Osteoarthritis

Osteoarthritis is one of the most debilitating diseases affecting millions of people worldwide. However, there is no FDA approved disease modifying drug specifically for OA. Surgery remains an effective last resort to restore the function of the joints. As the aging populations increase worldwide, the number of OA patients increases dramatically in recent years and is expected to increase in many years to come. This is a book that summarizes recent advance in OA diagnosis, treatment, and surgery. It includes wide ranging topics from the cutting edge gene therapy to alternative medicine. Such multifaceted approaches are necessary to develop novel and effective therapy to cure OA in the future. In this book, different surgical methods are described to restore the function of the joints. In addition, various treatment options are presented, mainly to reduce the pain and enhance the life quality of the OA patients

ENHANCING KINEMATIC SHOULDER FUNCTION EVALUATION THROUGH A VALID, SIMPLE AND CLINICALLY APPLICABLE SCORE

Introduction Controversies surrounding Patient-Reported Outcome Measures (PROMs) and the cumbersome-nature of movement analysis-based (MAB) methods for shoulder function evaluation make the exploration of alternatives needed. Research aimed at the simplification of MAB outcome measures had demonstrated previously that the B-B Score, which relies on two movements only, was valid for out-of-laboratory evaluations of shoulder function. Nevertheless, further investigations were needed to optimise testing procedures, test the B-B Score’s capability of acquisition using a user-friendly device, and critically evaluate its measurement properties in comparison to current methods. Objective The aim of this thesis was to develop and assess the simplest possible MAB shoulder function scoring procedure for clinical measurement. Methods The research included four steps: 1) Optimisation of the B-B Score testing procedure (Phase 1 study [data-driven]), 2) Comparison of measurements using a smartphone or an inertial sensor system (Phase 2 study [data-driven]), 3) Validation in frequentlyoccurring pathologies (rotator cuff conditions, instability, fracture, capsulitis) (Phase 3 study [data-driven]), 4) Benchmarking of the new approach with concurrent MAB outcome measures and PROMs (literature review). Results Amongst the tested methods, the B-B score was optimised by using the mean of three replicates in the computation of the range of accelerations by angular velocities. The comparison of easily-used smartphone and reference device showed non-significant differences and excellent relationships between measurements (Intraclass Correlation Coefficient [ICC=0.97]). The smartphone’s B-B Score intra-rater and inter-rater reliability was excellent (ICC=0.92), but limits of agreement could reach up to ±19.4%. The score was responsive (area under the curve [AUC≥0.70]) and demonstrated excellent discriminative power between patients and controls (AUC≥0.90), except for shoulder instability (AUC=0.67). The correlations with PROMs were moderate to high. The benchmarking established that the measurement properties of the B-B Score compared equivalently with those of PROMs and MAB outcome measures, except for shoulder instability. Conclusion Shoulder function can be efficiently evaluated using a simple scoring procedure performed with a smartphone, which facilitates its objective assessment. Further research is needed to understand how best to reduce the effects of variability associated with single measurements in order to optimise clinical applicability and to explore the B-B Score’s properties in other situations requiring functional assessments of the shoulder. . Keywords: shoulder, shoulder function; outcome assessment; validation studies, reliability and validity; inertial sensors; smartphone sensors; body-worn sensors; kinematics; sensitivity and specificity

Development of a Biomimetic, Collagen-Based Scaffold for the Repair and Regeneration of the Annulus Fibrosus

Annually, over 5.7 million Americans are diagnosed with two IVD-associated pathologies: IVD herniation (IVDH- a mechanical disruption of the concentric fibrous layers of the annulus fibrosus (AF)) and/or degeneration (IVDD- a multifactorial process which initiates within the inner gelatinous core (NP), and results in a biochemical degradation of NP tissue), with over 2.7 million requiring surgical interventions. Although both underlying pathologies are different, quite often they both lead to a decrease in IVD height, impaired mechanical function, and increased pain and disability. These pain symptoms affect approximately 80% of the adult population during their lifetime with estimated expenditures exceeding $85.9 billion. Current surgical procedures for IVDH and IVDD are palliative and suffer from drawbacks. While they are performed to address patient symptoms, they fail to address the underlying pathology of a focal defect remaining within the subsequent outer layers of the AF. It is hypothesized that an effective AF closure/repair device in conjunction with a less aggressive discectomy for IVDH and/or NP arthroplasty for IVDD may result in improved patient outcomes, decreased pain, and provide fewer revision surgeries via lower re-herniation and expulsion rates. Therefore, an intact AF must be re-established to prevent implant expulsion or re-herniation, thus addressing the two major spinal pathologies directly associated with an IVD. Currently, within the medical device market, no tissue engineering biomaterials are available for AF closure/repair. Current market AF closure devices (Intrinsic Barricaid®, Anulex X-Close® Tissue Repair System, and Anulex Inclose® Surgical Mesh System) are synthetic materials focused solely on preserving and reinforcing the native tissue and lack effective strategies for implantation, fixation, and regeneration. Therefore, there has been an increase in tissue engineering and regenerative therapeutic approaches aiming for structural and biological AF repair investigated over the last decade using in vitro and in vivo experimentation. It is proposed that the optimum AF tissue engineering scaffold should reproduce the native AF microarchitecture and native mechanical properties. Recent articles illustrate several novel sutures, sealants, and barrier techniques currently under development, resulting in an increasing attention at scientific workshops and conferences. To develop a tissue engineering biomaterial that is suitable for AF closure we propose it must first meet the following criteria: (1) mimic the structural angle-ply architecture of the native AF, (2) fundamentally demonstrate mechanical properties mimicking the native functional characteristics, and (3) demonstrate cytocompatibility while promoting tissue regeneration. Current biomaterials gaining attention in the tissue engineering academic field, electrospinning, polymers, glue, silk scaffolds, and honeycomb-scaffolds, require complex manufacturing procedures and typically work to address two of the three criteria (mimicking the biological or structural characteristics). Therefore, the use of a decellularized tissue from a xenogeneic source may be ideal due to its advantage of maintaining native extracellular matrix (ECM) while also removing all potential harmful xenogeneic factors. Although, the mechanical advantage of closing annular focal defects to retain NP material seems intuitive, only recently have AF closure devices begun to examined in human cadaveric or animal tissues for their ability to withstand in situ IDP or flexibility testing. We propose to address all three criteria with the development of a biomimetic, collagen-based angle-ply annulus fibrosus repair patch (AFRP) comprised of the decellularized porcine pericardium. The porcine pericardium was chosen due to its innate type I collagen content, mechanical strength, and cytocompatibility. The objectives of this research were to investigate the development of this biomimetic AFRP to biologically augment AF repair by (1) mimicking and characterizing the micro-architecture of the multi-laminate angle-ply AFRP, (2) mechanically evaluating the AFRP’s mechanical properties and attachment strength in situ, (3) evaluating the ability of the AFRPs to support AF tissue regeneration in the context of a healthy and inflammatory environment, and (4) evaluating the in vivo mechanical strength, biocompatibility, and tissue regeneration capacity of the AFRP in a large animal model for intervertebral disc degeneration/herniation

Low Back Pain Pathogenesis and Treatment

Low back pain is a common disorder which affects the lumbar spine, and is associated with substantial morbidity for about 80% of the general population at some stages during their lives. Although low back pain usually is a self-limiting disorder that improves spontaneously over time, the etiology of low back pain is generally unknown and the diagnostic label, "non-specific low back pain", is frequently given. This book contains reviews and original articles with emphasis on pathogenesis and treatment of low back pain except for the rehabilitative aspect. Consisting of three sections, the first section of the book has a focus on pathogenesis of low back pain, while the second and third sections are on the treatment including conservative and surgical procedure, respectively

Wear and rim damage of UHMWPE acetabular cups in total hip replacement

Wear and fatigue of polyethylene acetabular cups have been reported to play a role in the failure of total hip replacements. Edge loading of hip replacements can occur where there is sub-optimal component positioning and/or joint laxity. Wear resistance can be improved by crosslinking but the manufacturing process of these materials involves post-irradiation thermal treatments to recombine free radicals and to stabilise the materials. Stabilisation can also be achieved by adding antioxidants. Material degradation due to oxidation and manufacturing process can result in rim cracking and/or fracture due to a reduction in mechanical properties and this has been observed in vivo. A requirement for pre-clinical hip simulator testing under edge loading conditions for all of these materials has therefore been identified. This thesis describes the development and evaluation of a hip simulator edge loading protocol using accelerated aged conventional UHMWPE acetabular liners as positive controls and commercially available crosslinked UHMWPE acetabular liners as negative controls. The edge loading protocol was then used to evaluate antioxidant stabilised liners in hip simulator tests. Explanted UHMWPE acetabular liners were evaluated for wear and damage mechanisms and compared with the damage observed on the hip simulator tested liners and new methodologies were developed to measure and analyse these explanted liners. The edge loading protocol produced cracking and subsurface damage in the aged UHMWPE liners but not in the non-aged crosslinked liners. Rim deformation was observed on all liners and the volume change produced was reduced under edge loading conditions for both types of UHMWPE liner. The antioxidant liners performed as well as the commercially available crosslinked liner in hip simulator tests and the rim deformation that was observed on explanted liners was replicated under edge loading conditions in the hip simulator tests. The edge loading protocol can be used in the future to test a range of UHMWPE materials, including aged materials, and explant analysis using the methodologies developed in this study can be used to inform the design of future simulator tests

Advanced Applications of Rapid Prototyping Technology in Modern Engineering

Rapid prototyping (RP) technology has been widely known and appreciated due to its flexible and customized manufacturing capabilities. The widely studied RP techniques include stereolithography apparatus (SLA), selective laser sintering (SLS), three-dimensional printing (3DP), fused deposition modeling (FDM), 3D plotting, solid ground curing (SGC), multiphase jet solidification (MJS), laminated object manufacturing (LOM). Different techniques are associated with different materials and/or processing principles and thus are devoted to specific applications. RP technology has no longer been only for prototype building rather has been extended for real industrial manufacturing solutions. Today, the RP technology has contributed to almost all engineering areas that include mechanical, materials, industrial, aerospace, electrical and most recently biomedical engineering. This book aims to present the advanced development of RP technologies in various engineering areas as the solutions to the real world engineering problems

Biomechanical Evaluation of Total Ankle Replacements

Globally, 1% of the population is affected by arthritis of the foot and ankle. Total ankle replacement (TAR) was developed as an alternative to fusion to treat end-stage arthritis, however failure rates are relatively high and are often related to bony damage. The purpose of this PhD was to develop a finite element (FE) model of a TAR to examine the risk of bone failure, and how this is affected by component alignment. An experimental model of a TAR implanted into synthetic bone was first created as a means to validate an initial FE model under known conditions. Location and size of the plastic deformation were compared and good agreement was found. A FE model of the natural ankle was then created from cryosectional images obtained from the Visible Human Project®. It was analysed in the natural state and after virtual implantation with a TAR. Both the cortical stiffness and the surgical positioning of the TAR were varied to represent relevant ranges seen clinically. In the TAR models, the location of the highest stress was shifted from the region of high strength to a region of lower strength of bone. The maximum von Mises stress on the cancellous bone was primarily affected by the stiffness of cortical structure and the distance between the stem and the outer surface of the cancellous bone. In some misalignment cases, the yield stress for cancellous bone was likely to be exceeded under loads representing standing. The results indicated that the quality of the bone and the thickness of the trabecular bone surrounding the TAR stem are important factors in governing the risk of bony failure following TAR, and should be taken into account clinically. The methods developed in this thesis can now be extended to examine other TAR designs and surgical approaches

Towards understanding the functionality of foot orthosis based on foot structure and function

The raw data related to the second study of this thesis (Chapter 3) is available online in the section of supporting information at https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0232677. These files present the following data: S1 File. The pattern of foot orthosis depression/reformation for healthy subjects during walking with sport versus regular foot orthosis. S2 File. Raw data for the training session of sport foot orthosis. This Excel file consists three sheets in which the position of triad markers, the orientation of triad markers and the position of markers on plantar surface of foot orthosis are provided respectively. S3 File. Raw data for walking with sport foot orthosis. This Excel file consists two sheets in which the position of triad markers and the orientation of triad markers are provided respectively for subject 1. S4 File. The results of each participant during walking with sport foot orthosis. This .mat file includes “DispEachPoint” and “DispEachPointMean” which shows the displacement of each predicted marker on foot orthosis plantar surface during stance phase of walking relative to its corresponding position in static non weight-bearing for each trial and the average of trials respectively. In addition, “loc_stance” and “loc_meanstance” show the location of each predicted marker during stance phase of walking. “peaks” and “peaksMean” represent the minimum (depression) and maximum (reformation) value of displacement during walking S5 File. The results of each participant during walking with regular foot orthosis. This .mat file includes “DispEachPoint” and “DispEachPointMean” which shows the displacement of each predicted marker on foot orthosis plantar surface during stance phase of walking relative to its corresponding position in static non weight-bearing for each trial and the average of trials respectively. In addition, “loc_stance” and “loc_meanstance” show the location of each predicted marker during stance phase of walking. “peaks” and “peaksMean” represent the minimum (depression) and maximum (reformation) value of displacement during walkingLes orthèses plantaires (OP) sont des dispositifs médicaux fréquemment utilisés pour réduire les douleurs et blessures de surutilisation, notamment chez les personnes ayant les pieds plats. Le port d'OP permettrait de corriger les altérations biomécaniques attribuées à la déformation du pied plat, que sont la perte de l’arche longitudinale médiale et la pronation excessive du pied. Cependant, le manque de compréhension de la fonction des OP entraine une grande variabilité des OP prescrites en milieu clinique. L'objectif de cette thèse est d'approfondir les connaissances sur l’effet des OP sur la biomécanique, de quantifier les déformations des OP à la marche et de mettre en relation ces déformations avec la biomécanique du pied. La première étude a évalué la manière dont les différentes conceptions d'OP imposent des modifications dans le mouvement et le chargement appliqué sur le pied. Cet objectif a été atteint grâce à une revue systématique traitant des effets des OP sur la cinématique et la cinétique du membre inférieur pendant la marche chez des personnes ayant des pieds normaux. Les critères d'inclusion ont réduit les études à celles qui ont fait état des résultats pour les géométries les plus fréquentes des OP, à savoir les biseaux, les supports d’arche et les stabilisateurs de talon. La revue a mis en évidence que les orthèses avec un biseau médial peuvent réduire le moment d'éversion de la cheville. Aucune évidence significative n'a été trouvée dans notre méta-analyse sur l'efficacité des orthèses incluant des supports d’arche ou des stabilisateurs de talon. Les différents procédés et matériaux utilisés dans la conception des OP ainsi que les caractéristiques des pieds des participants pourraient expliquer la variabilité retrouvée au regard des effets des OP sur la biomécanique. La deuxième étude a apporté des informations précieuses et inédites sur le comportement dynamique des OP à la marche. La cinématique du contour des OP a été utilisée pour prédire la déformation de leur surface plantaire pendant la marche chez 13 individus ayant des pieds normaux en utilisant un réseau de neurones artificiels. Une erreur moyenne inférieure à 0,6 mm a été obtenue pour nos prédictions. En plus de la précision des prédictions, le modèle a été capable de différencier le patron de déformations pour deux OP de rigidités différentes et entre les participants inclus dans l’étude. Enfin, dans une troisième étude, nous avons identifié la relation entre la déformation des OP personnalisées et la biomécanique du pied à la marche chez 17 personnes avec des pieds plats. L'utilisation de modèles linéaires mixtes a permis d’exprimer les variations de la déformation des OP dans différentes régions en fonction des variables cinématiques du pied et de pressions plantaires. Cette étude a montré que l'interaction pied-OP varie selon les différentes régions de l’OP et les différentes phases du cycle de marche. Ainsi, des lignes directrices préliminaires ont été fournies afin de standardiser et optimiser la conception des OP. Dans l'ensemble, les résultats de cette thèse justifient l'importance d’'intégrer des caractéristiques dynamiques du pied de chaque individu dans la conception d'OP personnalisées. Des études futures pourraient étendre les modèles de prédiction de l'interaction pied-OP en incluant d'autres paramètres biomécaniques tels que les moments articulaires, les activations musculaires et la morphologie du pied. De tels modèles pourraient être utilisés pour développer des fonctions coût pour l'optimisation de la conception des OP par une approche itérative utilisant la simulation par les éléments finis.Foot orthoses (FOs) are frequently used medical devices to manage overuse injuries and pain in flatfoot individuals. Wearing FOs can result in improving the biomechanical alterations attributed to flatfoot deformity such as the loss of medial longitudinal arch and excessive foot pronation. However, a lack of a clear understanding of the function of FOs contributes to the highly variable FOs prescribed in clinical practice. The objective of this thesis was to deepen the knowledge about the biomechanical outcomes of FOs and to formulate the dynamic behaviour of FOs as a function of foot biomechanics during gait. The primary study investigated how different designs of FOs impose alterations in foot motion and loading. This objective was achieved through a systematic review of all literature reporting the kinematics and kinetics of the lower body during walking with FOs in healthy individuals. The inclusion criteria narrowed the studies to the ones which reported the outcomes for common designs of FOs, namely posting, arch support, and heel support. The review identified some evidence that FOs with medial posting can decrease ankle eversion moment. No significant evidence was found in our meta-analysis for the efficiency of arch supported and heel supported FOs. The findings of this study revealed that differences in FO design and material as well as foot characteristics of participants could explain the variations in biomechanical outcomes of FOs. The second study provided valuable information on the dynamic behaviour of customized FOs. The kinematics of FO contour was used to predict the deformation of FO plantar surface in 13 healthy individuals during walking using an artificial intelligence approach. An average error below 0.6 mm was achieved for our predictions. In addition to the prediction accuracy, the model was capable to differentiate between different rigidities of FOs and between included participants in terms of range and pattern of deformation. Finally, the third study identified the relationship between the deformation of customized FOs and foot biomechanics in 17 flatfoot individuals during walking. The use of linear mixed models made it possible to identify the variables of foot kinematics and region-dependent plantar pressure that could explain the variations in FO deformation. This study showed that the foot-FO interaction changes over different regions of FO and different phases of gait cycle. In addition, some preliminary guidelines were provided to standardize and optimize the design of FOs. Overall, the results of this thesis justify the importance of incorporating the dynamic characteristics of each individual’s foot into the design of customized FOs. Future studies can extend the predictive models for foot-FO interactions by including other determinants of foot biomechanics such as joint moments, muscle activation, and foot morphology. Based on such extended models, the cost functions could be devised for optimizing the designs of customized 3D printed FOs through an iterative approach using finite element modeling