Normal Joint Research Articles

Effectiveness of Maximum Voluntary Contraction Using Surface Electromyography on Erector Spinae and Tensor Fascia Latae Muscle Along With Muscle Energy Technique in Chronic Non-Specific Low Back Pain

Background: Low Back Pain (LBP) one of the major health issues over the world. It affects quality of life and work absentness leads to disability. Non-specific Low Back Pain (NSLBP) does not have specified problem. In this type, muscle imbalance, distributed muscle strength, endurance, movement co-ordination impairment, poor posture might enhance the nociceptor stimuli.Muscle energy technique (MET) is an active manual technique focused over muscle stretching, strengthening, relaxing. Aims to restore normal joint mobility and reduce pain.Aim: To determine the effect of muscle energy technique in chronic non-specific low back pain.To study the effectiveness of muscle energy technique in subjects with chronic non-specific low back pain on pain, functional disability and Surface electromyography (SEMG) measures.Material and Method: A total of 40 subjects were included in the study. 20 subjects with CNSLBP were allocated in a group A. whereas group B was allocated with Core Muscle Strengthening exercises (CMSE) for three weeks. All the participants were clearly explained about the procedure and informed consent attained.In group A, MET was applied over four muscle groups namely quadratus Lumborum (QL), erector spinae (ES), iliopsoas, tensor fascia latae (TFL). SEMG study was done over the two muscles, ES and TFL. At rest period measurement was done after their maximum voluntary contraction was recorded. Results: Pre-post-test comparison was analysed by Wilcoxon’s matched pair test. Between group analysis done by Mann Whitney U test, the experimental groups exhibit VAS, ODI, SEMG-ES (Rt and Lt), TFL (t and Lt) shown significance at p value = 0.001. Conclusion: MET was effectively reducing functional disability, decreases pain, muscle strength improved in ES and TFL muscles of both sides evaluated through SEMG.

Estimating elbow loading conditions through the motion behaviors of subchondral bone density during joint movements

Evaluating complicated stress across the elbow under joint motion remains difficult. Here, we aimed to evaluate the distribution of the subchondral bone density in the normal elbow bones and further characterize their spatial relationships during elbow motion to estimate the loading stress across the articular surface using three-dimensional computed tomography bone models. The normal elbow joint exhibited a consistent distribution pattern of subchondral bone density. High-density regions were distributed in the capitellum and posterior humeral trochlea, sagittal ridge of the ulnar trochlear notch and ulnar-volar side of the radial head. Motion analyses revealed that the high-density regions proximate with elbow flexion with forearm pronation in the radiocapitellar joint and in the fully extended position in the ulnohumeral joint. This reasonably reflects the stress acting on the joint surface under actual loading conditions. These findings suggest that daily activities involving lifting or carrying objects in these positions are stress-prone activities.

Association between temporomandibular joint dysfunction signs and symptoms, mental health indices, and MRI diagnoses: should we scan patients?

Temporomandibular joint dysfunction (TMD) is a common condition; yet multifactorial in nature. Our understanding of the interplay between clinical symptoms in relation to Magnetic resonance imaging (MRI) findings and quality of life is limited. Our primary objective was to identify features of TMD contributing to anxiety and depression. Our secondary objective was to determine whether clinical symptoms, baseline characteristics, and mental health outcomes are associated with underlying disease severity, as determined by MRI. A retrospective analysis of 202 TMD patients was performed. Mental health outcomes were quantified using the IMPARTS psychometric questionnaire (Visual Analog Score, VAS; Generalised Anxiety Disorder Assessment, GAD7;, Patient Health Questionnaire, PHQ-9), and patients were categorised based on temporomandibular joint pathology severity (normal, anterior disc displacement with reduction, anterior disc displacement without reduction and severe degeneration). On multivariable analyses, both higher anxiety (p<0.001) and depression (p<0.001) scores on IMPARTS assessment were associated with worst perceived pain (on VAS). Unilateral joint involvement (OR2.48[95%CI 1.20;5.46],p=0.018), locking (OR4.28[95%CI 1.63;13.63],p=0.006) , and clicking (OR2.14[95%CI1.05;4.60],p=0.006) were significantly associated with increased odds of an abnormal TMJ on MRI, whereas higher anxiety scores (OR0.93[95%CI 0.88;0.99],p=0.006) and male gender (OR0.35[95%CI 0.15;0.79],p=0.012) were significantly predictive of a normal joint morphology on MRI. Our findings support a complex interplay between patient symptomology, mental health outcomes and objective radiologically-defined joint pathology in the TMD patient population.

Relationship between the Articular Cartilage Thickness of the Patella and Trochlea in Trochlear Dysplasia Compared to Normal Knees

Abstract Introduction: Anterior knee pain is not an uncommon problem. A plethora of pathologies can cause anterior knee pain. Patellofemoral maltracking (trochlear dysplasia) is not an uncommon cause of anterior knee pain in adolescents and young adults. Aim: We hypothesize that there is an alteration of articular cartilage of the patella and trochlear in trochlear dysplasia. Materials and Methods: Magnetic resonance images of 86 knee joints were reviewed independently by two musculoskeletal radiologists. Standard magnetic resonance imaging (MRI) sequences were used in this study. Based on the Dejour classification for trochlear dysplasia, the patients were divided into normal, Type A, B, C, and D. The articular cartilage thickness of the patella and trochlea was measured and compared between the groups. Results: Out of the 86 MRI scans of the knees which were reviewed, 32 patients were male and 54 were female. The mean patient age was 21.9 years (range = 10–40). Sixty-six knee joints had trochlear dysplasia, with 15 patients classified into Dejour Type A, 13 in Type B, 31 in Type C, and 7 in Type D. There was no significant difference in the articular cartilage thickness of the lateral facet of the patella between all groups (ANOVA F = 1.43, P = 0.23). Conclusion: There was no significant difference in the articular cartilage thickness in the lateral facet of the patella and trochlea in patients with normal knee joints compared to those with trochlear dysplasia of Type A–D.

Characterization of the single cell landscape in normal and osteoarthritic equine joints.

Osteoarthritis (OA) is a major source of pain and disability worldwide. Understanding of disease progression is evolving, but OA is increasingly thought to be a multifactorial disease in which the innate immune system plays a role in regulating and perpetuating low-grade inflammation. The aim of this study was to enhance our understanding of OA immunopathogenesis through characterization of the transcriptomic responses in OA joints, with the goal to facilitate the development of targeted therapies. Single-cell RNA sequencing (scRNA-seq) was completed on cells isolated from the synovial fluid of three normal and three OA equine joints. In addition to synovial fluid, scRNA-seq was also performed on synovium from one normal joint and one OA joint. Characterization of 28,639 cells isolated from normal and OA-affected equine synovial fluid revealed the composition to be entirely immune cells (CD45+) with 8 major populations and 26 subpopulations identified. In synovial fluid, we found myeloid cells (macrophage and dendritic cells) to be overrepresented and T cells (CD4 and CD8) to be underrepresented in OA relative to normal joints. Through subcluster and differential abundance analysis of T cells we further identified a relative overrepresentation of IL23R+ gamma-delta (γδ) T cells in OA-affected joints (a cell type we report to be enriched in gene signatures associated with T helper 17 mediated immunity). Analysis of an additional 17,690 cells (11 distinct cell type clusters) obtained from synovium of one horse led to the identification of an OA-associated reduction in the relative abundance of synovial macrophages, which contrasts with the increased relative abundance of macrophages in synovial fluid. Completion of cell-cell interaction analysis implicated myeloid cells in disease progression, suggesting that the myeloid-myeloid interactions were increased in OA-affected joints. Overall, this work provides key insights into the composition of equine synovial fluid and synovium in health and OA. The data generated in this study provides equine-specific cell type gene signatures which can be applied to future investigations. Furthermore, our analysis highlights the potential role of macrophages and IL23R+ γδ T cells in OA immunopathogenesis.

A Computer Modeling-Based Target Zone for Transposition Osteotomy of the Acetabulum in Patients with Hip Dysplasia.

This study aimed to determine the acetabular position to optimize hip biomechanics after transposition osteotomy of the acetabulum (TOA), a specific form of periacetabular osteotomy, in patients with hip dysplasia. We created patient-specific finite-element models of 46 patients with hip dysplasia to simulate 12 virtual TOA scenarios: lateral rotation to achieve a lateral center-edge angle (LCEA) of 30°, 35°, and 40° combined with anterior rotation of 0°, 5°, 10°, and 15°. Joint contact pressure (CP) on the acetabular cartilage during a single-leg stance and simulated hip range of motion without osseous impingement were calculated. The optimal acetabular position was defined as satisfying both normal joint CP and the required range of motion for activities of daily living. Multivariable logistic regression analysis was used to identify preoperative morphological predictors of osseous impingement after virtual TOA with adequate acetabular correction. The prevalence of hips in the optimal position was highest (65.2%) at an LCEA of 30°, regardless of the amount of anterior rotation. While the acetabular position minimizing peak CP varied among patients, approximately 80% exhibited normalized peak CP at an LCEA of 30° and 35° with 15° of anterior rotation, which were the 2 most favorable configurations among the 12 simulated scenarios. In this context, the preoperative head-neck offset ratio (HNOR) at the 1:30 clock position (p = 0.018) was an independent predictor of postoperative osseous impingement within the required range of motion. Specifically, an HNOR of <0.14 at the 1:30 clock position predicted limitation of required range of motion after virtual TOA (sensitivity, 57%; specificity, 81%; and area under the receiver operating characteristic curve, 0.70). Acetabular reorientation to an LCEA of between 30° and 35° with an additional 15° of anterior rotation may serve as a biomechanics-based target zone for surgeons performing TOA in most patients with hip dysplasia. However, patients with a reduced HNOR at the 1:30 clock position may experience limited range of motion in activities of daily living postoperatively. This study provides a biomechanics-based target for refining acetabular reorientation strategies during TOA while considering morphological factors that may limit the required range of motion.

Enhanced stability of the distal radioulnar joint with double suture button construct: a cadaveric study

BackgroundDistal radioulnar joint (DRUJ) instability is a common post-traumatic complication, often leading to chronic pain and dysfunction. Current reconstructive techniques, such as the single suture button construct, offer suboptimal stabilization in certain motions. This study aimed to evaluate whether a double suture button construct provides greater stability than the single construct in a cadaver model of DRUJ instability. We hypothesized that the double suture button construct would more effectively minimize dorsal translation of the radius relative to the ulna.MethodsWe used nine freshly frozen human cadaver upper extremities, destabilized the DRUJ, and then reconstructed the joint using three different suture button constructs: single transverse, double (transverse + oblique), and single oblique. The specimens were secured in a custom-designed testing apparatus to measure dorsal translation of the radius. The study proceeded in five stages: stable DRUJ, unstable DRUJ, and reconstruction using a single transverse, double (transverse + oblique), and single oblique suture button construct. Dorsal translation was measured at neutral, 45° pronation, and 45° supination. Statistical comparisons of mean values were conducted for each stage.ResultsReconstruction with the transverse, transverse plus oblique, and oblique suture button constructs resulted in statistically significant reductions in dorsal translation compared to the unstable DRUJ (p < 0.001 for all). The double-suture button construct significantly minimized dorsal translation in all positions, restoring stability comparable to a stable DRUJ: neutral (p = 1.000), pronation (p = 0.963), and supination (p = 1.000). In contrast, single constructs failed to fully restore stability in pronation and supination.ConclusionThe double suture button construct provides significantly greater stabilization of the DRUJ compared to the single construct. These findings suggest that the double construct could be a more effective option for treating DRUJ instability, particularly in restoring normal joint function during various motions. Further research is warranted to confirm these results in clinical settings.

Morphologic characteristics of temporomandibular joint on the patients with anterior disc displacement without osteoarthritis: a case-based research

We investigated the effect of anterior disc displacement without osteoarthritis (ADDwoOA) on the morphology of the temporomandibular joint (TMJ) utilizing three-dimensional (3D) models of 23 asymptomatic individuals and 30 ADDwoOA patients. Statistical analyses between the groups were performed by measuring 10 morphological parameters. ADDwoOA patients showed significantly decreased levels of the sagittal ramus angle (SRA) and joint spaces compared with asymptomatic subjects. Moreover, the patients who had recovered exhibited normal joint spaces levels. Consequently, ADDwoOA caused the condyles to move backward and upward, approaching the articular fossa. Joint spaces can serve as an important observation during the treatment of ADD.

Disuse atrophy of articular cartilage can be restored by mechanical reloading in mice

BackgroundModerate mechanical stress generated by normal joint loading and movements helps maintain the health of articular cartilage. Despite growing interest in the pathogenesis of cartilage degeneration caused by reduced mechanical stress, its reversibility by mechanical reloading is less understood. This study aimed to investigate the response of articular cartilage exposed to mechanical reloading after unloading in vivo and in vitro.Methods and resultsDisuse atrophy was induced in the knee joint cartilage of adult mice through hindlimb unloading by tail suspension. For in vivo experiments, mice were subjected to reloading with or without daily exercise intervention or surgical destabilization of the knee joint. Microcomputed tomography and histomorphometric analyses were performed on the harvested knee joints. Matrix loss and thinning of articular cartilage due to unloading were fully or partially restored by reloading, and exercise intervention enhanced the restoration. Subchondral bone density decreased by unloading and increased to above-normal levels by reloading. The severity of cartilage damage caused by joint instability was not different even with prior non-weight bearing. For in vitro experiments, articular chondrocytes isolated from the healthy or unloaded joints of the mice were embedded in agarose gel. After dynamic compression loading, the expression levels of anabolic (Sox9, Col2a1, and Acan) and catabolic (Mmp13 and Adamts5) factors of cartilage were analyzed. In chondrocytes isolated from the unloaded joints, similar to those from healthy joints, dynamic compression increased the expression of anabolic factors but suppressed the expression of catabolic factors.ConclusionThe results of this study indicate that the morphological changes in articular cartilage exposed to mechanical unloading may be restored in response to mechanical reloading by shifting extracellular matrix metabolism in chondrocytes to anabolism.

Radiological and Anthropometrical Analysis of the Hip Joint Using Computed Tomography Scan in North Indian Population

Abstract Background: Anthropometric research on the hip joint has significant clinical implications, including (1) implant design and (2) avoiding implant mismatch complications, such as aseptic loosening and incorrect load distribution, which are mainly unknown in North India. The aim of this research is to ascertain the anatomical differences in the normal hip joint across individuals in North India and to statistically compare the results with global data. Materials and Methods: We used one hip topogram and one axial segment of the femoral head to analyze 100 people (35 females and 65 males) with normal hips between the ages of 20 and 65. In both sexes and on both sides, we determined the means of the following measurements: femoral head diameter (HD), femoral neck width (NW), femoral neck length, acetabular angle of sharp, femoral version, horizontal offset, acetabular version, and vertical offset. Results: The following are the mean parameters that were observed: (a) neck shaft angle (NSA) - 128.93°, (b) femoral HD = 4.29 cm, (c) femoral NW = 2.97 cm, (d) femoral neck length = 3.61 cm, (e) Acetabular angle of Sharp - 33.01°, (f) Acetabular version = 20.44°, (g) femoral Version = 21.57°, (h) horizontal offset = 3.62 cm, and (i) Vertical offset = 4.43 cm. Conclusion: The NSA and acetabular angle of sharp were 5°–6° more when compared to the western population while horizontal and vertical offset is comparatively less than Western population and in the Indian NSA was higher for North Eastern population than the North Indian population. The residual parameters were comparable to those found in Western literature.

A novel statistical damage constitutive model of rock joints considering normal stress and joint roughness

The shear constitutive model of rock joints is of great significance to the stability analysis in rock engineering, and it is closely related to the normal stress ([Formula: see text]) and joint roughness coefficient ( JRC). However, the existing investigations seldom consider the influences of [Formula: see text] and JRC simultaneously. Therefore, a novel damage constitutive model considering the [Formula: see text] and JRC is developed in this work. In the presented model, it is assumed that the rock materials are composed of damaged and undamaged microunits, and the damage evolution law of the microunits conforms to the Weibull distribution in the shear process. Based on the proposed assumption, the constitutive relationship between shear stress and shear displacement is deduced. The evolutions of the mechanical parameters and damage variable versus [Formula: see text] and JRC are analyzed in detail. The proposed damage model that involves [Formula: see text] and JRC is verified by comparing theoretical values with the laboratory results. The results show that the damage constitutive model is in good agreement with the test results. Additionally, the influences of [Formula: see text] and JRC on the shear stress-displacement curves are studied. This work can provide a valuable theoretical method for analyzing the shear mechanical characteristics and damage evolution laws of rock joints.

Relationship between Feline Knee Joint Osteoarthritis and Bone Mineral Density Quantified Using Computed Tomography and Computed Digital Absorptiometry.

Osteoarthritis (OA), including knee joint OA, is a common chronic condition in cats. In both cats and humans, knee joint OA is characterized radiographically by the presence of osteophytes, enthesiophytes, subchondral sclerosis, and joint space narrowing. However, only in humans have these radiographic signs been reported to increase bone mineral density (BMD). Therefore, this study aims to quantify the volumetric (vBMD) and relative (rBMD) BMD measures of the feline knee joint and compare BMD measures between various severities of OA to test the hypothesized OA-BMD relationship in the knee joint in cats. The 46 feline knee joints were imaged using computed tomography (CT) and conventional radiography supported by the computed digital absorptiometry (CDA) method to obtain vBMD and rBMD, respectively. Both BMD measures were assessed in three regions of interest (ROIs): the distal femur (ROI 1), patella (ROI 2), and proximal tibia (ROI 3). In all locations, vBMD and rBMD showed moderate (ROI 2: r = 0.67, p < 0.0001) to strong (ROI 1: ρ = 0.96, p < 0.0001; ROI 3: r = 0.89, p < 0.0001) positive correlations. Due to differences (p < 0.0001) in the width of the distal femur (17.9 ± 1.21 mm), patella (8.2 ± 0.82 mm), and proximal tibia (19.3 ± 1.16 mm), the rBMD was corrected (corr rBMD) using the thickness coefficient of 0.46 ± 0.04 for ROI 2 and 1.08 ± 0.03 for ROI 3. Regardless of the quantification method used, BMD measures increased linearly from a normal knee joint to severe OA, with differences in BMD between normal and mild to severe knee joint OA. The OA-BMD relationship in the feline knee joint can be preliminarily confirmed.

Effect of Sclerosis Bands in Femoral Head Necrosis on Non-Vascularized Fibular Grafting-A Finite Element Study.

Femoral head necrosis is a challenging condition in orthopaedics, and the occurrence of collapse is an important factor affecting the prognosis of femoral head necrosis. Sclerosis bands are known to influence the collapse of the femoral head, yet there is a lack of research on the biomechanical role of sclerosis bands in non-vascularized fibular grafting surgery. This study aims to evaluate the biomechanical impact of sclerosis bands in femoral head necrosis and their role in non-vascularized fibular grafting surgery (NVFG) using finite element analysis. We constructed 11 finite element models based on CT scan data of a normal hip joint, simulating different sclerosis band thicknesses and defect scenarios. The models were analyzed for changes in femoral head displacement and von Mises stress. We constructed a hip joint model based on CT data from a normal hip joint, and after reconstruction, assembly, and optimization using 3-matic. We created five groups consisting of 11 finite element analysis models of the hip joint. Mesh partitioning and mechanical parameter settings were performed in ANSYS. The changes and differences in femoral head displacement and von Mises stress of these models were analyzed. Increasing sclerosis band thickness led to reduced peak displacement of the femoral head by 28.6%, 42.9%, and 47.6%, and increased surface von Mises stress by 28.3%, 13.8%, and 13.0%, respectively. Post-surgery, peak displacement decreased in all groups compared to pre-surgery levels. Increasing sclerosis band thickness post-surgery resulted in decreased maximum von Mises stress of the femoral head by 13.9%, 3.0%, and 8.1%. Defect volume in the defect groups correlated with increased peak displacement of the femoral head by 10.0%, 30.0%, and 100.0%, and increased surface maximum von Mises stress of the femoral head by 9.3%, 14.0%, and 15.1%. Sclerosis band formation exacerbates von Mises stress concentration on the femoral head surface. However, thicker sclerosis bands improve post-NVFG stability and mechanical performance. Larger anterior lateral sclerosis band defects significantly compromise postoperative stability, increasing the risk of collapse. Protecting the anterior lateral sclerosis band during NVFG surgery is crucial.

A Theoretical and Experimental Study on Asperity Damage-Driven Strain Rate Dependency of Fractured Coal

AbstractAsperities within pre-existing fractures of coals can experience local damage during the fracture closure due to external loading. Previous research postulates that this local asperity damage can lead to strain rate-dependency without causing permanent deformation to the bulk of the coal specimens. This study aims to comprehensively investigate this behavior by developing a theoretical model that characterizes the strain rate-dependency driven by fracture asperity damage in coal. To achieve this objective, an initial series of micro-scale mechanical tests are conducted on joint specimens to establish a model for effective stress acting on asperities. Building upon this model, a theoretical foundation is further developed to describe the strain rate-dependent asperity damage evolution and resulting energy dissipation. These frameworks are subsequently incorporated into elasticity and damage mechanics to capture the strain rate-dependent stress–strain relationships. To validate the proposed model across multiple scales, additional triaxial tests on core-scale specimen and micro-scale mechanical tests on joint specimens are performed. The experimentally measured strain rate-dependency aligns well with the predictions of the proposed model, indicating a successful development of a robust model. The results of the model developed in this study reveal that the strain rate-dependency in fractured coals is governed by several factors, including asperity damage, mechanical properties of the coal specimens and effective stress acting on asperities of pre-existing fractures within the bulk of coal. Moreover, it is shown that the effective stress acting on asperities is significantly affected by both applied normal stress and joint roughness coefficient (JRC). The insights derived from this study demonstrate that the strain rate-dependency induced by micro-scale asperity damage of pre-existing fractures leads to observable strain rate-dependency in bulk specimens at core-scale and the proposed model can adequately capture this behavior.

Microstructure and mechanical properties in electron beam scanning welded joints of super thick titanium alloy plates

It is generally difficult to obtain good weld formation and excellent properties in super thick titanium alloy joints via conventional electron beam welding (EBW) methods due to the fact that the melt pool flow becomes more unstable as the plate thickness increases. In this study, electron beam scanning welding (EBSW) was utilized to weld 100 mm Ti–6Al–3Nb–3Zr–1Mo titanium alloy plates to improve the weld formation and impact toughness through the scanning effect. The results revealed that there were spatter and cutting defects on the surface and inner pore defect in the normal EBW joint, which could be effectively eliminated via EBSW. The decrease of the amplitude of the fluid flow rate and the change of the velocity direction were mainly responsible for this. A large amount of lamellar α phase with similar orientation was formed in the fusion zone (FZ) due to the fast cooling rate. The joint coefficient for both EBSW and EBW reached 100%, with the joint tensile strength of ∼840 MPa. The impact energy of the FZ in the EBSW joint was 70.5 J, reaching 210.4% of that of the BM (33.5 J). The impact toughness increase ratio in this study was far larger than those for Ti alloy welds ever reported, which was mainly attributed to that the high angle α colony boundaries with high preferred orientation in the FZ deflected the crack propagation direction. This study provides a reference for the strength-toughness design of EBWed joints of super thick Ti6331 titanium alloy.

The Exosomes of Stem Cells from Human Exfoliated Deciduous Teeth Suppress Inflammation in Osteoarthritis.

Hyaluronic acid injection is commonly used clinically to slow down the development of osteoarthritis (OA). A newly developed therapeutic method is to implant chondrocytes/stem cells to regenerate cartilage in the body. The curative effect of stem cell therapy has been proven to come from the paracrine of stem cells. In this study, exosomes secreted by stem cells from human exfoliated deciduous teeth (SHED) and hyaluronic acid were used individually to evaluate the therapeutic effect in slowing down OA. SHED was cultured in a serum-free medium for three days, and the supernatant was collected and then centrifuged with a speed difference to obtain exosomes containing CD9 and CD63 markers, with an average particle size of 154.1 nm. SW1353 cells were stimulated with IL-1β to produce the inflammatory characteristics of OA and then treated with 40 μg/mL exosomes and hyaluronic acid individually. The results showed that the exosomes successfully inhibited the pro-inflammatory factors, including TNF-α, IL-6, iNOS, NO, COX-2 and PGE2, induced by IL-1β and the degrading enzyme of the extrachondral matrix (MMP-13). Collagen II and ACAN, the main components of the extrachondral matrix, were also increased by 1.76-fold and 2.98-fold, respectively, after treatment, which were similar to that of the normal joints. The effect can be attributed to the partial mediation of SHED exosomes to the NF-κB pathway, and the ability of exosomes to inhibit OA is found not inferior to that of hyaluronic acid.

Long head of the biceps tendon plays a role in stress absorption and humeral head restriction during the late cocking and deceleration phases of overhead throwing: a finite element study

BackgroundEmerging evidence suggests that the long head of the biceps (LHBT) may play a role in stabilizing the glenohumeral joint, and this has led to controversy around the efficacy of biceps tenotomy for superior labral anterior and posterior (SLAP) lesions. Therefore, the aim of this finite element analysis (FEA) study was to determine the stress absorption and humeral head translation restriction effects of the LHBT within the glenohumeral joint during the late cocking and deceleration phases of overhead throwing with a view to resolving the controversy around tenotomy. MethodsEight FEA models were created using computed tomography and magnetic resonance imaging data from normal glenohumeral joints. The models represented four LHBT conditions: uninjured, subpectoral tenodesis, tenotomy, and type II SLAP lesions. The late cocking and deceleration phases of the overhead throwing were simulated for each model. The impacts of the four LHBT conditions on glenohumeral joint stress absorption and humeral head displacement restriction were studied based on 1) stress and related distributions on the cartilage, labrum, capsule, and LHBT and 2) humeral head translation variation. ResultsThe FEA analysis showed that the magnitude of the contact stress on the articular cartilage, labrum, and capsule was the lowest in the uninjured models, followed by the subpectoral tenodesis, tenotomy, and type II SLAP lesion models. Humeral head translation was the most restricted in the subpectoral tenodesis models, followed by the tenotomy and type II SLAP lesion models. ConclusionFinite element analysis demonstrated that the LHBT plays a significant role in stress absorption and displacement restriction in the late cocking and deceleration phases of overhead throwing. Subpectoral tenodesis of the LHBT exhibited lesser amount of stress and humeral head translation than those of tenotomy, thereby making it a better option for patients who engage in overhead throwing.

Physical Impairment or Disability? Three Cases of Developmental Dysplasia of the Hip from Grote Kerk, Alkmaar, the Netherlands (A.D. 1716–1830)

Disability is part of the human experience, yet until recently, the lived experiences of individuals affected by physical impairment have been overlooked in bioarchaeological studies. Disability is a social construct; how we define disability is culturally specific, which makes identifying disability in archaeological contexts difficult. However, by defining disability as the inability to function within expected lifeways, it is possible to examine the effects of physical impairment on lived experiences and explore the construction of disability in historic contexts. Using a biocultural lens and robust cultural contextualization, this study examines the ability to function of three middle- to upper-class adult females from Grote Kerk, Alkmaar, the Netherlands (A.D. 1716–1830), with diagnoses of permanent, bilateral developmental dysplasia of the hip (DDH). DDH results from an abnormality in the hip joint’s size, shape, or orientation and, when untreated, leads to loss of normal joint function and deteriorating quality of life. While DDH probably resulted in limited mobility and pain for all three individuals analyzed in the present study, there is little evidence to support disablement in the form of social restrictions. The findings add to the ongoing discussion of historic disability by examining the intersection of socioeconomic status, sex, and physical impairment in a post-medieval Dutch population and add data that can be used in estimating historic prevalence rates of DDH, which are variable across modern populations.

Evaluation of cartilage properties from NIR diffuse reflectance spectra: numerical simulation

Diseased conditions of articular cartilage such as osteoarthritis (OA) are accompanied by a change in the water concentration, together with a decrease in cartilage thickness. These parameters are important indicators of the normal joint functioning. Light scattering in a heterogeneous joint tissue is a complex process and it is important to supplement its study with understanding gained from modelling. In this work we employed Monte Carlo for analysis of the relationship between changes in cartilage parameters and calculated diffuse reflectance spectra. It has been shown that water absorption peak at 980 nm is determined by both water content and cartilage thickness, while changes in diffuse reflectance spectra at 1450 nm are mostly driven only by water content. Since independent assessment of these parameters is clinically relevant, several approaches for their determination were developed. A heuristic algorithm for cartilage thickness determination and its quality metrics (R 2 = 0.96) were obtained. Several regression models were developed using the amplitudes of diffuse reflectance spectra at different wavelengths and it was shown that the use of a wide range of wavelengths (850–1700 nm) allows to determine the cartilage water concentration and its thickness with the accuracy R 2 0.96 and 0.99 while measuring at different probe-detector distances.

An Application of the Scaled–Pixel–Counting Protocol to Quantify the Radiological Features of Anatomical Structures of the Normal Tarsal Joint in Horses

Abstract Background: As high-performance human and equine athletes train and compete at the highest level of effort, the prevention of high-performance-cased diseases, such as osteoarthritis (OA), requires knowledge of the anatomy and physiology of the subjected bones. Objective: Implementation of the scaled–pixel–counting protocol to quantify the radiological features of anatomical structures of the normal equine tarsal joint as the first step in the prevention of the tarsal joints OA in high-performance sport horses. Methods: A radiographic examination was performed in six cadaverous equine pelvic limbs. The dorso–plantar projection of the tarsal joint was performed using density standard (DS) attached to the radiographic cassette, standard X-ray equipment and standard diagnostic imaging protocol. On each of the radiographs, pixel brightness (PB) was extracted for each of the 10 steps (S1–S10) of DS. On each of the radiographs, seven regions of interest (ROIs) were annotated representing four bones (II tarsal bone [II TB], III tarsal bone [III TB], IV tarsal bone [IV TB] and central tarsal bone [CTB]) and three joints (proximal intertarsal joint [PIJ], distal intertarsal joint [DIJ] and tarsometatarsal joint [TMJ]), respectively. For each ROI, the percentage (%) of number of pixels (NP) from each range was calculated. Results: The % of NP was lower in bones than in joint spaces for S1–S6 and was higher in bones than in joint spaces for S8–S10. The % of NP was higher in PIJ than TMJ for S1 and higher in PIJ than DIJ for S4. No differences were found between consecutive bones for all examined steps of DS. Conclusions: An application of the scaled–pixel–counting protocol provides the quantitative radiological features of normal bone and joint structures of the tarsal joint in horses, making possible differentiation of the lucency of joint space and opacity of bone structure.