFUo of Pseudomonas aeruginosa on ceftazidime activity and (ii) to develop and validate a pharmacokinetic/pharmacodynamic (PKPD) mathematical model accommodating a range of CFUo. Time-kill experiments using ceftazidime at seven concentrations up to 128 mg/liter (MIC, 2 mg/liter) were performed in duplicate against P. aeruginosa PAO1 at five CFUo from 105 to 109 CFU/ml. Samples were collected over 24 h and fit by candidate models in NONMEM VI and S-ADAPT 1.55 (all data were comodeled). External model qualification integrated data from eight previously published studies. Ceftazidime displayed approximately 3 to 4 log10 CFU/ml net killing at 106.2 CFUo and concentrations of 4 mg/liter (or higher), less than 1.6 log10 CFU/ml killing at 107.3 CFUo, and no killing at 108.0 CFUo for concentrations up to 128 mg/liter. The proposed mechanism-based model successfully described the inoculum effect and the concentration-independent lag time of killing. The mean generation time was 28.3 min. The effect of an autolysin was assumed to inhibit successful replication. Ceftazidime concentrations of 0.294 mg/liter stimulated the autolysin effect by 50%. The model was predictive in the internal cross-validation and had excellent in silico predictive performance for published studies of P. aeruginosa ATCC 27853 for various CFUo. The proposed PKPD model successfully described and predicted the pronounced inoculum effect of ceftazidime in vitro and integrated data from eight literature studies to support translation from time-kill experiments to in vitro infection models.

Sign in / Sign up

Export Citation Format

Share Document