Telemedicine Hip and Knee Arthroplasty Experience During COVID-19.

BACKGROUND: Although telemedicine visits were essential and adopted by providers and patients alike, few studies have been conducted evaluating orthopedic patient perception of the care delivered during these visits. To our knowledge, no study has evaluated specific factors that affected patient satisfaction with telemedicine and the receptiveness to continue virtual visits post COVID-19 in total joint arthroplasty (TJA) patients. Thus, the purposes of our study are to determine the following: (1) patient satisfaction with using TJA telemedicine services, (2) whether patient characteristics might be associated with satisfaction, and (3) whether virtual clinic visits may be used post-COVID-19. METHODS: A prospective, cross-sectional survey study was completed by 126 TJA patients who participated in telemedicine visits with TJA surgeons from May 1, 2020 to August 31, 2020. The survey consisted of questions regarding demographics, satisfaction, and telemedicine experiences. RESULTS: One hundred one (80.2%) patients were satisfied with their telemedicine visit, with patients <80 years old (P = .008) and those with a longer commute time (P = .01) being more satisfied P = .01. There was a significant preference for in-person visits when meeting arthroplasty surgeons for the first time (P < .001), but patients were equally amenable to follow-up telemedicine visits once there was an established relationship with the surgeon. CONCLUSION: Younger patients, patients with longer commute distances, and patients who had established relationships with their provider expressed higher satisfaction with telemedicine arthroplasty visits. Although >80% of patients were satisfied with their telemedicine visit, an established patient-provider relationship may be integral to the success of an arthroplasty telemedicine practice.

Effect of sample thinning on strains and lattice rotations measured from Transmission Kikuchi diffraction in the SEM.

Cross correlation based high angular resolution EBSD (or HR-EBSD) has been developed for measurement of elastic strains, lattice rotations (and estimating GND density). Recent advances in Transmission Kikuchi diffraction (TKD), especially the on-axis geometry allows the possibility of acquiring patterns at higher spatial resolution. However, some controversy remains as to whether stresses/strains measured after the sample thinning process are still representative of the bulk sample. In this paper, we explore a way of applying the HR-EBSD method to study strains and lattice rotations in an initially bulk sample, that is then progressively thinned down until a similar analysis can be performed on thin (and electron transparent) samples. Thus, HR-TKD will be compared as a possible alternative to HR-EBSD, in scenarios when it is not always possible to perform EBSD on the surface of the sample. An estimate of strain relaxation in the sample as a result of sample thinning is presented.

Using local GND density to study SCC initiation.

Strain and geometric necessary dislocations (GNDs) have been mapped with nm-resolution around grain boundaries affected by stress corrosion cracking (SCC) or intergranular oxidation with the aim of clarifying which local conditions that trigger SCC initiation of Alloy 600 in primary water reactor (PWR) water environment. Regions studied included the cracked and uncracked portion of the same SCC-affected grain boundaries and a comparable grain boundary in the as-received condition. High-resolution "on-axis" Transmission Kikuchi Diffraction (TKD) was used to generate strain and GND density based on the cross-correlation image processing method to probe shifts of specific zone axis in the TKD patterns from all regions. All cracked boundaries analyzed had local GND densities higher than 1 × 1016 m-2. Similar grain boundaries, from as-received samples had GNDs of 5 × 1014 m-2, while an intermediate level was found in the oxidized but uncracked portion of the same GB. Results, together with a discussion on the advantages and limitations of the approach, will be presented.

Cognitive skills in preterm infants with bronchopulmonary dysplasia at 1 year adjusted and 2 years chronological age.

Objective: The objective of this study was to evaluate for decline in cognitive scores from 12 to 24 months of age for preterm infants ≤32 weeks gestational age for those with and without bronchopulmonary dysplasia.Study design: In an observational retrospective study, detailed medical data was collected from the electronic medical records of preterm infants born between January 2009 and December 2015 who had cognitive evaluations using Bayley Scales of Infant Development, 3rd ed (BISD-3) at 12 months corrected gestational age and 24 months chronological age. Infants were divided into three groups, bronchopulmonary dysplasia (BPD), prolonged oxygen requirement that did not meet BPD criteria, or pulmonary insufficiency (PI), and respiratory distress only (RDS). Decline in cognitive functions was based on the BISD-3 standard deviation of 15 points, no decline ≤3.5 point, moderate, > 3.5 to <7.5 points, significant >7.5 points.Results: The sample included 165 preterm infants divided into three groups, BPD, n = 39, PI, n = 79, RDS only, n = 47. The groups did not differ on gender, ethnicity, birthweight or gestational age. The groups did not differ in percent of infants who showed no, moderate or significant decline. In all groups, the percentage of infants showing a cognitive decline of >7.5 points varied from 67% to 76%Conclusion: There was no significant difference in cognitive decline for those with and without BPD. Of note is that a large percentage of infants in each group showed at least one-half standard deviation of cognitive decline across the 12 and 24 months evaluations. Our concern is that correcting for gestational age at 12 months may delay early intervention when significant delays are found at 24 months.

Elastic strain tensor measurement using electron backscatter diffraction in the SEM.

The established electron backscatter diffraction (EBSD) technique for obtaining crystallographic information in the SEM has been adapted to permit elastic strain measurement. Basically, the displacement of crystallographic features in an EBSD pattern, such as zone axes, which result from strain in a crystal, is determined by comparing those same features as they appear in a pattern from an unstrained region of the crystal. The comparison is made by cross-correlation of selected regions in the two patterns. Tests show that the sensitivity to displacement measurement is 1 part in 10 000, which translates to a strain sensitivity of 2 parts in 10 000. Eight components of the strain tensor are determined directly and the ninth is calculated using the fact that the free surface of the sample is traction-free. Examples discussed are taken from studies of a lenticular fracture in germanium, the strain distribution surrounding a carbide precipitate in a nickel base alloy and grain boundary studies in another nickel base alloy.

Thyroid hormone insufficiency during brain development reduces parvalbumin immunoreactivity and inhibitory function in the hippocampus.

Thyroid hormones are necessary for brain development. gamma-Amino-butyric acid (GABA)ergic interneurons comprise the bulk of local inhibitory circuitry in brain, many of which contain the calcium binding protein, parvalbumin (PV). A previous report indicated that severe postnatal hypothyroidism reduces PV immunoreactivity (IR) in rat neocortex. We examined PV-IR and GABA-mediated synaptic inhibition in the hippocampus of rats deprived of thyroid hormone from gestational d 6 until weaning on postnatal d 30. Pregnant dams were exposed to propylthiouracil (0, 3, 10 ppm) via the drinking water, which decreased maternal serum T(4) by approximately 50-75% and increased TSH. At weaning, T(4) was reduced by approximately 70% in offspring in the low-dose group and fell below detectable levels in high-dose animals. PV-IR was diminished in the hippocampus and neocortex of offspring killed on postnatal d 21, an effect that could be reversed by postnatal administration of T(4). Dose-dependent decreases in the density of PV-IR neurons were observed in neocortex and hippocampus, with the dentate gyrus showing the most severe reductions (50-75% below control counts). Altered staining persisted to adulthood despite the return of thyroid hormones to control levels. Developmental cross-fostering and adult-onset deprivation studies revealed that early postnatal hormone insufficiency was required for an alteration in PV-IR. Synaptic inhibition of the perforant path-dentate gyrus synapse evaluated in adult offspring, in vivo, revealed dose-dependent reductions in paired pulse depression indicative of a suppression of GABA-mediated inhibition. These data demonstrate that moderate degrees of thyroid hormone insufficiency during the early postnatal period permanently alters interneuron expression of PV and compromises inhibitory function in the hippocampus.

Blind multiridge detection for automatic nondestructive testing using ultrasonic signals.

Ultrasonic imaging has been a significant means for nondestructive testing (NDT). Recently the NDT techniques via the ultrasonic instrumentation have shown the striking capability of the quality control for the material fabrication industry. To the best of our knowledge, all existing signal processing methods require either the a priori information of the ultrasonic signature signals or the manual segmentation operation to achieve the reliable parameters that characterize the corresponding mechanical properties. In this paper, we first provide a general mathematical model for the ultrasonic signals collected by the pulse-echo sensors, then design a totally blind novel signal processing NDT technique relying on neither a priori signal information nor any manual effort. Based on the automatic selection of optimal frame sizes using a proposed new criterion in our scheme, the signature signal can be blindly extracted for further robust multiridge detection. The detected ridge information can be used to estimate the transmission and attenuation coefficients associated with any arbitrary material sample for the fabrication quality control.