Exploring the Performance of an Artificial Intelligence-Based Load Sensor for Total Knee Replacements.

Using tibial sensors in total knee replacements (TKRs) can enhance patient outcomes and reduce early revision surgeries, benefitting hospitals, the National Health Services (NHS), stakeholders, biomedical companies, surgeons, and patients. Having a sensor that is accurate, precise (over the whole surface), and includes a wide range of loads is important to the success of joint force tracking. This research aims to investigate the accuracy of a novel intraoperative load sensor for use in TKRs. This research used a self-developed load sensor and artificial intelligence (AI). The sensor is compatible with Zimmer's Persona Knee System and adaptable to other knee systems. Accuracy and precision were assessed, comparing medial/lateral compartments inside/outside the sensing area and below/within the training load range. Five points were tested on both sides (medial and lateral), inside and outside of the sensing region, and with a range of loads. The average accuracy of the sensor was 83.41% and 84.63% for the load and location predictions, respectively. The highest accuracy, 99.20%, was recorded from inside the sensing area within the training load values, suggesting that expanding the training load range could enhance overall accuracy. The main outcomes were that (1) the load and location predictions were similar in accuracy and precision (p > 0.05) in both compartments, (2) the accuracy and precision of both predictions inside versus outside of the triangular sensing area were comparable (p > 0.05), and (3) there was a significant difference in the accuracy of load and location predictions (p < 0.05) when the load applied was below the training loading range. The intraoperative load sensor demonstrated good accuracy and precision over the whole surface and over a wide range of load values. Minor improvements to the software could greatly improve the results of the sensor. Having a reliable and robust sensor could greatly improve advancements in all joint surgeries.

Decoding medical school narrative evaluations: Is natural language processing an antidote to the leniency bias?

Observational assessments in the clinical context are a cornerstone of evaluation in medical education. Leniency bias, described in performance management in the business arena appears to widely impact these assessments with medical training. Natural language processing provides a potential tool that medical educators may leverage to decipher underlying meaning in narrative assessment. A "proof-of-concept" study at the Cumming School of Medicine supports this notion and suggests further work would be a worthwhile pursuit in this field.

A clinically useful and biologically informative genomic classifier for papillary thyroid cancer.

Clinical management of papillary thyroid cancer depends on estimations of prognosis. Standard care, which relies on prognostication based on clinicopathologic features, is inaccurate. We applied a machine learning algorithm (HighLifeR) to 502 cases annotated by The Cancer Genome Atlas Project to derive an accurate molecular prognostic classifier. Unsupervised analysis of the 82 genes that were most closely associated with recurrence after surgery enabled the identification of three unique molecular subtypes. One subtype had a high recurrence rate, an immunosuppressed microenvironment, and enrichment of the EZH2-HOTAIR pathway. Two other unique molecular subtypes with a lower rate of recurrence were identified, including one subtype with a paucity of BRAFV600E mutations and a high rate of RAS mutations. The genomic risk classifier, in addition to tumor size and lymph node status, enabled effective prognostication that outperformed the American Thyroid Association clinical risk stratification. The genomic classifier we derived can potentially be applied preoperatively to direct clinical decision-making. Distinct biological features of molecular subtypes also have implications regarding sensitivity to radioactive iodine, EZH2 inhibitors, and immune checkpoint inhibitors.

Mitigating diagnostic performance bias in a skin-tone balanced dermatology curriculum.

INTRODUCTION: Individuals with skin of colour (SoC) have delayed diagnosis and poorer outcomes when presenting with some dermatologic conditions when compared to individuals with light skin (LS). The objective of this study was to determine if diagnostic performance bias can be mitigated by a skin-tone balanced dermatology curriculum. METHODOLOGY: A prospective randomised intervention study occurred over 2 weeks in 2020 at a Canadian medical school. A convenience sample of all first-year medical students (n = 167) was chosen. In week 1, all participants had access to dermatology podcasts and were randomly allocated to receive non-analytic training (NAT; online patient 'cards') on either SoC cases or LS cases. In week 2, all participants received combined training (CT; NAT and analytic training through workshops on how to apply dermatology diagnostic rules for all skin tones). Participating students completed two formative assessments after weeks 1 and 2. RESULTS: Ninety-two students participated in the study. After week 1, both groups had a lower diagnostic performance on SoC (p = 0.0002 and p = 0.002 for students who trained on LS 'cards' and SoC 'cards', respectively). There was a significant decrease in mean skin tone difference in both groups after week 2 (initial training on SoC: 5.8% (SD 12.2) pre, -1.4% (14.7) post, p = 0.007; initial training on LS: 7.8% (15.4) pre, -4.0% (11.8%) post, p = 0.0001). Five students participated in a post-study survey in 2023, and all found the curriculum enhanced their diagnostic skills in SoC. CONCLUSIONS: SoC performance biases of medical students disappeared after CT in a skin tone-balanced dermatology curriculum.

How much is enough? Proposing achievement thresholds for core EPAs of graduating medical students in Canada.

PURPOSE: The transition towards Competency-Based Medical Education at the Cumming School of Medicine was accelerated by the reduced clinical time caused by the COVID-19 pandemic. The purpose of this study was to define a standard protocol for setting Entrustable Professional Activity (EPA) achievement thresholds and examine their feasibility within the clinical clerkship. METHODS: Achievement thresholds for each of the 12 AFMC EPAs for graduating Canadian medical students were set by using sequential rounds of revision by three consecutive groups of stakeholders and evaluation experts. Structured communication was guided by a modified Delphi technique. The feasibility/consequence models of these EPAs were then assessed by tracking their completion by the graduating class of 2021. RESULTS: The threshold-setting process resulted in set EPA achievement levels ranging from 1 to 8 across the 12 AFMC EPAs. Estimates were stable after the first round for 9 of 12 EPAs. 96.27% of EPAs were successfully completed by clerkship students despite the shortened clinical period. Feasibility was predicted by the slowing rate of EPA accumulation overtime during the clerkship. CONCLUSION: The process described led to consensus on EPA achievement thresholds. Successful completion of the assigned thresholds was feasible within the shortened clerkship.[Box: see text].

Posterior cruciate-retaining total knee arthroplasty exhibits small kinematic changes in the first postoperative year.

PURPOSE: Fluoroscopic knee kinematics have historically been quantified at least 1 year after total knee arthroplasty (TKA). The purpose of this study was to longitudinally assess knee kinematics at 6-12 weeks, 6 months, and 1 year after TKA to determine if earlier evaluation may be justified. METHODS: Twenty-one patients participated after undergoing TKA with a posterior cruciate ligament-retaining fixed-bearing prosthesis. Fluoroscopic examinations of lunge, kneel, and step-up activities were performed at 12 ± 4 weeks (V1), 7 ± 2 months (V2), and 13 ± 2 months (V3) postoperatively. Images were analyzed using a three-dimensional to two-dimensional image registration technique. Maximum flexion poses for lunging and kneeling were compared between visits with repeated-measures statistical tests. For the step-up activity, mixed-effects linear models were constructed for condylar anteroposterior (AP) contact points and tibial internal rotation throughout flexion. Estimated marginal means of fitted values were plotted with 95% confidence intervals and used to compare mean kinematics between visits. RESULTS: There were no significant changes in maximum lunging flexion over time (p = 0.405), though significant increases in maximum kneeling flexion were observed between V1 (106 ± 8°) and V2 (110 ± 9°) (p = 0.006), and V1 and V3 (113 ± 9°) (p = 0.0003). While statistical differences were calculated for lunging medial condyle AP translation and kneeling tibial internal rotation, absolute differences in condylar AP contact locations were less than ~ 2 mm between all visits during both movements. For the step-up activity, tibial internal rotation increased with flexion, and there were pair-wise significant differences at all flexion angles between V1-V2 (p < 0.001) and V1-V3 (p < 0.001). Anterior medial condylar translation was observed with flexion, with pair-wise significant differences present for V1-V3 (p = 0.005) and V2-V3 (p < 0.001). The lateral condyle exhibited initial posterior translation followed by anterior translation with increasing flexion, with pair-wise differences between all visits (p < 0.005 for all comparisons). CONCLUSION: Though statistical differences were observed between visits for all activities, variations in estimated mean condylar positions were within ~ 2 mm from ~ 12 weeks to 1 year. Considering measurement error averages approximately 1 mm for sagittal plane translations, these results indicate that knee kinematics during kneel, lunge, and step-up activities may be sustained from as early as 12 weeks after TKA.

Perception versus reality: A case-matched study assessing the intraoperative hemodynamics of minimally invasive retroperitoneal versus transperitoneal approach to pheochromocytomas.

BACKGROUND: Pheochromocytomas produce excess catecholamines that can result in intraoperative hemodynamic instability. Centers have reported variations in intraoperative hemodynamics with the retroperitoneoscopic versus the laparoscopic transperitoneal approach to adrenalectomies. When the retroperitoneoscopic approach was initiated for pheochromocytomas at our institution, the perception was of improved intraoperative hemodynamics, hypothesizing that increased retroperitoneoscopic insufflation pressures caused decreased venous return and less fluctuation in circulating catecholamines. The purpose of this study was to examine if a difference in intraoperative hemodynamics exists between a size-matched cohort of laparoscopic transperitoneal and retroperitoneoscopic pheochromocytoma patients. METHODS: Unilateral adrenalectomies for pheochromocytoma performed via laparoscopic transperitoneal or retroperitoneoscopic approaches from 2015 to 2021 were identified from a surgical database. As larger tumors often underwent a laparoscopic transperitoneal approach, cases were matched 1:1 by tumor size. All patients received phenoxybenzamine. Groups were compared by patient characteristics, preoperative blockade, intraoperative hemodynamics and management, and early postoperative outcomes. RESULTS: There were 13 laparoscopic transperitoneal adrenalectomy cases matched to 13 retroperitoneoscopic cases according to tumor size. Both groups (laparoscopic transperitoneal and retroperitoneoscopic) were similar for age (53 years), body mass index (28.5 vs 29.7), sex (69% female), and side (8 vs 7 right). There was no difference in preoperative 24-hour urine metanephrines/normetanephrines (9.9/8.0 vs 2.4/5.7 µmol/day). The phenoxybenzamine dose was similar in both groups (112 vs 114 mg/24 hours), as were baseline heart rate, blood pressure, and mean arterial pressure. There was no difference in any intraoperative hemodynamic parameters or vasoactive interventions. Operative time, length of stay, and 30-day emergency visits were similar between groups. CONCLUSION: This matched cohort study did not find a difference in intraoperative hemodynamics between laparoscopic transperitoneal and retroperitoneoscopic adrenalectomy approaches for pheochromocytoma in appropriately selected and blocked patients.

Cost-effectiveness analysis of molecular testing for cytologically indeterminate thyroid nodules.

BACKGROUND: Thyroid nodules affect up to 65% of the population. Although fine needle aspirate (FNA) cytology is the gold standard for diagnosis, 15-30% of results are indeterminate. Molecular testing may aid in the diagnosis of nodules and potentially reduce unnecessary surgery. However, these tests are associated with significant costs. The objective of this study was to evaluate the cost-effectiveness of Afirma, a commercially available molecular test, in cytologically indeterminate thyroid nodules. METHODS: The base case was a solitary thyroid nodule with no additional high-risk features and an indeterminate FNA. Decision tree analysis was performed from the single payer perspective with a 1-year time horizon. Costing data were collected through micro-costing methodology. A probabilistic sensitivity analysis was performed. The primary outcome was the incremental cost effectiveness ratio (ICER) of cost per thyroid surgery avoided. RESULTS: Over 1 year, mean cost estimates were $8176.28 with 0.58 effectiveness for the molecular testing strategy and $6016.83 with 0.07 effectiveness for current standard management. The ICER was $4234.22 per surgery avoided. At a willingness-to-pay (WTP) threshold of $5000 per surgery avoided, molecular testing is cost-effective with 63% certainty. CONCLUSION: This cost-effectiveness analysis suggests utilizing Afirma for indeterminate solitary thyroid nodules is a cost-effective strategy for avoiding unnecessary thyroid surgery. With a $5000 WTP threshold, molecular testing has a 63% chance of being the more cost-effective strategy. The cost effectiveness varies based on the cost of the molecular test and the value of Afirma for patients with indeterminate thyroid nodules depends on the WTP threshold to avoid unnecessary thyroid surgery.

The Prospective Implementation of the 2015 ATA Guidelines and Modified ATA Recurrence Risk Stratification System for Treatment of Differentiated Thyroid Cancer in a Canadian Tertiary Care Referral Setting.

Objective: To present clinical outcomes of the prospective implementation of the 2015 American Thyroid Association (ATA) guidelines for the management of thyroid nodules and differentiated thyroid cancer (DTC) using the modified ATA recurrence risk (RR) stratification system. Methods: We prospectively analyzed 612 patients with DTC treated between April 2017 and December 2021 in Calgary, Alberta. Each patient was prospectively assigned a modified ATA RR and American Joint Committee Cancer 8th edition stage. Initial risk stratification and consideration of the 2015 ATA guidelines guided surgical management as well as the indication for and dose of radioiodine (RAI) and other adjuvant therapies. Patients were assessed for their response to treatment (RTT) at 2-years postoperatively. Results: There were 479 patients who had 2-year follow-up data and were included in the study. Of these patients, there were 253 (53%) low-, 129 (27%) intermediate-, and 97 (20%) high-RR patients. Of these, 227 patients (47%) underwent total thyroidectomy (TTX) plus RAI, 178 (37%) underwent TTX only, and 74 (16%) underwent lobectomy. The RTT at 2 years was excellent for 89% (66) of patients with lobectomy, 84% (149) for TTX only, and 53% (121) for TTX plus RAI. Among 253 patients who were deemed low RR, 85% (216) had excellent RTT, 13% (32) indeterminate RTT, 2% (4) biochemical incomplete RTT, and 1 patient had structural incomplete RTT. The intermediate RR group had the following RTT outcomes: 64% (83) excellent, 23% (30) indeterminate, 6% (7) biochemical incomplete, and 7% (9) structural incomplete. The high RR group had the worst RTT outcomes, with 38% (37) excellent, 19% (18) indeterminate, 10% (10) biochemical incomplete, and 33% (32) structural incomplete RTT. Conclusions: The 2015 ATA RR stratification system is useful for predicting disease status at 2-year post-treatment in patients with DTC. The 2015 ATA guidelines and modified ATA RR stratification treatment recommendations may reduce thyroid cancer overtreatment by including lobectomy as a definitive treatment option for low-risk thyroid cancers and selective use of RAI for intermediate and high-risk patients.

Early outcomes using a 'kinematic retaining' total knee replacement - A multicentre prospective study at two years follow-up.

BACKGROUND: Although predictable implant longevity in total knee replacement (TKR) is now established, work continues to satisfy the demands of patients who seek full restoration of the painless function of the native knee following TKR. This prospective study examines the early clinical outcomes of 156 patients implanted with a novel 'kinematic-retaining' (KR) implant. METHODS: 156 Physica KR TKRs were implanted for primary osteoarthritis at three European centres. Patients were reviewed up to two years using radiographic, clinical and functional evaluations. RESULTS: Of the 137 patients retained at two years' follow up, none had been revised. Within 6 post-operative months, 51.7% and 79.9% had excellent clinical and functional KSS values respectively, increasing to 81.8% and 88.3% beyond two years. Mean KSS improvement was 34.8 (from 48.6 to 83.4). All KOOS sub-scores improved significantly with total KOOS improving from a mean of 35.5 (SD ±13.0) to 86.5 (±13.7) at two years post-operatively. Pain and sports KOOS sub-scores improved rapidly during the early post-operative periods, with sustained improvements beyond this. Mean OKS improved by 44.1 (±5.1) at two years. VAS satisfaction scores improved significantly at all time points beyond six weeks. Mean FJS-12 was 75.7 at two years, with no significant effects of age or gender. No progressive adverse radiographic features were noted. CONCLUSIONS: Early clinical and radiographic outcomes of this kinematic-retaining knee prosthesis are promising, with improvements in clinical parameters similar to, or exceeding those published in other contemporary TKR designs. LEVEL OF EVIDENCE: II, Multicentre Prospective cohort study.

Performance of Confirmatory Tests for Diagnosing Primary Aldosteronism: a Systematic Review and Meta-Analysis.

BACKGROUND: Confirmatory tests are recommended for diagnosing primary aldosteronism, but the supporting evidence is unclear. METHODS: We searched Medline, EMBASE, and the Cochrane Central Register of Controlled Trials. Studies evaluating any guideline-recommended confirmatory test (ie, saline infusion test, salt loading test, fludrocortisone suppression test, and captopril challenge test), compared with a reference standard were included. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the risk of bias. Meta-analyses were conducted using hierarchical summary receiver operating characteristic models. RESULTS: Fifty-five studies were included, comprising 26 studies (3654 participants) for the recumbent saline infusion test, 4 studies (633 participants) for the seated saline infusion test, 2 studies (99 participants) for the salt loading test, 7 studies (386 participants) for the fludrocortisone suppression test, and 25 studies (2585 participants) for the captopril challenge test. Risk of bias was high, affecting more than half of studies, and across all domains. Studies with case-control sampling overestimated accuracy by 7-fold (relative diagnostic odds ratio, 7.26 [95% CI, 2.46-21.43]) and partial verification or use of inconsistent reference standards overestimated accuracy by 5-fold (5.12 [95% CI, 1.48-17.77]). There were large variations in how confirmatory tests were conducted, interpreted, and verified. Under most scenarios, confirmatory testing resulted in an excess of missed cases. The certainty of evidence underlying each test (Grading of Recommendations, Assessment, Development, and Evaluations) was very low. CONCLUSIONS: Recommendations for confirmatory testing in patients with abnormal screening tests and high probability features of primary aldosteronism are based on very low-quality evidence and their routine use should be reconsidered.

Platelet-Rich Plasma Augmentation of Arthroscopic Rotator Cuff Repair Lowers Retear Rates and Improves Short-Term Postoperative Functional Outcome Scores: A Systematic Review of Meta-Analyses.

Purpose: The purpose of this study is to conduct a systematic review of meta-analyses of rotator cuff repair using platelet-rich plasma (PRP) to identify whether PRP improves clinical function and rate of tendon retears. We will (1) conduct a systematic review of the current meta-analyses of rotator cuff repair using platelet-rich plasma available in the literature, (2) evaluate the quality of these meta-analyses using the Preferred Reporting Items for Systematic Review (PRISMA) methodology, (3) identify whether PRP improves clinical function and rate of tendon retears, and develop guidance to improve future studies in this area. Methods: We carried out a systematic review of previous meta-analyses published on the clinical outcomes of PRP used in the treatment of rotator cuff tears. We performed a comprehensive search of PubMed, Medline, Cochrane, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Embase databases, using various combinations of the commercial names of each PRP preparation and "rotator cuff" (with its associated terms), looking specifically at human meta-analysis studies involving the repair of the rotator cuff tendon surgically in the English language. Data validity was assessed and collected on clinical outcomes. Following this, a meta-analysis was undertaken. Results: Thirteen meta-analyses met the inclusion and exclusion criteria. All were considered of similar quality with Oxman-Guyatt index of 9 and PRISMA score of more than 24. A total of 1,800 patients with an average follow up of 12 to 36 months. The use of PRP for arthroscopic rotator cuff tear, when compared with controls, leads to a lower number of retears, improved short-term postoperative scores, and functional outcome. The following postoperative scores were reported: Constant: 12, Simple Shoulder Test: 10, ASES (American Shoulder and Elbow Surgeons): 9, UCLA (University of California, Los Angeles) 11, SANE (Single Assessment Numeric Evaluation) 1, VAS (visual analog scale): 6, and Retears: 13. Subgroup analysis showed that leukocyte content and gel application make no difference in the effectiveness of PRP. VAS score subgroup analysis showed short-term pain relief. Conclusions: Our study shows that PRP is effective in reducing retears after rotator cuff repair and improving functional outcome scores and reducing short-term pain. Level of Evidence: Level III, systematic review of Level I-III studies.

The adoption of the endoscopic retroperitoneal approach to the adrenal gland - Conversion factors and learning points.

INTRODUCTION: Minimally invasive adrenalectomy includes laparoscopic transperitoneal (LA) and retroperitoneoscopic (RP) approaches. This study reviewed the local adrenalectomy practice to identify characteristics and outcomes between patients undergoing adrenalectomy via LA, RP, and RP requiring conversion (RPC). METHODS: Adrenalectomies documented in a prospective surgical database were reviewed. Demographics, diagnosis, surgical approach/conversion, body mass index (BMI), radiographic body measurements (RBM), tumor size, operative time (OT), length of stay (LOS), and 30-day post-operative emergency (ED) visits were collected. RESULTS: 203 adrenalectomies were reviewed from 2015 to 2020. The RP group had the shortest OT (124 ± 54 min, p = 0.281 vs LA, p < 0.001 vs RPC) and LOS (1.6 ± 1.0 days, p < 0.001 vs LA and RPC). There was an 18% conversion rate from RP to LA, and in one case to laparotomy. The RPC group had greater BMI, OT, LOS, and ED visits than LA and RP. The RPC group had less favorable RBM (p < 0.001). On multivariate analysis, RBM impacted OT, LOS, and ED visits (p < 0.05). DISCUSSION: The RP approach had shorter OT and LOS. BMI and RBM may increase risk of conversion, OT, LOS, and ED visits. Preoperative RBM may aid in appropriate patient selection for a RP approach.

External Validation of Clinical Prediction Models in Unilateral Primary Aldosteronism.

BACKGROUND: Targeted treatment of primary aldosteronism (PA) is informed by adrenal vein sampling (AVS), which remains limited to specialized centers. Clinical prediction models have been developed to help select patients who would most likely benefit from AVS. Our aim was to assess the performance of these models for PA subtyping. METHODS: This external validation study evaluated consecutive patients referred for PA who underwent AVS at a tertiary care referral center in Alberta, Canada during 2006-2018. In alignment with the original study designs and intended uses of the clinical prediction models, the primary outcome was the presence of lateralization on AVS. Model discrimination was evaluated using the C-statistic. Model calibration was assessed by comparing the observed vs. predicted probability of lateralization in the external validation cohort. RESULTS: The validation cohort included 342 PA patients who underwent AVS (mean age, 52.1 years [SD, 11.5]; 201 [58.8%] male; 186 [54.4%] with lateralization). Six published models were assessed. All models demonstrated low-to-moderate discrimination in the validation set (C-statistics; range, 0.60-0.72), representing a marked decrease compared with the derivation sets (range, 0.80-0.87). Comparison of observed and predicted probabilities of unilateral PA revealed significant miscalibration. Calibration-in-the-large for every model was >0 (range, 0.35-1.67), signifying systematic underprediction of lateralizing disease. Calibration slopes were consistently <1 (range, 0.35-0.87), indicating poor performance at the extremes of risk. CONCLUSIONS: Overall, clinical prediction models did not accurately predict AVS lateralization in this large cohort. These models cannot be reliably used to inform the decision to pursue AVS for most patients.

Apparent failed and discordant adrenal vein sampling: A potential confounding role of cortisol cosecretion?

OBJECTIVE: Adrenal vein sampling (AVS) and computed tomography (CT) often show confusingly discordant lateralisation results in primary aldosteronism (PA). We tested a biochemical algorithm using AVS data to detect cortisol cosecretion as a potential explanation for discordant cases. DESIGN: Retrospective analysis from a large PA + AVS database. PATIENTS: All patients with PA and AVS, 2005-2020. MEASUREMENTS: An algorithm using biochemical data from paired AVS + CT images was devised from physiological first principles and informed by data from unilateral, AVS-CT concordant patients. The algorithm involved calculations based upon the expectation that low cortisol levels exist in adrenal vein effluent opposite an aldosterone-and-cortisol-producing adrenal mass and may reverse lateralisation due to inflated aldosterone/cortisol ratios. MAIN OUTCOMES: The algorithm was applied to cases with discordant CT-AVS lateralisation to determine whether this might be a common or explanatory finding. Clinical and biochemical characteristics of identified cases were collected via chart review and compared to CT-AVS concordant cases to detect evidence of biological plausibility for cortisol cosecretion. RESULTS: From a total of 588 AVS cases, 141 AVS + CT pairs were clear unilateral PA cases, used to develop the three-step algorithm for AVS interpretation. Applied to 88 AVS + CT discordant pairs, the algorithm suggested possible cortisol cosecretion in 40%. Case review showed that the proposed cortisol cosecretors, as identified by the algorithm, had low/suppressed adrenocorticotropic hormone levels, larger average nodule size and lower plasma aldosterone. CONCLUSIONS: Pending external validation and outcome verification by surgery and tissue immunohistochemistry, cortisol cosecretion from aldosteronomas may be a common explanation for discordant CT-AVS results in PA.

The outcomes of surgical management of failed two-stage revision knee arthroplasty.

Background Joint infection following total knee arthroplasty has significant consequences on both the patient and healthcare system. Two stage revision arthroplasties is viewed as the gold standard in management. However, recurrence of infection following this procedure is a growing clinical problem for a multitude of reasons. Despite a variety of surgical options for management of failure of two-stage revision arthroplasty, the potential for complications and functional limitation remains high, and the optimal strategy is yet to be determined. Methods We performed a systematic review of all papers reporting on the outcomes of the surgical management of failure of two-stage revision arthroplasty published up to and including January 2020. Data was extracted on patient demographics, study design, methodological quality, indication for surgery, surgical technique, clinical and functional outcomes, and complications. Results Nine papers with a total of 273 patients were found and analysed All surgical techniques had mixed results in term of clinical and functional outcomes, and the rate of complications was high in all studies. Knee arthrodesis had the lower risk of failure than repeat 2 stage revision. Poor patient immunological status and limb status were weakly associated with increased risk of failure. Conclusion Despite failure of two-stage revision arthroplasty being a growing clinical issue, we were not able to identify any consistently superior surgical technique for the management of this scenario. Knee arthrodesis appears to provide the best results for improving quality of life and reducing infection recurrence, although the complication rate is high and the functional outcomes appear to be worse. Further larger and prospective studies are needed to elucidate optimal surgical management in different patient subsets.

Properly Collected Plasma Metanephrines Excludes PPGL After False-Positive Screening Tests.

CONTEXT: False-positive results are common for pheochromocytoma/paraganglioma (PPGL) real-world screening. OBJECTIVE: Determine the correlation between screening urine and seated plasma metanephrines in outpatients where PPGL was absent, compared to meticulously prepared and supine-collected plasma metanephrines with age-adjusted references. DESIGN: Retrospective cohort study. SETTING: Databases from a single-provider provincial laboratory (2012-2018), a validated PPGL registry, and a manual chart review from a specialized endocrine testing unit. PATIENTS: PPGL registry data excluded known PPGL cases from the laboratory database. Outpatients having both urine and plasma metanephrines <90 days apart. METHODS: The correlation between urine and seated plasma measures along with the total positivity rate. All cases of plasma metanephrines drawn in the endocrine unit were reviewed for test indication and test positivity rate. RESULTS: There were 810 non-PPGL pairs of urine and plasma metanephrines in the laboratory database; 46.1% of urine metanephrines were reported high. Of seated outpatient plasma metanephrines drawn a median of 5.9 days later, 19.2% were also high (r = 0.33 and 0.50 for normetanephrine and metanephrine, respectively). In contrast, the meticulously prepared and supine collected patients (n = 139, 51% prior high urine metanephrines) had <3% rate of abnormal high results in patients without known PPGL/adrenal mass. CONCLUSIONS: There was a poor-to-moderate correlation between urine and seated plasma metanephrines. Up to 20% of those with high urine measures also had high seated plasma metanephrines in the absence of PPGL. Properly prepared and collected supine plasma metanephrines had a false-positive rate of <3% in the absence of known PPGL/adrenal mass.

Outcomes of a Specialized Clinic on Rates of Investigation and Treatment of Primary Aldosteronism.

Importance: Primary aldosteronism (PA) is one of the most common causes of secondary hypertension but remains largely unrecognized and untreated. Objective: To understand the outcomes of a specialized clinic on rates of evaluation and treatment of PA in the context of secondary factors. Design, Setting, and Participants: This population-based cohort study was conducted in Alberta, Canada, using linked administrative data between April 1, 2012, and July 31, 2019, on adults identified as having hypertension. Main Outcomes and Measures: We evaluated each step of the diagnostic and care pathway for PA to determine the proportion of people with hypertension who received screening, subtyping, and targeted treatment for PA. Variations in diagnosis and treatment were examined according to individual-level, clinician-level, and system-level characteristics. Results: Of the 1.1 million adults with hypertension, 7941 people (0.7%) were screened for PA. Among those who were screened, 1703 (21.4%) had positive test results consistent with possible PA, and 1005 (59.0%) of these were further investigated to distinguish between unilateral and bilateral forms of PA. Only 731 individuals (42.9%) with a positive screen result received disease-targeted treatment. Geographic zones and clinician specialty were the strongest determinants of screening, subtyping, and treatment of PA, with the highest rates corresponding to the location of the provincial endocrine hypertension program. Conclusions and Relevance: In this cohort, less than 1% of patients expected to have PA were ever formally diagnosed and treated. These findings suggest that a system-level approach to assist with investigation and treatment of PA may be highly effective in closing care gaps and improving clinical outcomes.

Surgical Outcomes Among Primary Aldosteronism Patients Without Visible Adrenal Lesions.

CONTEXT: Many patients with unilateral primary aldosteronism (PA) have normal adrenal imaging, but little is known about their outcome following adrenalectomy. OBJECTIVE: To evaluate biochemical and clinical outcomes after adrenalectomy in patients with unilateral PA and normal-appearing adrenal imaging. DESIGN: Retrospective cohort study of patients seen between January 2006 and May 2018. SETTING: A Canadian tertiary care PA referral center. PATIENTS: Consecutive individuals with PA, normal cross-sectional adrenal imaging, and lateralizing adrenal vein sampling (AVS) who underwent adrenalectomy during the study period. PRIMARY OUTCOME: Biochemical response to adrenalectomy graded according to the Primary Aldosteronism Surgical Outcome criteria. RESULTS: A total of 40 patients were included. Biochemical outcomes were available for 33 people (mean age, 54.7 years; 91% male; median follow-up, 2.7 months), with 28 (85%) showing a complete or partial response and 5 (15%) with no response. Clinical outcomes were available for 36 people (mean age, 54.6 years; 86% male; median follow-up, 9.8 months), with 31 (86%) demonstrating a complete or partial response and 5 (14%) with no response. CONCLUSIONS: The prognosis after adrenalectomy is highly favorable for patients with unilateral PA and normal-appearing adrenal imaging. Patients with lateralizing disease should be considered for surgery despite apparently normal adrenal imaging.