Abstract: Objective: To compare the long-term viability of percutaneously injected crushed auricular cartilage to surgically implanted cartilage in the rabbit. Methods: Auricular cartilage was harvested bilaterally in 10 New Zealand white rabbits. A 1 cm2 cartilage graft was harvested and implanted surgically on the upper nasal dorsum. The remaining cartilage was crushed and percutaneously injected on the lower nasal dorsum. Volume and mass of each graft were compared between pre-implantation and after 3 months of observation. A histological study was conducted to evaluate chondrocyte viability and degree of fibrosis on the grafts. Results: Mass and volume remained similar for surgically implanted cartilage grafts. Mass and volume diminished by an average of 47% and 40% respectively after 3 months for the injected crushed cartilage grafts. Chondrocyte viability was an average of 25% lower in the injected grafts. Conclusion: Cartilage injection is a promising technique that must be refined to increase long term chondrocyte viability. Developing an appropriate injection apparatus would improve this technique. / Résumé : Objectif: Comparer la viabilité à long-terme de cartilage auriculaire broyé injecté de façon percutanée au cartilage implanté chirurgicalement chez le lapin Méthodes: Prélèvement de cartilage auriculaire bilatéralement chez 10 lapins blancs « New Zealand ». Pour chaque lapin, une greffe de cartilage de 1 cm2 fut prélevée et implantée chirurgicalement au niveau du dorsum nasal supérieur. Le reste du cartilage fut broyé puis injecté de manière percutanée sur le dorsum nasal inférieur. La masse et le volume de chaque greffon furent mesurés lors de la chirurgie initiale et 3 mois plus tard. Une étude histologique a été entreprise afin de comparer la viabilité des greffons et le degré de fibrose. Résultats: La masse et le volume des greffons de cartilage entier sont demeurés semblables suite à l’implantation. La masse et le volume des greffons de cartilage injecté ont diminué en moyenne de 47% et 40% respectivement suite à l’implantation. L’analyse histologique a démontré une diminution moyenne de 25% de la viabilité chondrocytaire pour les greffons de cartilage injecté. Conclusion: L’injection de cartilage est une technique prometteuse devant être raffinée pour augmenter la viabilité chondrocytaire à long-terme. Le développement d’un instrument d’injection approprié faciliterait la technique.

INTRODUCTION: The association of Sleep-Related Movement Disorders (SRMDs) such as Restless Legs Syndrome (RLS) and Periodic Limb Movements (PLMs) with cerebrovascular disease is underexplored. Emerging evidence links them to vascular disease, for which white matter hyperintensities (WMHs) are a well-recognized biomarker. METHODS: We conducted a cross-sectional hospital-based observational study in which high-risk TIA and minor stroke patients were assessed for vascular risk factors, WMHs and polysomnography-determined sleep variables. RESULTS: Ninety-seven patients were enrolled, of whom 44 completed polysomnography. Twenty-five percent had RLS, which was associated with lower quality of life. Independent of the effect of classical vascular risk factors, PLMs (but not RLS) were associated with WMHs on linear regression analyses (p=0.016). CONCLUSIONS: SRMDs are prevalent after minor stroke/TIA. RLS is associated with poor quality of life, while PLMs are associated with WMHs. Whether PLMs are implicated in the pathogenesis of WMHs or whether WMHs exacerbate PLMs remains uncertain.

Objective: To complete a cost-minimization analysis (CMA) of the cost of sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND) in the management of early-stage breast cancer (ESBC) in a hypothetical Ontario hospital setting. Methods: Decision-analysis modeling, with a decision-tree and Markov states, was used to estimate hospital costs for the two treatment options. The model was populated with data from the literature and costs from the Ontario Case Costing Initiative, a publicly accessible, government-sponsored, costing database. Model variability and parameter uncertainty were quantified by probabilistic sensitivity analysis (PSA). Results: The SLNB treatment algorithm was cost-minimizing compared to the ALND-only treatment option. The costs of treating postoperative complications did not contribute to the incremental average cost. Conclusion: A treatment algorithm that involves SLNB as the initial axillary-staging procedure in the setting of ESBC offers a cost-savings over the ALND-only option. This result is generalizable to all Ontario hospitals.

The current study characterizes the mechanical and biodegradation properties of a polycarbonate polyurethane (PU) electrospun nanofiber scaffold intended for use in the growth of a tissue engineered annulus fibrosus (AF) intervertebral disc component. Both the tensile strength and initial modulus of aligned scaffolds were higher than those of random scaffolds and remained unaffected during a 4 week biodegradation study, suggesting a surface-mediated degradation mechanism. The resulting degradation products were non-toxic. Confined compressive mechanical force of 1kPa, was applied at 1Hz to in vitro bovine AF tissue grown on the scaffolds to investigate the influence of mechanical force on AF tissue production, which was found to decrease significantly at 72 hours relative to 24 hours, independent of any effects from mechanical forces. Overall, the consistent rate of PU degradation, along with mechanical properties comparable to those of native AF tissue, and the absence of cytotoxic effects, make this polymer suitable for further investigation for use in tissue-engineering the AF.

Background: Total hip replacement (THR) with post-operative surveillance is recommended for debilitating osteoarthritis (OA). Using self-reported pain, function or walking performance is one alternative to address increasing surveillance demands. Objective: A cross-sectional cohort study to evaluate the associations of pain, function and performance with two radiographic markers of potential THR failure. Participants: 110 patients, median 6 years after THR surgery for OA. Methods: Questionnaires assessed demographics, co-morbidity, arthritis severity, pain, pain catastrophizing, and functional status. Performance was measured using the six minute walk test. THR outcome was assessed radiographically. Results: Few patients had pain, functional impairment or radiographic markers of potential THR failure. A larger percentage of patients with some intermittent pain (10.7 versus 8.6%) and pain iii after walking performance (40.0 versus 27.6%) had higher wear, but these differences were not significant. Conclusion: Measures of pain are potentially important for larger studies aiming to develop alternative methods of post-operative surveillance.

The global burden of injury is severely underappreciated and disproportionately affects low-income countries. With timely, appropriate orthopaedic treatment disability and mortality can be prevented, yet appropriate health resources are seldom available. Without orthopaedic medical devices (OMDs), quality of orthopaedic care suffers and the burden of preventable injury is exacerbated. A qualitative case study of 45 key informant interviews was conducted in Uganda to explore accessibility of OMDs, such as plaster, external fixators and implants. Data analysis elicited four major themes as barriers preventing access to OMDs in Uganda: 1) Poor leadership in government and corruption; 2) inadequate human resources; 3) inefficient and insufficient health care infrastructure; and 4) high costs of OMDs and poverty. Potential solutions for improving access to orthopaedic care were categorized as policies prioritizing orthopaedic services, training more orthopaedic specialists and creating incentives for them to work in underserviced areas, and innovative strategies funding for orthopaedic services.

Clostridium difficile colitis (CDC) is associated with a higher risk of acute death among hospitalized ulcerative colitis (UC) patients. However, the risk of colectomy with CDC in these patients has varied across studies. No study has assessed the long-term health impact of CDC in UC patients. Therefore, the present study evaluated the impact of CDC on five-year health outcomes of hospitalized UC patients based on Ontario health administrative data. No overall association was observed between CDC and five-year risks of colectomy or death in overall cohort. However, patients who were discharged from hospital without undergoing colectomy demonstrated marginally higher five-year risks of colectomy and hospital re-admission. Mortality risk and length of stay during index hospitalization were also higher in patients with CDC. Analysis of a parallel cohort of UC patients derived using a published case definition corroborated most of these results, but demonstrated a higher five-year mortality risk with CDC.

Aims: To investigate the natural history of CHC, estimate the disease burden of CHC, and assess the cost-effectiveness of screening for CHC among immigrants living in Canada. Methods: A retrospective cohort study compared the prognosis of CHC between immigrant patients and native-born patients who had advanced fibrosis. A cross-sectional study assessed the association between obesity and hepatitis C viremia. The disease burden of CHC among immigrants was estimated through Markov cohort model. The cost-effectiveness of screening for CHC was assessed among immigrants. Results: The retrospective cohort study including 318 patients demonstrated that immigrant patients had significantly higher risk of hepatocellular carcinoma than Canadian-born patients (p=0.005). The hazard ratio associated with ‘immigrant’ for hepatocellular carcinoma in multivariate Cox proportional-hazards analyses reduced to the least and non-significant (p=0.318) after adjusting age and type 2 diabetes. The prevalence of obesity in 1118 individuals tested positive for hepatitis C antibody was 28.8%. Multiple regression analyses and propensity score methods suggested a significant association between obesity and hepatitis C viremia. The disease burden study estimated that immigrants with CHC had much shorter average life years (26.9 years vs. 39.1 years) and quality adjusted life years (20.6 years vs. 32.4 years) than the age matched immigrants without CHC. The cost-effectiveness study indicated that screening for CHC among immigrants from 183 countries (72.1% of immigrant population in Canada) had an incremental cost-effectiveness ratio less than $50,000 per quality adjusted life year gained. Conclusion: Immigrant patients with CHC could have a higher risk of HCC than native-born patients. The significant association between obesity and hepatitis C viremia could explain the observed high prevalence of type 2 diabetes in patients with CHC. CHC reduces the average life expectancy of immigrants with CHC more than 10 years. Screening for CHC is cost-effective among over 70% of immigrants living in Canada.

Purpose: Patients living with advanced heart failure experience dyspnea, fatigue, poor quality of life, depression and cognitive impairment which may threaten their ability to provide informed consent to undergo heart transplant (HTx) or mechanical support (LVAD). Using qualitative and quantitative methods, we asked how patients with advanced heart failure make decisions regarding HTx and LVAD. The variables chosen to reflect the elements of consent included quality of life and symptom severity (voluntariness), depression and cognitive impairment (capacity) and treatment preferences (decision-making). Methods: 76 patients enrolled in the quantitative arm completed the Minnesota Living with Heart Failure Questionnaire; Visual Analog scales for dyspnea, fatigue and overall health; Beck Depression Inventory; Montreal Cognitive Assessment; Standard Gamble and Time Tradeoff. Qualitative methods were used to discover concepts, relationships and decision-making processes described by 17 of the 76 patients considering HTx and LVAD. Results: Patients reported poor quality of life and high symptom severity scores which compelled them to consider surgery as a way to relieve unpleasant symptoms and improve quality of life. Although 30% of patients had evidence of depression and/or cognitive impairment, no patient was deemed incapable of decision-making. Patients were willing to take considerable risk (35%) and trade considerable time (4months) to improve their health. While heart failure-related concepts were important to the decision, entrustment emerged as the meaningful process for decision-making. Conclusions: Patients who participated in this study were capable of decision-making and understood the risks associated with the surgery. Voluntariness was diminished by disease but not absent, and decisions were free of coercion. These results suggest the entrustment model of decision-making is the dominant process for patients considering high-risk surgical procedures and meets criteria for informed consent. Understanding the process of decision-making will help clinicians support and enable treatment decisions made by patients living with advanced heart failure.

Objective: To complete a cost-minimization analysis (CMA) of the cost of sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND) in the management of early-stage breast cancer (ESBC) in a hypothetical Ontario hospital setting. Methods: Decision-analysis modeling, with a decision-tree and Markov states, was used to estimate hospital costs for the two treatment options. The model was populated with data from the literature and costs from the Ontario Case Costing Initiative, a publicly accessible, government-sponsored, costing database. Model variability and parameter uncertainty were quantified by probabilistic sensitivity analysis (PSA). Results: The SLNB treatment algorithm was cost-minimizing compared to the ALND-only treatment option. The costs of treating postoperative complications did not contribute to the incremental average cost. Conclusion: A treatment algorithm that involves SLNB as the initial axillary-staging procedure in the setting of ESBC offers a cost-savings over the ALND-only option. This result is generalizable to all Ontario hospitals.