Monitoring indirect impact of COVID-19 pandemic on services for cardiovascular diseases in the UK.

OBJECTIVE: To monitor hospital activity for presentation, diagnosis and treatment of cardiovascular diseases during the COVID-19) pandemic to inform on indirect effects. METHODS: Retrospective serial cross-sectional study in nine UK hospitals using hospital activity data from 28 October 2019 (pre-COVID-19) to 10 May 2020 (pre-easing of lockdown) and for the same weeks during 2018-2019. We analysed aggregate data for selected cardiovascular diseases before and during the epidemic. We produced an online visualisation tool to enable near real-time monitoring of trends. RESULTS: Across nine hospitals, total admissions and emergency department (ED) attendances decreased after lockdown (23 March 2020) by 57.9% (57.1%-58.6%) and 52.9% (52.2%-53.5%), respectively, compared with the previous year. Activity for cardiac, cerebrovascular and other vascular conditions started to decline 1-2 weeks before lockdown and fell by 31%-88% after lockdown, with the greatest reductions observed for coronary artery bypass grafts, carotid endarterectomy, aortic aneurysm repair and peripheral arterial disease procedures. Compared with before the first UK COVID-19 (31 January 2020), activity declined across diseases and specialties between the first case and lockdown (total ED attendances relative reduction (RR) 0.94, 0.93-0.95; total hospital admissions RR 0.96, 0.95-0.97) and after lockdown (attendances RR 0.63, 0.62-0.64; admissions RR 0.59, 0.57-0.60). There was limited recovery towards usual levels of some activities from mid-April 2020. CONCLUSIONS: Substantial reductions in total and cardiovascular activities are likely to contribute to a major burden of indirect effects of the pandemic, suggesting they should be monitored and mitigated urgently.

In Vitro Kinematic Assessment of a Hinged Elbow Orthosis Following Lateral Collateral Ligament Injury.

PURPOSE: Elbow lateral collateral ligament injuries (LCLI) are often managed with protected mobilization using a hinged elbow orthosis (HEO). The objective of this investigation was to determine the effectiveness of an HEO in stabilizing the elbow following LCLI. METHODS: Seven fresh-frozen cadaveric upper extremity specimens were studied using a custom simulator that enabled elbow motion via computer-controlled actuators and servomotors attached to relevant tendons. Specimens were examined in 4 arm positions (dependent, overhead, horizontal, and varus) and 2 forearm positions (pronation and supination) during both passive and simulated active elbow extension. Specimens were examined before and after simulated LCLI, and then with the addition of an HEO. The lateral collateral ligament, common extensor origin, and lateral elbow capsule were sectioned in the injury model. An electromagnetic tracking system measured ulnohumeral kinematics. RESULTS: The orthosis did not change elbow stability in any arm position during active motion. Muscle activation and forearm pronation enhanced stability in the dependent, horizontal, and varus positions while the HEO was applied. CONCLUSIONS: This HEO does not improve the in vitro stability of the elbow following simulated LCLI. CLINICAL RELEVANCE: An HEO may be safe to use during active motion, but when a patient is not activating the muscles normally (ie, owing to fatigue or cognitive impairment) and the arm is in positions in which the weight of the orthosis might increase joint distraction, an HEO may be harmful. If an HEO is used, the forearm should be braced in pronation following LCLI.

Osseous Anatomy of the Distal Radioulnar Joint: An Assessment Using 3-Dimensional Modeling and Clinical Implications.

PURPOSE: Using a novel technique, we assess and describe the distal radioulnar joint (DRUJ) anatomy. The purpose of this study was to provide the anatomic dimensions of the DRUJ and to evaluate contralateral symmetry. METHODS: Computed tomography images of 100 cadaveric forearms were obtained. Three-dimensional models of the radius and ulna were generated and evaluated using 3-dimensional modeling software. Measurements of the radius of curvature of the sigmoid notch (SN) and ulnar head (UH), as well as the length of the SN and volar and dorsal lips were performed in the axial and coronal sequences. In addition, mid-coronal angular measurements were made of the SN and UH to quantify the obliquity of the DRUJ. All coronal measurements were performed with the forearm set to neutral rotation. RESULTS: The average ulnar variance was -0.9 ± 1.8 mm. The radius of curvature of the UH (8.2 ± 1.3 mm) was markedly smaller than that of the SN (18.2 ± 8.5 mm). The length of the SN in coronal sequences increased from volar to dorsal by 65%. The mid-coronal angle (DRUJ obliquity) of the SN and UH measured 6.0 ± 9.9° and 18.0 ± 9.9°, respectively. A direct inverse correlation was demonstrated in the obliquity of the DRUJ and ulnar variance. All anatomic measurements were similar when comparing bilateral specimens. CONCLUSIONS: The SN length tends to increase in size from volar to dorsal. Bilateral specimens from the same individual demonstrate similarities and can be cautiously used for comparison. CLINICAL RELEVANCE: The relationships and measurements demonstrated in this study can be a guide when considering reconstructive procedures or dealing with complex fractures involving the DRUJ.

A biomechanical assessment of fixation methods for a coronoid prosthesis.

BACKGROUND: The coronoid process is an integral component for maintaining elbow joint stability. When fixation of a fracture is not possible, prosthetic replacement may be a feasible solution for restoring stability. The purpose of this in-vitro biomechanical study was to compare fixation methods for a coronoid implant. METHODS: A coronoid prosthesis was subjected to distally-directed tip loading after implantation using four fixation methods: press-fit, anterior-to-posterior screws, posterior-to-anterior screws, and cement. Testing was performed on seven fresh-frozen ulnae in a repeated-measures model. Rounds of cyclic loading were applied at 1 Hz, for 100 cycles, increased in 50 N increments up to a maximum of 400 N. Micro-motion of the implant was quantified using an optical-tracking system. Outcome variables included total displacement, distal translation, gapping, anterior translation and axial stem rotation. FINDINGS: Cement fixation reduced implant micro-motion compared to screw fixation, while the greatest implant micro-motion was observed in press-fit fixation. Comparing screw-fixation techniques, posterior-anterior screws provided superior stability only in distal translation. The implant did not experience displacements exceeding 0.9 mm with screw or cement fixation. INTERPRETATION: Cement fixation provides the best initial fixation for a coronoid implant. However, the stability provided by both methods of screw fixation may be sufficient to allow osseous integration to be achieved for long-term fixation. Large displacements were observed using the press-fit fixation technique, suggesting that modifications would need to be developed and tested before this technique could be recommended for clinical application.

Accuracy assessment of 3D bone reconstructions using CT: an intro comparison.

Computed tomography provides high contrast imaging of the joint anatomy and is used routinely to reconstruct 3D models of the osseous and cartilage geometry (CT arthrography) for use in the design of orthopedic implants, for computer assisted surgeries and computational dynamic and structural analysis. The objective of this study was to assess the accuracy of bone and cartilage surface model reconstructions by comparing reconstructed geometries with bone digitizations obtained using an optical tracking system. Bone surface digitizations obtained in this study determined the ground truth measure for the underlying geometry. We evaluated the use of a commercially available reconstruction technique using clinical CT scanning protocols using the elbow joint as an example of a surface with complex geometry. To assess the accuracies of the reconstructed models (8 fresh frozen cadaveric specimens) against the ground truth bony digitization-as defined by this study-proximity mapping was used to calculate residual error. The overall mean error was less than 0.4 mm in the cortical region and 0.3 mm in the subchondral region of the bone. Similarly creating 3D cartilage surface models from CT scans using air contrast had a mean error of less than 0.3 mm. Results from this study indicate that clinical CT scanning protocols and commonly used and commercially available reconstruction algorithms can create models which accurately represent the true geometry.

In vitro assessment of the contact mechanics of reverse-engineered distal humeral hemiarthroplasty prostheses.

BACKGROUND: Distal humeral hemiarthroplasty alters cartilage contact mechanics, which may predispose to osteoarthritis. Current prostheses do not replicate the native anatomy, and therefore contribute to these changes. We hypothesized that prostheses reverse-engineered from the native bone shape would provide similar contact patterns as the native articulation. METHODS: Reverse-engineered hemiarthroplasty prostheses were manufactured for five cadaveric elbows based on CT images of the distal humerus. Passive flexion trials with constant muscle forces were performed with the native articulation intact while bone motions were recorded using a motion tracking system. Motion trials were then repeated after the distal humerus was replaced with a corresponding reverse-engineered prosthesis. Contact areas and patterns were reconstructed using computer models created from CT scan images combined with the motion tracker data. The total contact areas, as well as the contact area within smaller sub-regions of the ulna and radius, were analyzed for changes resulting from hemiarthroplasty using repeated-measures ANOVAs. FINDINGS: Contact area at the ulna and radius decreased on average 42% (SD 19%, P=.008) and 41% (SD 42%, P=.096), respectively. Contact area decreases were not uniform throughout the different sub-regions, suggesting that contact patterns were also altered. INTERPRETATION: Reverse-engineered prostheses did not reproduce the same contact pattern as the native joints, possibly because the thickness of the distal humerus cartilage layer was neglected when generating the prosthesis shapes or as a consequence of the increased stiffness of the metallic implants. Alternative design strategies and materials for hemiarthroplasty should be considered in future work.

Selecting the diameter of a radial head implant: an assessment of local landmarks.

INTRODUCTION: Little information exists on radial head implant diameter sizing methods. When the native head is absent due to extensive comminution or previous excision, the lesser sigmoid notch may be a useful landmark for sizing. We evaluated the reliability of native radial head measurements, and the lesser sigmoid notch, as landmarks for radial head implant diameter sizing. METHODS: We examined 27 fresh frozen ulnae and their corresponding radial heads. The maximum, minimum, and dish diameters of the radial heads were measured. A radial head implant diameter was selected based on the congruency of the trial implants with the radius of curvature of the lesser sigmoid notch. Intraobserver and interobserver reliability for all measurements and implant selection were assessed using intraclass correlation coefficients (ICC). Correlations between the native radial head measurements and the selected radial head implant diameter or the lesser sigmoid notch radius of curvature were assessed using the Pearson correlation coefficient (PCC). RESULTS: Radial head diameter measurements demonstrated strong to excellent intraobserver (ICC ≥ 0.75) and interobserver reliability (ICC ≥ 0.82). The lesser sigmoid notch sizing method showed poor interobserver reliability (ICC = 0.34). Only a moderate correlation was found between the native radial head and the lesser sigmoid notch (PCC ≤ 0.80) or the selected radial head implant size (PCC ≤ 0.59). CONCLUSION: Radial head diameter measurements showed excellent reliability, suggesting that the excised radial head, when available, should be used to select the implant diameter. The reliability of using the lesser sigmoid notch for sizing the diameter of radial head implants was only moderate, suggesting this is an unreliable landmark for implant diameter sizing.

Phospholipids in rice: significance in grain quality and health benefits: a review.

Phospholipids (PLs) are a major class of lipid in rice grain. Although PLs are only a minor nutrient compared to starch and protein, they may have both nutritional and functional significance. We have systemically reviewed the literature on the class, distribution and variation of PLs in rice, their relation to rice end-use quality and human health, as well as available methods for analytical profiling. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and their lyso forms are the major PLs in rice. The deterioration of PC in rice bran during storage was considered as a trigger for the degradation of rice lipids with associated rancid flavour in paddy and brown rice. The lyso forms in rice endosperm represent the major starch lipid, and may form inclusion complexes with amylose, affecting the physicochemical properties and digestibility of starch, and hence its cooking and eating quality. Dietary PLs have a positive impact on several human diseases and reduce the side-effects of some drugs. As rice has long been consumed as a staple food in many Asian countries, rice PLs may have significant health benefits for those populations. Rice PLs may be influenced both by genetic (G) and environmental (E) factors, and resolving G×E interactions may allow future exploitation of PL composition and content, thus boosting rice eating quality and health benefits for consumers. We have identified and summarised the different methods used for rice PL analysis, and discussed the consequences of variation in reported PL values due to inconsistencies between methods. This review enhances the understanding of the nature and importance of PLs in rice and outlines potential approaches for manipulating PLs to improve the quality of rice grain and other cereals.

Accuracy assessment of an imaging technique to examine ulnohumeral joint congruency during elbow flexion.

A CT-based imaging technique to investigate ulnohumeral joint congruency of elbows undergoing physiologic flexion is introduced. This technique, which employed landmark registration and a previously developed inter-bone distance algorithm, was validated experimentally. Results obtained with this imaging technique were validated in a single specimen by comparing the resulting joint congruency maps to results obtained with experimental casting in a static position. Additionally, the accuracy of the registration technique was assessed in four specimens using fiducial and target registration error to evaluate the positional and angular accuracy. Preliminary data from an intact cadaveric elbow was shown to demonstrate the utility of this technique. The overall accuracy of the registration was better than 1 mm, and the congruency maps showed excellent correspondence with the casting, validating the use of a CT-based imaging technique to examine the congruency of joints undergoing quasi-static flexion.

Functional outcome of arthroscopic extensor carpi radialis brevis tendon release in chronic lateral epicondylitis.

PURPOSE: To evaluate outcomes of arthroscopic tennis elbow release in a population of patients with chronic, recalcitrant symptoms, a large number of workers' compensation claims, and high occupational demands using standardized outcome measures, including a detailed objective assessment of workplace demands. METHODS: We treated 36 patients with chronic lateral epicondylitis with an arthroscopic release. A standardized protocol was used to measure strength, motion, and outcomes (American Shoulder and Elbow Surgeons Elbow [ASES-e] score, Short Form-12, Patient-Rated Tennis Elbow evaluation [PRTEE], and Work Limitations Questionnaire-26). RESULTS: The mean duration of symptoms before surgery was 30 months. A total of 25 of 36 patients were employed in heavy or repetitive occupations and 23 of 36 were involved in a workers' compensation claim. The final overall results were favorable, with 30 of 36 subjects reporting improvement with surgery. The final mean Mayo Elbow Performance Index score was 78.6 +/- 16.5 (22 = good to excellent, 9 = fair, and 5 = poor). The average total PRTEE was 26.2 +/- 24.3 out of 100. The average ASES-e pain score was 16.1 +/- 15.0 and the average ASES-e function score was 27.9 +/- 8.8. Patients in heavy or repetitive occupations and those with workers' compensation claims had significantly worse outcome scores (Mayo Elbow Performance Index, ASES, and PRTEE). Based on Work Limitations Questionnaire-26 scores, patients with workers' compensation claims had significantly greater difficulties with physical (36.8 vs 3.2, p < .001), output (40.8 vs 3.1, p = .002), mental (36.0 vs 9.0, p = .05), and social (27.7 vs 6.3, p = .05) workplace demands. CONCLUSIONS: Arthroscopic tennis elbow release provides symptomatic improvement in most patients with lateral epicondylitis. Patient selection and reported occupational demands have an important role in determining outcomes. More work is required to identify factors predicting outcome in this difficult subgroup.

Assessment of screw displacement axis accuracy and repeatability for joint kinematic description using an electromagnetic tracking device.

Screw displacement axes (SDAs) have been employed to describe joint kinematics in biomechanical studies. Previous reports have investigated the accuracy of SDAs combining various motion analysis techniques and smoothing procedures. To our knowledge, no study has assessed SDA accuracy describing the relative movement between adjacent bodies with an electromagnetic tracking system. This is important, since in relative motion, neither body is fixed and consequently sensitivity to potential measurement errors from both bodies may be significant. Therefore, this study assessed the accuracy of SDAs for describing relative motion between two moving bodies. We analyzed numerical simulated data, and physical experimental data recorded using a precision jig and electromagnetic tracking device. The numerical simulations demonstrated SDA position accuracy (p=0.04) was superior for single compared to relative body motion, whereas orientation accuracy (p=0.2) was similar. Experimental data showed data-filtering (Butterworth filter) improved SDA position and orientation accuracies for rotation magnitudes smaller or equal to 5.0 degrees, with no effect at larger rotation magnitudes (p<0.05). This suggests that in absence of a filter, SDAs should only be calculated at rotations of greater than 5.0 degrees. For rotation magnitudes of 0.5 degrees (5.0 degrees ) about the SDA, SDA position and orientation error measurements determined from filtered experimental data were 3.75+/-0.30 mm (3.31+/-0.21 mm), and 1.10+/-0.04 degrees (1.04+/-0.03 degrees ), respectively. Experimental accuracy values describing the translation along and rotation about the SDA, were 0.06+/-0.00 mm and 0.09+/-0.01 degrees, respectively. These small errors establish the capability of SDAs to detect small translations, and rotations. In conclusion, application of SDAs should be a useful tool for describing relative motion in joint kinematic studies.