The work deals with the lubrication of total knee replacement using fluorescence microscopy method, which allows unique insight into the contact between femoral and tibial component. The aim was to determine the effect of composition of synovial fluid (i.e. albumin, -globulin, hyaluronic acid and phospholipids) on film thickness and protein behaviour in contact, and also to determine changes of contact area during rotation. Since this is the first experimental work dealing with a knee replacement lubrication primarily, only simple rotation and load cycles were applied by the knee simulator. The output of the experiments was fluorescence intensity, which corresponds to dimensionless film thickness, over time. Another important output are the images directly showing the fluorescently labelled proteins in the contact area. The results show, there are fundamental differences in lubrication in different positions of rotation, due to changes of position, shape and behaviour of the contact area. The composition of the lubricant is also essential, since the proteins themselves form a relatively strong lubricating film and their mixture leads to a substantial reduction of film thickness, due to significant formation of clusters. Complex fluid, although it does not form the strongest layer, is able to create a quite continuous film.

BACKGROUND: Tranexamic acid (TXA) has become highly utilized in total joint arthroplasties for its anti-fibrinolytic effect. Recently, intra-articular application of TXA has become popular for its avoidance of systemic distribution within the body. With a more direct application to the surgical site, there is interest to see if topical application will provide hemostasis without increasing rates of venous or arterial thrombotic events and infections. In particular, there is lack of published data describing the safety of TXA in patients who have a significant disposition towards thromboembolic events. METHODS: This study was a retrospective chart-review (RCR) to assess the safety and efficacy of intra-articular TXA (IA-TXA) in total knee and hip arthroplasty patients. IA-TXA 2g/50mL NS was administered to patients who were contraindicated for IV-TXA usage based on our hospital’s guidelines (history of VTE events, mitral or aortic valve replacement with additional risk factors for stroke, active cancer, genetic or acquired thrombophilia, significant cardiac disease, serum creatinine > 2.8 mg/dL). Primary efficacy outcomes were total blood loss on post-operative day 1 (POD1), overall perioperative blood loss, and changes in hemoglobin/hematocrit values over the hospital stay. Primary safety outcomes were the incidence of arterial or venous thrombosis and wound infections. The study compared patients who received IA-TXA (study group) to patients who did not receive TXA (control group). The study included TKA patients=156 (Control=72 Study=83), anterior THA patients=57 (Control=20 Study=37), and posterior THA patients=59 (Control=27 Study=32). RESULTS: TKA patients administered IA-TXA showed a significant decrease in POD1 blood loss compared to the control group [305.84 mL, p = 0.004]. Additionally, the control patients showed significantly lower levels of overall hematocrit than those who had received IA-TXA [0.9 units, p = 0.041]. However, IA-TXA did not cause a reduction in blood loss in either the anterior or posterior THA patients. No statistically significant differences existed between treatment and control groups for transfusion rates or post-operative complications (VTE events and infections). CONCLUSION: IA-TXA 2g/50mL is effective in reducing blood loss in TKA patients; however, further research is needed regarding IA-TXA use in THA patients. The lack of efficacy in THA may have been related to the dosage used, the volume instilled, the timing of administration, or technique of administration.

abstract: Falls are the leading cause of fatal and non-fatal injuries in the older adult population with more than 27,000 fall related deaths reported every year[1]. Adults suffering from lower extremity arthritis have more than twice the likelihood of experiencing multiple falls resulting in increased fall-related injuries compared to healthy adults. People with lower extremity end-stage osteoarthritis(KOA), experience a number of fall risk factors such as knee instability, poor mobility, and knee pain/stiffness. At end-stage knee OA, the space between the bones in the joint of the knee is significantly reduced, resulting in bone to bone frictional wearing causing bone deformation. In addition, an impaired stepping response during a postural perturbation is seen in people with OA related knee instability. The most common treatment for end-stage knee osteoarthritis is a surgical procedure called, total knee replacement (TKR). It is known that TKR significantly reduces pain, knee stiffness, and restores musculoskeletal functions such as range of motion. Despite studies concluding that knee OA increases fall-risk, it remains unknown if standard treatments, such as TKR, can effectively decrease fall-risk. Analyzing the compensatory step response during a fall is a significant indicator of whether a fall or a recovery will occur in the event of a postural disturbance and is key to determining fall risk among people. Studies have shown reduced trunk stability and step length, as well as increased trunk velocities, correspond to an impaired compensatory step. This study looks at these populations to determine whether TKR significantly enhances compensatory stepping response by analyzing trunk velocities and flexions among other kinematic/kinetic variable analysis during treadmill induced perturbations and clinical assessments. / Dissertation/Thesis / Masters Thesis Biomedical Engineering 2019

The purpose of this study was to investigate the influence of tibial stem geometry on stress shielding of the tibia for patients with a total knee replacement. Finite element analysis was used to study different tibial stem geometry types, as well as a vast array of different geometric sizes. Both a peg and stem type geometry were analyzed and compared in order to determine what type geometry causes the least amount of stress shielding. A static loading condition with a dynamic loading factor of three was used for the system and the stress responses were analyzed at regions of interest at various depths. Regions of interest include the posterior and medial regions, at depths ranging from the resurfaced tibial surface to 100 mm below the surface. It was found that the smallest stem/peg sizes produced the least amount of stress shielding, indicating that the less amount of foreign material within the tibia, the more natural the bending and stress response of the tibia. It was also concluded that for the loading conditions used in this study, peg type geometry yields a decreased amount of stress shielding when compared to stem type geometry. This is due to the fact that the peg type geometry allowed for more natural bending and a distributed loading transfer between two pegs rather than one long central stem. Further studies should be completed on other geometry types in order to understand how to best replicate the natural bending of the tibia.

BACKGROUND: There has been an enormous rise in total joint arthroplasties (TJA) in the United States over the past several years. Researchers have documented the increase in healthcare costs associated with unplanned hospital readmissions among patients post-TJA, specifically total hip and total knee arthroplasties. Additionally, researchers have reported the burden that these costs place on the healthcare system, private payers and on patients and their caregivers. Social routines, quality of life and occupational functioning are often interrupted because of a patient’s unplanned hospital readmission after receiving a total hip or total knee arthroplasty. Investigators have identified the major causes of costly unexpected hospital readmissions among patients with a TJA; they include surgical site infections, blood clots, joint dislocations and periprosthetic fractures. The Occupational Therapy Practice Framework: Domain and Process describes the practice of occupational therapy as promoting health, well-being, and engagement in meaningful occupation. Nonetheless, there is limited literature in the occupational therapy field directed towards reducing hospital readmissions among patients with a total hip or knee arthroplasty, thus suggesting an area that is well-positioned for intervention development and testing. PURPOSE: This Occupational Therapy Doctoral Project entitled Teaching Intervention to Reduce Readmissions-Post Surgery (TIRR-PS) is a proposed program for an acute care hospital setting which: (a) described the problem of hospital readmissions among patients with a total hip or total knee arthroplasty, (b) investigated evidence and best practices for imparting knowledge and/or teaching skills to hospital administrators, healthcare professionals, occupational therapy staff, patients, and caregivers, (c) proposed an intervention based on empirically supported strategies and theoretical frameworks, (d) recommended activities to include as part of the program evaluation, the funding plan and the dissemination plan to promote this multi-level, multi-component pilot program. TIRR-PS will aim to reduce unplanned 30-day hospital readmissions and their associated healthcare costs. Unplanned readmissions are in part caused by inadequate education of hospital administrators, occupational therapy staff, patients, and caregivers. The TIRR-PS program will raise awareness about how to address common medical complication risks and promote the support of hospital administration for the education and skill building activities directed towards healthcare professionals with an emphasis on occupational therapy. CONCLUSION: TIRR-PS was designed for an acute care setting to reduce hospital readmission rates, to reduce healthcare costs, to improve patient quality of life, and to reduce the societal burden of unplanned hospital care. TIRR-PS is an innovative program designed to be comprehensive and to impart knowledge and skills to all relevant professionals in an acute care setting with a particular emphasis on the contribution of the OT profession. TIRR-PS, once evaluated, will provide a standardized, systematic approach to reducing unexpected hospitalizations post-TJA and shows promise for contributing to routine orthopaedic rehabilitative practice in acute care hospitals. This in turn will not only reduce healthcare costs, but will improve the post-surgery quality of life for patients with a recent total hip or total knee arthroplasty.

Low trauma hip fractures, due to bone fragility, are a major healthcare burden with serious consequences for individuals in terms of long-term morbidity and mortality; and also for society due to the high medical and care costs associated with these injuries. Because of the association with low bone mass, these fractures are particularly prevalent in elderly populations and are likely to become more common as longevity increases globally. Avoidance of these fractures is therefore an extremely important goal. Low bone mass, manifested in the conditions of osteopenia and osteoporosis, is the primary cause of bone fragility, and reductions in bone mass are the inevitable corollary of aging and menopause. Bone loss may be exacerbated by immobilisation and reduced weight-bearing activity, giving rise to the condition of disuse osteopenia. Immobilisation may itself be the result of low trauma leg fragility fractures that potentially causes further bone density loss. If this loss occurs at the hip, there is an increased risk for hip fracture as a sequela to the original injury. Osteoarthritis is also a condition strongly associated with aging that may necessitate knee arthroplasty as a last stage treatment, potentially causing a period of reduced mobility and weight-bearing activity following surgery. Leg fracture and knee replacement both present additional risk factors for hip fracture due to changes in muscle mass, gait and postural stability that may increase the risk of falls. This study aims primarily to investigate the effects of immobilisation on leg fracture and knee replacement patients, immediately following injury or surgery, in order to quantify bone and muscle loss and to monitor recovery over a one year period. A postmenopausal population were studied as they are already losing bone density systemically and may be at greater risk of further bone loss following immobilisation. Factors of activity, function, weight-bearing, pain, treatments, therapies, health perceptions and mental wellbeing, that potentially contribute to bone loss and recovery, were also investigated. Results from the study may provide information relating to increased future hip fracture risk and lead to treatment options to alleviate bone loss in these groups.

Discharge readiness following total knee replacement (TKR) has often been defined using quantitative factors, such as knee range of motion or walking a specified distance. These measurements fail to include other features that could impact readiness for discharge, such as social support or patient perceptions. Most patients have positive results following TKR surgery, however others experience negative outcomes such as falls, reduced functional performance, and hospital readmission. Readiness for returning home after TKR begins with pre-operative education to prepare patients for surgery and the post-operative phase. Health care providers must have a clear understanding of patients’ perceptions of readiness to return home after surgery. It is also essential to describe the current structure of pre-operative education nationally as a mechanism for better preparing patients to return home following knee replacement. This dissertation includes three studies that explore aspects of discharge readiness following TKR including patients’ perceptions of readiness for discharge as well as the structure of pre-operative education for TKR across the United States. The first study examined patients’ experiences preparing for discharge home from the acute care setting following TKR surgery. Results indicated that patients felt prepared overall for discharge and received appropriate supports for returning home after surgery, but some felt unprepared for certain aspects of recovery such as the amount of pain experienced in the post-operative phase. The second study surveyed health care providers who participated in pre-operative education before TKR to identify the current structure of education programs in the United States. This pilot study revealed that pre-operative education teams were commonly interprofessional with education being typically provided in a group format in a single session lasting between 1 and 1.5 hours. Verbal and written instruction were common delivery methods to provide education. The final dissertation study used mixed-methods to explore the current structure of pre-operative education for TKR in the United States with a large, national sample. Orthopedic nurses completed an online survey to describe their pre-operative education program. The majority of participants provided pre-operative education as part of interprofessional teams in either a group format or a format that included both group and individual education. Verbal instruction was the most common educational delivery method followed by written instruction. Most pre-operative education classes lasted between 1 and 1.5 hours, were delivered in a single session, and included a variety of topics. Ten orthopedic nurses were then interviewed and interview transcripts were analyzed qualitatively for common themes among participants. Participants expressed that pre-operative education was a significant component impacting patient outcomes following surgery. Interprofessional pre-operative education was valued by participants, but pragmatic factors were identified as barriers to the inclusion of other disciplines within these programs. Education programs were constantly evolving based on current evidence-based practice and changes to orthopedic protocols. Descriptions of pre-operative programs nationally combined with providers’ perceptions provides a strong basis for determining best practice to support better post-operative patient outcomes. This dissertation research culminated in recommendations for best practice as well as the creation of a model, the ICF-I-EDUCATE, which combines the International Classification of Health, Functioning and Disability (ICF), interprofessional practice, and the EDUCATE model for providing patient and family education. Research is needed to examine the ICF-I-EDUCATE model in clinical practice for patients with planned TKR.

Little is known about time to return to work (TRTW) following planned medical events. This study was a secondary analysis (n=94) to determine predictors of time to return to work following a total knee replacement for osteoarthritis. Significant predictors of delayed TRTW following a knee replacement: 1) use of workplace modifications (in 6wks vs 5 wks) and 2) poor physical function (in 7wks vs 6 wks). These findings have large implications for workers undergoing knee replacement, orthopedic clinicians, and occupational health nurses.

Tyrimo tikslas – įvertinti kineziterapijos pratimų ir keturgalvio šlaunies raumens elektrinės stimuliacijos poveikį moterų, kurioms endoprotezuotas kelio sąnarys, judėjimo funkcijai. Uždaviniai: 1. Nustatyti kineziterapijos pratimų poveikį moterų, kurioms endoprotezuotas kelio sąnarys, judesių amplitudei, raumenų jėgai, skausmo intensyvumui, kelio tinimui ir funkcinei būklei. 2. Nustatyti kineziterapijos pratimų, derinamų su raumenų elektrine stimuliacija, poveikį moterų, kurioms endoprotezuotas kelio sąnarys, judesių amplitudei, raumenų jėgai, skausmo intensyvumui, kelio tinimui ir funkcinei būklei. 3. Palyginti skirtingų kineziterapijos programų efektyvumą. Išvados: 1. Taikant kineziterapijos pratimus statistiškai reikšmingai padidėjo moterų, kurioms endoprotezuotas kelio sąnarys, operuotos kojos kelio judesių amplitudės, raumenų jėga, sumažėjo skausmo intensyvumas, kelio tinimas bei pagerėjo funkcinė būklė. 2. Taikant kineziterapijos pratimus ir keturgalvio šlaunies raumens elektrinę stimuliaciją statistiškai reikšmingai padidėjo moterų, kurioms endoprotezuotas kelio sąnarys, operuotos kojos kelio judesių amplitudės, raumenų jėga, sumažėjo skausmo intensyvumas, kelio tinimas bei pagerėjo funkcinė būklė. 3. Kineziterapijos pratimai, derinami su keturgalvio šlaunies raumens elektrine stimuliacija, labiau padidino blauzdą tiesiančių raumenų jėgą ir pagerino „Stotis ir eiti“ testo rezultatus nei vien kineziterapijos pratimai. Judesių amplitudei, skausmo intensyvumui, kelio... [toliau žr. visą tekstą] / The aim of the study: to evaluate the effect of physical therapy exercises and electrical stimulation of the quadriceps muscle on motor function in women after total knee replacement. Goals of the study: 1. To assess the effect of physical therapy exercises for range of motion, muscles strength, pain intensity, knee swelling and functional performance in women after total knee replacement. 2. To determine the effect of physical therapy exercises combined with neuromuscular electrical stimulation for range of motion, muscle strength, pain intensity, knee swelling and functional performance in women after total knee replacement. 3. To compare the effectiveness of different physical therapy programs. Coclusions: 1. Physical therapy exercises have significantly increased the knee range of motion, muscle strength, decreased pain intensity, the swelling of the knee and improved functional performance for women after total knee replacement surgery. 2. Physical therapy exercises with quadriceps muscle neuromuscular electrical stimulation have significantly increased the knee range of motion, muscle strength, decreased pain intensity, the swelling of the knee and improved functional performance for women after total knee replacement surgery. 3. Physical therapy exercises combined with quadriceps muscle neuromuscular electrical stimulation whilst compared to physical therapy exercises alone increased the strength of quadriceps muscle and results of “Timed up and go” test more. Both... [to full text]

This longitudinal, descriptive study based on Bandura's self-efficacy theory (1977), examined the effects of educational activities on self-efficacy and of self-efficacy on functional ability in everyday activities in clients undergoing elective, primary, unilateral, total knee arthroplasty (TKA). Educational activities included: attending a joint replacement class and a physical therapy session, performing exercises, and reading educational materials. Other sources of client information were also discussed. Self efficacy was assessed regarding confidence in ability to perform activities required for discharge home. Cronbach's alpha for the self-efficacy scale was .94 (pre-education) and .81 (post-education). Functional ability in everyday activities was operationalized as length of hospital stay, discharge placement, and perceived health status. Perceived health status was assessed using the three-scale Western Ontario McMasters University Osteoarthritis Index (WOMAC). Cronbach's alpha was: pain .85, joint stiffness .76, and physical function .94 (preoperatively); and pain .86, joint stiffness .80, and physical function .94 (postoperatively).Evidence was collected from a convenience sample of 31 participants: (a) when the process of scheduling surgery began; (b) before surgery, after the client had opportunities to participate in educational activities, and (c) approximately six weeks after surgery. The orthopedic surgeon and professional staff reviewed instruments for validity. Five clients reviewed the questionnaires for understandability and readability. Data were analyzed using Pearson r correlation coefficients, independent samples t-tests, analyses of variance and chi-square tests. An alpha level of .05 was designated as significant.Higher self-efficacy scores were associated with more expected benefits, previous TKA, and greater pain relief. Lower self-efficacy scores correlated with greater improvement in self-efficacy. Shorter lengths of hospital stay were associated with greater joint stiffness reduction, younger age and previous TKA. Discharge home was associated with younger age and living with someone else. Participants that were "very sure" of the need for TKA exhibited higher self-efficacy scores than participants that were "unsure". Improved outcomes were not associated with any one type of educational activity.This study highlighted the need for further refinement of context sensitive self-efficacy instruments, more sophisticated means of assessing the impact of an increasing array of information sources and more longitudinal studies with larger sample sizes. / Department of Educational Leadership