The focus of this dissertation is on the development of a solid freeform fabrication (SFF) process for the design and manufacture of porous biodegradable orthopaedic implants from calcium polyphosphate (CPP). Porous CPP structures are used as bone substitutes for regenerating bone defects and/or as substrates in formation of so-called “biphasic” implants for repair of damaged osteochondral tissues. The CPP implants can be utilized in the treatment of many musculoskeletal diseases, osteochondral defects, and bone tumours while replacement of the defect site is required. In this study, the fabrication of CPP structures was developed through a powder-based SFF technique known as adhesive bonding 3D-printing. SFF is an advanced alternative to the “conventional” fabrication method consisting of gravity sintering of CPP pre-forms followed by machining to final form, as SFF enables rapid manufacturing of complex-shaped bio-structures with controlled internal architecture. To address the physical and structural properties of the porous SFF-made components, they were characterized using scanning electron microscopy, micro-CT scanning and mercury intrusion porosimetry. Specific surface area and permeability of the porous structures were also determined. Additionally, the chemical properties (crystallinity) of the specimens were identified by X-ray diffraction. The mechanical properties of the crystalline CPP material were also measured by micro- and nano-indentation. Moreover, the porous structures were tested by uniaxial and diametral mechanical compression to determine the compressive and tensile strengths, respectively. Furthermore, the effect of the stacked-layer orientation on the mechanical properties of the SFF-made constructs was investigated through the production of samples with horizontal or vertical stacked-layers. The properties of the SFF-made samples were compared with those of the conventionally-made CPP constructs. The SFF-made implants showed drastically higher compressive mechanical strength compared to the conventionally-formed samples with identical porosity. It was also shown that the orientation of the stacked-layer has substantial influence on the mechanical strengths. Moreover, this thesis examined the ability of in vitro forming of cartilaginous tissue on the SFF-made substrates where the chondrocytes cellular response to the CPP implants was evaluated histologically and biochemically. In addition, an initial in vivo assessment of the CPP structures as bone substitutes was conducted using a rabbit medial femoral site model. Significant amount of new-bone was formed within the CPP porous constructs during the 6-week implantation period demonstrating appropriate biological response of SFF-made CPP structures for bone substitute applications. Another accomplishment of this thesis was the development of a mathematical model which predicts the compact density of powder layers spread by a counter-rotating roller in the SFF technique. The results may be used in the control of the apparent density of the final implant. The potential of the developed SFF method as an efficient and reproducible technique for the production of porous CPP structures for use in orthopaedics and musculoskeletal tissue regenerative applications was concluded.

[Truncated abstract] Hyaline articular cartilage is a highly specialised tissue consisting of chondrocytes embedded in a matrix of proteoglycan and collagens. Hyaline articular cartilage withstands high levels of mechanical stress and continuously renews its extracellular matrix. Despite this durability, mature articular cartilage is vulnerable to injury and disease processes that cause irreparable tissue damage. Native hyaline articular cartilage has poor regenerative capacity following injury, largely due to the tissue's lack of blood and lymphatic supply, as well as the inability of native chondrocytes to migrate through the dense extracellular matrix into the defect site. Articular cartilage injuries that fail to penetrate the subchondral bone plate evoke only a short-lived metabolic and enzymatic response, which fails to provide sufficient new cells or matrix to repair even minimal damage. Clinically, it has previously been accepted that treatment of such defects does not result in the restoration of normal hyaline articular cartilage, which is able to withstand the mechanical demands that are placed on the joint during every day activities of daily living. ... Historically, rehabilitation following ACI has not kept pace with the advances in cell culture and surgical technique. Subsequently, there exists a significant gap in knowledge regarding `best practice' in post operative rehabilitation following ACI. The importance of structured rehabilitation in ACI should not be underestimated when evaluating the clinical success of this chondral treatment. Patients should not be left to their own devices following ACI surgery, as the risk of damage to their implant (via delamination) is high if immediate postoperative movement is not controlled. Furthermore, the biological longevity and clinical success of the graft is dependent on a controlled and graduated return to ambulation and physical activity, and the biomechanical stimulation of the implanted chondrocytes.

The Taylor Spatial Frame (TSF) is a recently introduced form of a circular external orthopaedic fixator for long bone fracture reduction and deformity correction. The TSF is constructed from two circular rings interconnected with six variable-length struts. Its kinematics are based on the Stewart-Gough platform. The TSF is attached to the patient's anatomy using fine wires and half-pins. In this thesis, three aspects of the TSF are analysed. First, the solution to non-trivial forward and inverse kinematics has been addressed. Second, the mechanical properties of the TSF fixator are investigated. Individual component stiffness is assessed separately and then the complete fixator is modelled. Simple stiffuess models of fine wires and half-pins are derived. Considerations for the use of the TSF for the peri-articular fractures are investigated and potential modifications are proposed. The effect of backlash in the frame components on the accuracy of the fixator has been analysed. Finally, in rder to validate the kinematics solution, to provide a training aid for surgeons and to demonstrate the concept of accurately controlled interfragmentary motion, a prototype of an active TSF was designed and built. Computationally efficient algorithms for solving the forward and inverse kinematics have been developed that require little numerical processing overhead and can be implemented on a mobile computing device. It was found that the TSF fixator has similar axial stiffuess to the circular Ilizarov ring fixator, since wires and half-pins are significantly less stiff than the frames. Furthermore, the TSF exhibits more uniform stiffuess for a range of off-axis loads and is significantly stiffer for torsional loads than the Ilizarov fixator. Slack, in the form of a backlash, can lead to severe strains in the unloaded frames and therefore fractures, and hence precautions are recommended. Finally, considerations and prototype for the automated TSF are presented that can be utilised for demonstration purposes and surgeon training.

The aim of the thesis was to collect baseline data and to investigating suitable physical tests and a self-rapport questionnaire. Collected data was used to find a routine measurement when investigating foot health, function and mobility among clients suffering from diabetes in Samoa. Twenty-one participants suffering from diabetes were included in the study. Clients answered the Foot function index (FFI) questionnaire and performed physical tests, consisting of Bergs balance scale (BBS) and Time up and go (TUG). Results from the physical tests revealed a great balance disturbance and mobility limitations among the majority of the clients. General high weight and BMI was measured among both genders. Subjects with the highest BMI performed lowest time during TUG test. The statistic analyze revealed a strong correlation between the two physical tests, indicating that one of the tests could be applied as a routine measurement in the future, when evaluating function and mobility in Samoa. The compilation of self-report questionnaires indicated a general good foot health with a low amount of pain, disabilities and activity limitations. / Syftet med studien var att samla in grundata och att hitta ett lämpligt fysiskt test och ett självadministrativt formulär. Den insamlade grunddatan användes för att hitta ett rutinmässigt mätinstrument för undersökning av fothälsa, funktion och mobilitet hos klienter som lider av diabetes i landet Samoa. I undersökningen deltog 21 personer som lider av diabetes. Deltagarna fick besvara ett så kallat ”Foot Function Index formulär” (FFI) och utföra de två fysiska testerna ”Bergs Balance Scale” (BBS) och ”Time Up and Go” (TUG). Resultaten från de fysiska testerna påvisade såväl en stor balansrubbning som mobilitetsbegränsningar hos majoriteten av deltagarna. Ett generellt högt BMI-värde och stor vikt uppmättes hos båda könen. Personer med högst BMI-värde presterade kortast tid under TUG-testet. Den statistiska analysen påvisade en stark korrelation mellan de två fysiska testen, vilket indikerar att endast ett av testerna kan användas som mätinstrument i framtida undersökningar av funktion och mobilitet på Samoa. Sammanställningen av de självadministrativa formulären påvisade en generellt god fothälsa med begränsad smärta, oförmåga och aktivitetsbegränsning hos deltagarna i studien.

The aim of this thesis was to investigate how to construct a system to measure load in a mobile unicompartmental knee replacement (UKR) bearing. In vivo loads have been measured in a total knee replacement (TKR), but with TKR the kinematics are different from those of the normal knee, whereas they are close to normal in a mobile UKR, so the loads measured by an instrumented UKR would be more representative of the normal knee. On the principle of measuring compression of an object under load, the load may be estimated. Compression measurement using a capacitive sensor was the optimal solution to measure load, based on life expectancy of the sensor and bearing integrity. A capacitive sensor within a polyethylene (UHMWPE) bearing has not been used before. The visco-elastic and temperature dependent properties of UHMWPE were determined with experiments. UHMWPE had an approximately linear response after ten minutes of applying a constant load. A temperature sensor should be used in vivo to compensate for temperature effects acting on the elastic modulus of UHMWPE. Finite element modelling demonstrated that positioning the sensor under the centre of the bearing concavity resulted in the largest capacitive change. The influence of various dimensional parameters on sensor output was simulated, and the conclusion was that the sensor only needs to be calibrated once. An electronic module inserted into a bearing had less than 5 % influence on bearing compression. Capacitive sensors were made from polyimide, using standard production methods, and embedded within a UKR bearing using the standard compression moulding process. The embedded sensor had a second order low pass frequency response, with a corner frequency of 9 Hz, twice the frequency required for typical functional loading such as gait. Physiological load signals, gait and step up/down, were applied to the bearing. The capacitance to load response was approximately linear. Load was estimated using a linear method and a dynamic method. The linear method performed best, with an accuracy of force estimation better than 90 %. In vitro tests were performed using a commercially available transceiver, two stan- dard antennas and a custom antenna, designed to be incorporated in the bearing. Wireless communication between an implanted custom antenna and an external an- tenna was shown to be feasible. Experiments were also performed that demonstrate that inductive powering of the bearing was feasible. In addition to load measurement, a proposal for dynamic measurement of the orien- tation angles of both the tibia and the femur was made. Power and volume calculations showed that it is possible to place an electronic module within the bearing. This thesis has not only demonstrated that it is feasible to make an instrumented bearing for UKR but has also provided a basic design for manufacturing.

The thesis analyses the company Beznoska s.r.o. on the domestic and foreign markets. It describes the activities and strategy of the company, which is engaged in the production of orthopaedic implants and implants in the field of orthopaedics. The second part of the thesis focuses on the analysis of the domestic market, i.e. the Czech Republic. It analyses particularly Ukraine from the foreign markets. Subsequently, by using comparison and analysis among the selected countries, it is searching for potential market for company expansion.

Syfte: Denna studie syftar till att undersöka vilken behandlingsmetod, plasticitetsgrundad eller icke-invasiv neuromodulering som presenterar bäst resultat av smärtlindring hos personer som upplever fantomsmärtor efter en amputation. Metod: Litteraturundersökningen utfördes i 3 databaser; MEDLINE, CINAHL och PsycINFO. Inkluderingskriterier användes för urval av studier. Bedömning av studiernas risk för bias gjordes med hjälp av mallar från Joanna Briggs Institut. Relevant data kopplad till frågeställningen extraherades och analyserades. Resultat: Totalt åtta artiklar inkluderades, där två presenterade resultat från icke-invasiv neuromodulering och sex studier inkluderade plasticitetsgrundade metoder. Smärtskalor mellan 0-10 användes för att mäta förändringen av smärtan. Den kritiska bedömningen drog slutsatsen att det saknades studier av hög kvalitet som inkluderar kontrollgrupper. Bevisen som analyserats i den aktuella studien indikerar att plasticitetsgrundade metoder tycks ge bättre smärtreduktion jämfört med icke-invasiv neuromodulering. Slutsats: Baserat på resultaten kan inte denna studie presentera bevis starka nog för att avgöra vilken grupp av metoder som har bäst smärtlindrande effekt. Brist av högkvalitativa studier inom området, i kombination med heterogenitet mellan inkluderade studier resulterar i att ingen slutsats kan dras. / Aim: This study aims to determine which treatment method, plasticity guided or non-invasive neuromodulation, presents the best result in reducing pain for amputees experiencing phantom limb pain. Method: Literature search was performed in 3 databases; MEDLINE, CINAHL and PsycINFO. Eligibility criteria were used for study selection. Critical appraisal tool by Joanna Briggs institute was used to assess the included articles’ risk of bias. Data relevant to the research question were extracted and analyzed. Result: A total of eight articles were included, where two presented results from non-invasive neuromodulation and six studies included plasticity guided methods. Pain scales ranging from 0-10 were applied as outcome measures to monitor improvements in phantom limb pain. The critical appraisal concluded lack of high-quality study designs including control groups. The evidence analysed in the present study indicate that plasticity guided methods appear to provide the best pain reduction when compared to non-invasive neuromodulation. Conclusion: Based on the results, this study does not present evidence strong enough to state which methods present the best pain reduction. Due to low amount of research within the field, combined with heterogeneity between included studies, no conclusion can be made.

With an increasing prevalence of osteoarthritis, total knee (TKA) and hip (THA) arthroplasty are the second-and third-most common surgeries in Canada. Although these procedures improve pain and function for a majority of patients, some patients report persistent postoperative pain. Opioids are conventionally used for these patients even though they are associated with addiction, falls, overdose, and death. Recently, many strategies have been proposed to decrease reliance on opioids after TKA and THA, including opioid-free and opioid-reduced multimodal protocols for pain management. Our findings demonstrate that Canadian patients’ receptivity to opioid-free or reduced postoperative protocols is associated with their perception of the efficacy and safety of opioids compared to non-opioid alternatives, and current opioid use. More patients are open to opioid-reduced postoperative care as they perceive that pain will be intolerable without opioids. This overlaps with many Canadian surgeons’ perception that opioids cannot be completely eliminated from postoperative pain management regimens and that patients expect an intolerable level of pain after surgery, warranting opioid use. This highlights a need for enhanced patient education on the safety and efficacy of opioids and alternatives, while managing patients’ expectations of postoperative pain control. Most Canadian and Dutch surgeons reported that they prescribe opioids to nearly all of their patients postoperatively. However, our cross-sectional study indicates that 40% of Canadian patients would be open to receiving no opioids postoperatively. In contrast, Japanese surgeons believed that opioids are unnecessary for managing postoperative pain. Variations observed among orthopaedic surgeons in Canada, the Netherlands, and Japan can be attributed to differences at the surgeon-level (individual practices and beliefs), patient-level (patient characteristics and preferences), and system-level (regulatory frameworks and healthcare systems). Further research is required on surgeon-centered approaches to mitigating opioid use, focusing on education and guidelines/policies for opioid prescribing. / Thesis / Master of Science (MSc) / Opioid analgesics are routinely prescribed to manage pain after total knee and hip replacement surgery. However, opioids are not typically more effective than alternatives and are associated with addiction, overdose, and death. This thesis aims to understand the perceptions of patients and orthopaedic surgeons on opioid use after total knee and hip replacement surgery. The findings demonstrate that more patients are open to receiving opioid-reduced surgery compared to opioid-free surgery, with receptivity being associated with patients’ perceptions of opioid efficacy and safety and current opioid use, highlighting a need for improved patient education. Additionally, orthopaedic surgeons identified challenges and facilitators to postoperative opioid reduction in six key areas: opioid prescribing practices, patient factors, collaborative care, policies/guidelines, surgeon education and training, and personal perceptions/beliefs. Compared to Canadian and Dutch surgeons, Japanese surgeons heavily relied on non-opioid medications as they believed that opioids are unnecessary for managing postoperative pain.

Background: There is limited research on how web-based, point-of-care, evidence-based medicine (EBM) tools, such as evidence summaries, are being implemented and used in developing countries. Objectives: To investigate accessibility, use, and impact of an online EBM knowledge dissemination portal in orthopaedic surgery. To explore whether receiving daily targeted evidence summaries results in more frequent use of an EBM tool compared with receiving general weekly reports. To identify and explain the barriers and benefits of a point-of-care resource in the Indian context. Methods: Forty-four orthopaedic surgeons in Pune, India, were provided free access to OrthoEvidence (OE), a for-profit, online EBM knowledge dissemination portal. Participants were subsequently randomized to an Intervention group receiving daily targeted evidence summaries or a Control group receiving general weekly summaries. This study employed an explanatory sequential mixed methods design that incorporated two questionnaires, OE usage data, and semi-structured interviews to gain insight into the surgeons’ usage, perceptions and impact of OE. Results: There were no observable differences in OE usage between the Intervention and Control groups. OE was deemed to be comprehensive, practical, useful, and applicable to clinical practice by the majority of surgeons. The exit survey data revealed no differences between groups’ perceptions of the OE tool. Semi-structured interviews revealed barriers to keeping up with evidence that included limited access to relevant medical literature (limited internet connection, lack of time, minimal access to medical journals) and limited incentive to keep up with it (limited decision-making powers for residents, textbook-based residency curriculum, lack of research methods knowledge, limited context-specific research). Changing trauma practices at the hospital were noted following the intervention. Recommendations: The practice of EBM and the use of point-of-care tools in India can be promoted by investing in adequate electronic infrastructure (improvements to internet access) and by integrating EBM into training programs and surgical cultures. / Thesis / Master of Science (MSc)

<p>This study is focused on synthesizing Nitinol by additive manufacturing that can provide desirable mechanical properties for orthopedic implants and adding functionally gradient coating that can enhance both safety and biocompatibility for orthopedic implant applications.</p> <p><br></p> <p>The characteristics of additively manufactured Nitinol, by using the direct energy deposition (DED) technique, were experimentally studied. Because of a unique layer-by-layer manufacturing scheme, the microstructure and associated properties (mechanical and thermo-mechanical properties) of the DED Nitinol is different compared to conventionally produced Nitinol. Both the feasibility of manufacturing defect-free microstructure and the precise control of chemical composition were demonstrated. Effects of chemical compositions and post heat-treatment conditions on the phase transformation temperatures of the DED Nitinol were systematically analyzed and compared with those of conventional Nitinol. More precise control of phase transformation temperature from DED Nitinol was possible due to incoherent precipitate formation during aging heat treatment. In a similar way, the mechanical properties of the DED Nitinol were less sensitive to its chemical compositions and post heat-treatment conditions. The feasibility of the precise control of both mechanical and thermo-mechanical properties of the DED Nitinol was demonstrated which can broaden its applications. </p> <p><br></p> <p>The bulk polycrystalline properties of the NiTi phase were studied via molecular dynamics (MD) simulations. Thermo-mechanical properties that are highly sensitive to chemical composition were not precisely predicted from previous reports and studies. In this study, realistic boundary conditions were applied to calculate bulk polycrystalline properties. Thermally driven phase transitions of NiTi between martensite and austenite are simulated with external stresses in both normal and shear directions. It is shown that phase transformation temperatures are affected by applied external stresses, and realistic values compared to experimental data are correctly predicted only when external stresses in both normal and shear directions are similar to the experimentally observed values of 0.05 – 0.1 GPa. The experimentally observed grain orientation and grain boundary thickness were applied to simulation domains for the prediction of the elastic moduli. The elastic moduli of polycrystalline NiTi structure was calculated as 52 GPa which is close to the experimentally reported value of 20-40 GPa while other studies predicted over 85 GPa. </p> <p><br></p> <p>Lastly, pure titanium gradient layers were coated on the Nitinol surface for orthopedic implant applications to eliminate potentially toxic Ni ion release. Using the DED technique, both the core Nitinol and titanium gradient layers were manufactured with high purity and without microstructural defects. An additional biomedical coating of Hydroxyapatite (HA) was deposited on the outer surface using the cold spray technique. The resultant bonding strength was determined to be 26 MPa which exceeded the requirement of the ISO-13779 standard (15 MPa). The <em>in vitro</em> test of the Ni release rate from the entire gradient Nitinol structure was very low, which was comparable to drinking water.</p>