Lymphocyte transformation test reveals low prevalence of true metal hypersensitivity among pre-operative total knee arthroplasty patients.

PURPOSE: The aims of this study were to determine the prevalence of metal hypersensitivity, and identify pre-operative factors which could predict susceptibility to hypersensitivity reactions among patients scheduled for primary total knee arthroplasty (TKA). The present study used a testing method consistent with the recognised biological response to metals. METHODS: A prospective cross-sectional analysis of 220 patients was conducted. All patients received a testing protocol using lymphocyte transformation test to evaluate reactivity to possible contents of orthopaedic implants. Test response is interpreted as stimulation index (SI) values. A comprehensive questionnaire was used to evaluate prior exposure. Patients were categorised according to SI values and the odds ratios (OR) were calculated as comparative effect measure for each predetermined prior exposure factor. RESULTS: The prevalence of metal sensitivity response was 28% (n = 61) among patients with susceptibility to at least one agent (SI = 2 to 4.9), and 3.2% (n = 7) among patients with true hypersensitivity (SI ≥ 5). The population-weighted prevalence, adjusted for sampling weights of symptomatic knee osteoarthritis, was SI ≥ 5 = 4.7% (95% CI 0.4-11.8%) and SI ≥ 2 = 35.2% (95% CI 24.8-48.6%). Stimulation index levels of response to materials were markedly varied with the highest being aluminium. Female sex, smoking history, cutaneous reaction to jewellery, occupational exposure, and dental procedures were among factors shown to increase the odds of having higher reactivity response to tested metals. Nevertheless, patients with well-functioning prior contralateral TKA did not appear at greater risk of having either sensitivity or susceptibility with odds ratio (OR) = 0.2 (95% CI 0.01-3.2), p: NS and OR = 0.6 (95% CI 0.3-1.2), p: NS, respectively. Prior positive patch test was neither predictor of susceptibility to hypersensitivity OR = 1.2 (95% CI 0.6-2.6) p: NS nor predictor of true hypersensitivity OR = 0.7 (95% CI 0.08-6.1), p: NS. CONCLUSION: Among patients scheduled for primary TKA with no prior clinical features of metal allergy the prevalence of true hypersensitivity to at least one metal is just over 3%. Patients are likely to encounter a material to which they have pre-existing susceptibility to hypersensitivity. With certain prior exposure factors, there was increased susceptibility to metal hypersensitivity reaction evoking an acquired condition. LEVEL OF EVIDENCE: Level II, prospective cross-sectional study.

Opposed attentional hemi-bias on a visuoconstructive task in children with severe hyperactivity versus severe inattention.

Twenty six empirical investigations have now established that children and adults with DSM-defined Attention deficit/Hyperactivity disorder (ADHD) of the Hyperactive type (ADHD-H) or, more commonly, Combined Hyperactive/Inattentive types (ADHD-C) manifest a small but significant visual attentional bias to the right side (left subclinical neglect), consistently suggesting the existence of a subtle right hemisphere dysfunction or hemispheric imbalance in hyperactive people. Only one research team has investigated and compared the DSM-defined Inattentive subtype (ADHD-I) to the Hyperactive subtype (ADHD-H), confirming that line bisection is biased to the right in ADHD-H and discovering that it is biased to the left in ADHD-I. We aimed to test whether a similar crossed double dissociation would extend to Rey's Complex Figure Copy Task (RCF-CT), a simple visuospatial-constructive task. Clinical files of 205 juvenile clients from 6 to 16 years of age from a neuropsychological private clinic specialized in ADHD were analysed. Extreme scores on the Connors-3 Hyperactivity vs Inattention Parent Rating scales associated, respectively, with significant rightward and significant leftward emplacement of the drawing on the page on the RCF-CT. These results replicate previous findings and extend the "energetics" model of hemispheric specialization.

LARS synthetic ligaments for the acute management of 111 acute knee dislocations: effective surgical treatment for most ligaments.

PURPOSE: The purpose of this study was to describe the longitudinal outcomes of acute repair and augmentation for the reconstruction of dislocated knees, using LARS synthetic ligaments. METHODS: Patients with a knee dislocation surgically treated using LARS synthetic ligament augmentation, with a minimum follow-up of 24 months, were enrolled between 1996 and 2014. Range of motion, Lachman, pivot shift, posterior drawer, step off sign, valgus, varus, KT-1000 arthrometer, Telos technique, IKDC, Lysholm, Tegner, and Meyers scores were obtained every 2 years up to 10 years. RESULTS: Median age was 32.1 years (IQR 23.2-43.3) at time of surgery. Median time from trauma to surgery was 9 days and mean follow-up time was 6.6 years. Median questionnaire scores were: Lysholm 79.5 (IQR 65.0-89.0), Tegner 4.0 (IQR 3.7-6.0), Meyers 3.0 (IQR 3.0-4.0), and mean IKDC was 63.8 (SD 18.9). Median flexion and extension of the injured knee was 124° (IQR 115-129.5) and 0° (IQR - 5 to 0), respectively. Median KT-1000 differential was 0.7 mm (IQR 0.1-3.1) for ACL and 0.9 mm (IQR 0.2-1.4) for PCL. Mean differential for Telos was 2.5 mm (SD 5.8) for ACL, 4 mm (IQR 2-6.3) for PCL 30°, and 8.2 mm (SD 4.4) for PCL 90° (consistent with PCL laxity). More than 90% of patients had good anterior articular stability and > 60% of patients had good posterior articular stability. CONCLUSIONS: Acute repair and augmentation of knee dislocations with LARS synthetic ligaments resulted in satisfactory outcomes for the ACL and collateral structures. Telos stress radiography showed PCL laxity in more than half of cases despite low laxity results with KT-1000. The perception of patients about knee function was sustained in time. LEVEL OF EVIDENCE: IV.

Atypical left-right balance of visuomotor awareness in adult ADHD (combined type) on a test of executive function.

Significant left subclinical hemi-neglect or "hemi-unawareness" in juvenile and adult ADHD has been reported many times. However, this literature has never been thoroughly reviewed, and is generally ignored in neuropsychological accounts of ADHD. The purposes of the present report were (1) to introduce a systematic review of this literature and (2) to prospectively test whether adults with ADHD (combined type) would present left hemi-unawareness measurable on a test of executive function commonly used with children and adults with ADHD, the Colour-Word Interference Test of the Delis-Kaplan Executive Functions System. This test requires participants to discriminate unusual stimulus characteristics by stating words aloud while visually scanning plates comprising either 50 colour patches or 50 words. A total of 28 ADHD adults (combined type) and 30 IQ-, age-, and gender-matched controls completed the task. The ADHD group manifested a significantly higher proportion of errors on the left than right sides of the plates. This atypical left-right balance was related to severity of the ADHD according to the Conners' Adult ADHD Rating Scale (CAARS) as well as to several other indicators from the Continuous Performance Test-II.

Clinical and quality-of-life outcomes of a combined synthetic scaffold and autogenous tissue graft procedure for articular cartilage repair in the knee.

BACKGROUND: Injuries to the articular cartilage of the knee often fail to heal properly due to the hypocellular and avascular nature of this tissue. Subsequent disability can limit participation in sports and decrease quality of life. Subchondral bone perforations are used for the treatment of small defects. Filling out the central portion in larger lesions becomes difficult, and scaffolds can be used as adjuvants, providing a matrix onto which the defect can be filled in completely. Also, autogenous cartilage grafts can be combined, acting as an inducer and improving healing quality, all in a single procedure. METHODS: This observational study evaluated the clinical and quality-of-life outcomes of patients with articular cartilage lesions of the knee undergoing repair via a microfracture technique combined with a synthetic scaffold and autogenous cartilage graft, with transosseous sutures and fibrin glue fixation, at 12 months of follow-up. Secondarily, it assessed whether combined procedures, previous surgical intervention, traumatic aetiology, lesion location, and age affect outcomes. The sample consisted of adult patients (age 18-66 years) with symptoms consistent with chondral or osteochondral lesions, isolated or multiple, ICRS grade III/IV, 2-12 cm2 in size. Patients with corrected angular deviations or instabilities were included. Those with BMI > 40 kg/m2, prior total or subtotal (> 30%) meniscectomy, second-look procedures, and follow-up < 6 months were excluded. Pain (VAS), physical activity (IKDC), osteoarthritis (WOMAC), and general quality of life (SF-36) were assessed. RESULTS: 64 procedures were included, comprising 60 patients. There was significant improvement (P < 0.05) in VAS score (5.92-2.37), IKDC score (33.44-56.33), and modified WOMAC score (53.26-75.93) after surgery. The SF-36 showed significant improvements in the physical and mental domains (30.49-40.23 and 46.43-49.84 respectively; both P < 0.05). CONCLUSIONS: Combination of microfractures, autogenous crushed cartilage graft, synthetic scaffold, and transosseous sutures with fibrin glue provides secure fixation for treatment of articular cartilage lesions of the knee. At 12-month follow-up, function had improved by 20 points on the IKDC and WOMAC, and quality of life, by 10 points on the SF-36. Age > 45 years had a negative impact on outcomes.

Randomized controlled trial of virtual reality and hybrid simulation for robotic surgical training.

OBJECTIVE: To evaluate if two commonly used laparoscopic simulators could be adapted and used successfully for the robotics platform in a laparoscopic and robotic naïve medical student population. MATERIALS AND METHODS: We identified two widely validated laparoscopic simulation programs, LapSim(®) (Surgical Science Sweden AB), and ProMIS(®) (Haptica, Ireland)for inclusion in the study. The McGill Inanimate System for Training and Evaluation of Laparoscopic Skills(®) task set was used for ProMIS, and adapted for the DaVinci(®) console (Intuitive Surgical, Inc., Sunnyvale, CA, USA) robotic platform. We then randomized 20 naïve medical students to receive training on either LapSim or ProMIS, both or neither, and evaluated them before and after training. RESULTS: When the groups were compared at baseline, there were no statistical differences in mean scores amongst the groups in univariate analysis (α= 0.05). When comparing mean scores within groups before and after training sessions, statistically significant performance enhancement in all four robotic tasks were identified in the groups receiving dual training. CONCLUSION: We have shown that the use of ProMIS hybrid and LapSim virtual reality (VR) simulators in conjunction with each other can considerable improve robotic console performance in novice medical students compared with hybrid and VR simulation alone.

Trabecular metal used for major bone loss in acetabular hip revision.

The purpose of this study was to evaluate the outcome of trabecular metal (TM) acetabular components used in revision hip arthroplasty with major bone deficiency. We retrospectively reviewed the records of 46 patients undergoing revision hip arthroplasty with severe acetabular bone loss. Clinical outcomes were assessed using Harris Hip Score, Western Ontario and McMaster Universities, and Short-Form 12. Mean follow-up was 50 months. All patients had Paprosky type IIc or III acetabular bone deficiency. Major complications included 1 infection, 2 dislocations, and 1 arterial bleeding. Average Harris Hip Score was 78.2. Short-Form 12 scores were within population-based age-matched averages. Western Ontario and McMaster Universities scores were mainly in the 2 lowest disability categories. Porous tantalum shows promising results in revision arthroplasty with severe acetabular bone loss.

Evaluation of reconstructive surgery using artificial ligaments in 71 acute knee dislocations.

This retrospective study assessed the results of 71 patients with knee dislocations who underwent acute combined repair and reconstruction using Ligament Advancement Reinforcement System (LARS) artificial ligaments between June 1996 and May 2008 with a follow-up between two and eight years. The outcome measures used were the Lysholm score, the International Knee Documentation Committee form (IKDC 2000), the Tegner activity level score, the Meyers ratings, Telos stress radiography, range of motion and clinical knee stability testing. When comparing high- versus low-energy dislocations and knee dislocation (KD) II/III versus KD IV injuries, a better Lysholm score for the knee dislocation (KD) II/III group was found compared with the KD IV group. The subjective and objective findings from our study are satisfactory and comparable with the results of other studies of knee dislocations. Our findings suggest that with a mean follow-up of 54 months, acute combined repair and reconstruction with LARS ligaments is a valid alternative for treating knee dislocations.

Trajectories of Follow-up Compliance in a Fracture Liaison Service and Their Predictors: A Longitudinal Group-Based Trajectory Analysis.

INTRODUCTION/OBJECTIVES: Identification of groups of patients following similar trajectories of time-varying patient characteristics are often of considerable clinical value. This study provides an example of how the identification of trajectory groups of patients can be useful. METHODS: Using clinical and administrative data of a prospective cohort study aiming to improve the secondary prevention of osteoporosis-related fractures with a Fracture Liaison Service (FLS), trajectory groups for visit compliance over time (2-year follow-up) were predicted using group-based trajectory modeling. Predictors of trajectory groups were identified using multinomial logistic regressions. RESULTS: Among 532 participants (86% women, mean age 63 years), three trajectories were identified and interpreted as high followers, intermediate followers, and low followers. The predicted probability for group-membership was: 48.4% high followers, 28.1% intermediate followers, 23.5% low followers. A lower femoral bone mineral density and polypharmacy were predictors of being in the high followers compared to the low followers group; predictors for being in the intermediate followers group were polypharmacy and referral to a bone specialist at baseline. CONCLUSIONS: Results provided information on visit compliance patterns and predictors for the patients undergoing the intervention. This information has important implications when implementing such health services and determining their effectiveness.

Patient Healthcare Trajectory and its Impact on the Cost-Effectiveness of Fracture Liaison Services.

This study aimed to assess the cost-utility of a Fracture Liaison Service (FLS) with a systematic follow-up according to patients' follow-up compliance trajectories. The Lucky Bone™ FLS is a prospective cohort study conducted on women and men (≥40 years) with fragility fractures. Dedicated personnel of the program identified fractures, investigated, treated, and followed patients systematically over 2 years. Groups of follow-up compliance trajectories were identified, and Markov decision models were used to assess the cost-utility of each follow-up trajectory group compared to usual care. A lifetime horizon from the perspective of the healthcare payer was modeled. Costs were converted to 2018 Canadian dollars and incremental cost-utility ratios (ICURs) were measured. Costs and benefits were discounted at 1.5%. A total of 532 participants were followed in the FLS (86% women, mean age of 63 years). Three trajectories were predicted and interpreted; the high followers (HFs, 48.4%), intermediate followers (IFs, 28.1%), and low followers (LFs, 23.5%). The costs of the interventions per patient varied between $300 and $446 for 2 years, according to the follow-up trajectory. The FLS had higher investigation, treatment, and persistence rates compared to usual care. Compared to usual care, the ICURs for the HF, IF, and LF trajectory groups were $4250, $21,900, and $72,800 per quality-adjusted life year (QALY) gained, respectively ($9000 per QALY gained for the overall FLS). Sensitivity analyses showed that the HF and IF trajectory groups, as well as the entire FLS, were cost-effective in >67% of simulations with respect to usual care. In summary, these results suggest that a high-intensity FLS with a systematic 2-year follow-up can be cost-effective, especially when patients attend follow-up visits. They also highlight the importance of understanding the behaviors and factors that surround follow-up compliance over time as secondary prevention means that they are at high risk of re-fracture. © 2020 American Society for Bone and Mineral Research (ASBMR).

Performance of a Fracture Liaison Service in an Orthopaedic Setting: A Report of Key Indicators and Improvement of Longitudinal Outcomes.

BACKGROUND: Many Fracture Liaison Services (FLSs) have been successfully implemented, but very few incorporate systematic longitudinal follow-up. The objective of this study was to report on the performance of such an FLS using key performance indicators and longitudinal clinical outcomes. METHODS: An FLS was implemented in 2 outpatient orthopaedic clinics. Men and women who were ≥40 years of age and had a recent fragility fracture were recruited. Participants were evaluated, treated when appropriate, and systematically followed over a 2-year period. Clinical data including chart review and questionnaires were collected. Medical services and hospitalization claims data were retrieved from administrative databases. The primary outcomes were the following key performance indicators: the numbers of investigated and treated patients, follow-up attendance, and the incidence of subsequent fractures. Secondary outcomes were the changes in bone turnover markers and quality of life, physical capacity, and pain scores between baseline and follow-up visits. RESULTS: A total of 532 subjects with a mean age of 63.4 years were recruited; 85.7% were female. Bone mineral density results were collected for 472 subjects (88.7%) and a prescription for anti-osteoporosis medication was given to 86.6% of patients. Overall, 83.6% of patients attended at least 1 follow-up visit. The subsequent fracture incidence rate was 2.6 per 100 person-years (23 fractures). The mean level of type-I collagen C-telopeptide (CTX-1), a bone resorption marker, decreased >35%. Clinically important improvements of functional capacity scores (by 14.4% to 63.7%) and pain level (by 19.3% to 35.7%) were observed over time; however, the increase in quality-of-life scores was not clinically important (by 3% to 15.2%). CONCLUSIONS: In this FLS, the rates of investigation, treatment, and participation were >80% over a 2-year period. The subsequent fragility fracture incidence rate was <3 per 100 person-years. These results suggest that an intensive FLS model of care, with a systematic longitudinal follow-up, is effective. A randomized controlled trial is needed to support these results. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Post unilateral lesion response biases modulate memory: crossed double dissociation of hemispheric specialisations.

We propose that what appears to be hemispheric specialisation in the memory domain, as indexed by effects of unilateral brain lesions, is to a great extent explainable as response bias: left hemisphere lesions result in an omissive response bias or error pattern whereas right hemisphere lesions result in a commissive response bias or error pattern. To test this prediction a group of 40 non-confabulatory cases with a verbal and non-verbal retention deficit (hypomnesia), subsequent to a unilateral lesion, was assembled from the literature. A group of non-amnesic cases with confabulation, paramnesia, false memories or memory-laden hallucination (dysfunctional hypermnesia), due to a unilateral lesion, was also assembled from the literature (N=72). Most of the hypomnesic patients had left hemisphere lesions (73%, p<.005, two tailed) while most of the hypermnesic patients had right hemisphere lesions (78%, p<.0005, two tailed). This crossed double dissociation held good despite statistical control of the lesion's locus within the hemisphere, its size or its aetiology, presence of aphasic symptoms, psychiatric comorbidity, the patient's age, gender, or hand preference, and several other potentially confounding variables.

Persistence and compliance to osteoporosis therapy in a fracture liaison service: a prospective cohort study.

Persistence and compliance to osteoporosis medications aiming to prevent fragility fractures are essential for fracture prevention, but are suboptimal in the population. A Fracture Liaison Service with a systematic follow-up led to ongoing therapy and optimal drug compliance for more than half of treated patients over 2 years. PURPOSE: Fracture Liaison Services (FLS) have the potential to improve persistence and compliance to osteoporosis therapy. We aimed to assess patterns of drug use in a high-level intervention FLS. METHODS: Women and men (> 40 years) with a fragility fracture were recruited in a FLS, where osteoporosis therapy was prescribed if appropriate. Based on claims data, patients who filled their prescription in the 3-month period following baseline were selected. The 1- and 2-year persistence rates were measured using survival analysis. In non-persistent subjects, 1-year treatment re-initiation was measured. The 1- and 2-year compliance levels were measured, using the proportion of days covered (PDC > 80% = compliant). Regression analyses were performed to identify predictors of non-persistence/compliance. RESULTS: Out of 332 subjects with complete drug insurance coverage, 297 (89.5%) were prescribed osteoporosis therapy by the FLS, and 275 (92.6%) were dispensed. Two hundred sixty participants (86.9% female; mean age 65.6 years) were selected for having filled a prescription inside 3 months after baseline. The 1- and 2-year persistence rates were 66.4% and 55.6%, respectively. Treatment re-initiation was observed in 56% of non-persistent patients. PDC was > 80% in 64.2% for 1 year and 62.5% for 2 years. Older and younger age, smoking, higher spine bone mineral density, lower major FRAX risk, and missing follow-up visits were predictors of non-persistence and/or non-compliance. CONCLUSIONS: After 2 years in a high-level intervention FLS, more than half the treated participants were persistent and compliant to treatment. Comparative effectiveness studies must be undertaken to determine whether this intervention is an improvement over usual care.

Rationale, study design, and descriptive data of the Lucky Bone™ Fracture Liaison Service.

The study design of a multidisciplinary Fracture Liaison Service (2-year follow-up) aiming to optimize fragility fracture management in an outpatient setting is presented. Patient characteristics, investigation, and treatment initiation data at baseline were recorded. Results corroborate the care gap in osteoporosis management, reinforcing the need for secondary fracture prevention programs. PURPOSE: This paper describes the study design, implementation, and baseline characteristics of a multidisciplinary Fracture Liaison Service (FLS) in Quebec (Canada). METHODS: A FLS was implemented as a prospective cohort study. After identification, fracture risk was assessed and patients were started on treatment or referred, according to guidelines and risk assessment. Thereafter, patients were systematically followed over 2 years. Clinical data (fractures, bone density, blood testing (bone turnover markers), quality of life, physical disability) as well as administrative data (pharmacological, health services, hospitalization) was collected. Baseline descriptive data was analyzed and presented. RESULTS: Of 542 recruited participants, 532 underwent baseline assessment (85.7% female, mean age 63.4 years). Overall, 29.7% of participants either withdrew from the study or were lost to follow-up. Almost 27% were referred to a specialist, while > 70% received anti-osteoporosis medication prescriptions through the FLS at baseline. Mean femoral T-score was - 1.6 ± 1.0 and vertebral T-score was - 1.7 ± 1.4. Nearly 19% of subjects reported being under anti-osteoporosis medication at the time of incident fracture. Thirty-three percent of participants reported a prior fracture history, of which 29.7% reported being given anti-osteoporosis therapy. Most fracture sites were to the wrist and ankle, while < 19% were hip/femur or vertebral fractures. CONCLUSIONS: These results highlight the important care gap in fragility fracture management and reinforce the need for secondary fracture prevention programs. This prospective study will allow the evaluation of key performance indicators for outpatient clinic-based FLS, such as medication usage, by combining prospective clinical and administrative data.

Hybrid augmented reality simulator: preliminary construct validation of laparoscopic smoothness in a urology residency program.

PURPOSE: We examined the usefulness, reliability and applicability of the smoothness metric of the ProMIS hybrid simulator (Haptica, Dublin, Ireland) for a urology residency program. MATERIALS AND METHODS: A total of 15 urology residents divided into junior and senior cohorts were followed prospectively for 6 training sessions. Validated McGill Inanimate System for Training and Evaluation of Laparoscopic Skills (MISTELS) laparoscopic tasks were used. The ProMIS hybrid simulator smoothness parameter, a unit-free metric of movement efficiency, was recorded using 3-dimensional visual tracking technology. Results were compared between cohorts at the midpoint and end of the defined training sessions. End of study junior means were also retrospectively compared to senior mid training means. Statistical significance was determined using the Mann-Whitney U test (alpha = 0.05). RESULTS: Statistically significant differences between 8 junior and 7 senior cohorts were measured in all MISTELS tasks. A statistically significant performance variation was also detected at the mid and end testing times. When juniors and seniors were compared between sessions 1 and 3, and 4 and 6, statistically significant performance improvements were noted. Lastly, statistical differences were also maintained when mid session senior means were compared to end of session junior means. A 38% improvement in task completion in the senior cohort as well as a 10-fold decrease in variance was observed compared to a 12% improvement in juniors, indicating greater efficiency of movement in seniors. CONCLUSIONS: The laparoscopic smoothness metric in the hybrid simulator demonstrated construct validity by effectively differentiating between experienced and novice urology residents using validated MISTELS tasks. The outcome suggests that the hybrid simulator smoothness metric is a valuable asset in residency programs for preparatory training for live operative experience, allowing improved trainee assessment.

Incidence of symptomatic venous thromboembolism in 2372 knee and hip replacement patients after discharge: data from a thromboprophylaxis registry in Montreal, Canada.

BACKGROUND: Low-molecular-weight heparin (LMWH) is a recommended anticoagulant for thromboprophylaxis after major orthopedic surgery. Dabigatran etexilate is an oral anticoagulant recognized as noninferior to LMWH. We aimed to assess the incidence of symptomatic venous thromboembolic events (VTEs) after discharge in patients who underwent joint replacement, using a hospital registry. PATIENTS AND METHODS: Patients who underwent total knee and hip arthroplasty between September 2011 and March 2015 were selected. Subcutaneous enoxaparin (30 mg twice daily) was given during hospitalization. At discharge, patients received either enoxaparin 30 mg twice daily/40 mg once daily or dabigatran 220 mg/150 mg once daily. Patients were seen or called at 2, 6, and 12 weeks after surgery. Outcomes were the number of VTEs, including deep venous thrombosis, pulmonary embolism, and the number of major/minor bleeding events after discharge. RESULTS: After discharge, 1468 patients were prescribed enoxaparin and 904 dabigatran (1396 total knee arthroplasty and 976 total hip arthroplasty patients). Mean age was 66±10 years, and 60% were female. The cumulative incidence of VTEs during the 12-week follow-up was 0.7%. One patient sustained a VTE during the switch window. Seven patients sustained a pulmonary embolism (0.3%). There was no statistical difference between the total knee arthroplasty and total hip arthroplasty groups. The incidence of major and minor bleeding events during follow-up was 0.3% and 30.3%, respectively. These events had a higher incidence in the dabigatran group compared to the enoxaparin group after discharge (p<0.05), but not between knee and hip replacement groups for major bleeding events. CONCLUSION: A pharmaceutical prophylaxis protocol using LMWH and dabigatran during the post-discharge period resulted in low incidences of VTE and equivalence between treatments. However, the increased number of major and minor bleeding events in patients taking dabigatran is of concern regarding the safety and needs to be evaluated using analyses adjusted for risk factors.

Transfer of skills on LapSim virtual reality laparoscopic simulator into the operating room in urology.

OBJECTIVE: Assessing the predictive validity of the LapSim simulator within a urology residency program. MATERIALS AND METHODS: Twelve urology residents at McGill University were enrolled in the study between June 2008 and December 2011. The residents had weekly training on the LapSim that consisted of 3 tasks (cutting, clip-applying, and lifting and grasping). They underwent monthly assessment of their LapSim performance using total time, tissue damage and path length among other parameters as surrogates for their economy of movement and respect for tissue. The last residents' LapSim performance was compared with their first performance of radical nephrectomy on anesthetized porcine models in their 4(th) year of training. Two independent urologic surgeons rated the resident performance on the porcine models, and kappa test with standardized weight function was used to assess for inter-observer bias. Nonparametric spearman correlation test was used to compare each rater's cumulative score with the cumulative score obtained on the porcine models in order to test the predictive validity of the LapSim simulator. RESULTS: The kappa results demonstrated acceptable agreement between the two observers among all domains of the rating scale of performance except for confidence of movement and efficiency. In addition, poor predictive validity of the LapSim simulator was demonstrated. CONCLUSIONS: Predictive validity was not demonstrated for the LapSim simulator in the context of a urology residency training program.

Determinants of performance on the Transfer Task of the Basic Laparoscopic Urologic Surgery (BLUS(©)) curriculum administered at objective structured clinical examinations.

PURPOSE: To assess determinants of performance on the Transfer Task of the Basic Laparoscopic Urologic Surgery (BLUS(©)) skills curriculum administered at Objective Structured Clinical Examinations (OSCEs). METHODS: After obtaining Institutional Review Board approval and informed consent, urology trainees (Postgraduate Year [PGY]-3 to PGY-5) from four different training programs (A, B, C, D) were recruited for the study. Transfer Task Times (TTTs) were compared and correlated with previous laparoscopic experience, amount of endotrainer practice and scores obtained at practice sessions and other OSCE stations. RESULTS: A total of 37 trainees were evaluated on three successive semiannual OSCEs from May 2011 to May 2012, including 16 (43.2%) trainees from program A with a dedicated laparoscopic skills training program. Compared with trainees from programs B, C, and D, trainees from program A had significantly more practice per week (0 v 45 minutes, p=0.001) and significantly lower median TTTs at OSCEs (114 [68-209] v 74 [52-189] seconds, p=0.001) despite significantly lower number of laparoscopic cases assisted within the previous 6 months (13 [0-57] v 2 [0-35], p=0.001). For program A trainees, TTTs moderately correlated with median TTTs at practice sessions (r=0.57, p=0.001) and negatively correlated with amount of practice per week (r=-0.41, p=0.003). Thus, more training resulted in faster times at OSCEs. On multivariate analysis, amount of practice per week was the only significant predictor of TTTs at OSCEs (p=0.028). CONCLUSION: Performance on the transfer task of BLUS during OSCEs significantly correlated with the amount of practice rather than the number of laparoscopic cases assisted.

Evidence from unilateral lesions of early uncompensable implementation of opposed response-biases in each hemisphere of the brain.

PURPOSE: The intact right hemisphere presents an omissive response-bias and the left hemisphere a commissive response-bias in adults. This research sought to determine whether these hemispherically lateralized response-biases manifest early developmental and uncompensable brain implementation. METHODS: Sixteen teenager and adult participants with focal left hemisphere lesions and fourteen with focal right hemisphere lesions (all with childhood onset: M=13 year recovery period) and 14 normal control participants were recruited. A computerized multitask high order working memory procedure was designed to generate many errors of omission and of commission. RESULTS: The expected double dissociation of response-bias distortion as a function of lesion side was significantly demonstrated on this task and was significantly frontal-lobe dependent. CONCLUSION: The hemispheres of the brain have an opposed response bias that is robustly implemented in infancy through adulthood.