Increased actual sling wear is associated with better early patient-reported and image-based outcomes after shoulder surgery.

BACKGROUND: Prior studies have failed to show differences in functional outcomes for patient-reported sling use after rotator cuff repair. Temperature-sensing devices are used to more accurately measure brace adherence. The purposes of this study were to quantify actual sling adherence and its predictors and to establish whether increased sling adherence is associated with improved functional and image-based outcomes. METHODS: We performed a prospective cohort study of 65 patients undergoing shoulder surgery requiring ≥4 weeks of postoperative sling use. Temperature-sensing devices were implanted in the slings to monitor sling adherence. Patient-reported sling adherence was determined from a questionnaire. Patients were considered 80% adherent if they wore the sling 16 h/d (112 h/week) when 20 h/d was prescribed. The primary outcomes were patient-reported and actual sling adherence, patient-reported outcomes (American Shoulder and Elbow Surgeons score and visual analog scale pain score) within 12 months postoperatively, and image-based failure based on ultrasound or radiography at 6 weeks and 1 year postoperatively. RESULTS: Patient-reported sling adherence was highly sensitive (82.8%), was poorly specific (28.6%), had low accuracy (53.1%), and was weakly correlated with actual sling adherence (r = 0.32, P = .009). On multivariable logistic regression analysis, male patients were 91% less likely than female patients to be adherent with sling use (odds ratio, 0.09; 95% confidence interval [CI], 0.02-0.42; P = .002). Additionally, obese and morbidly obese patients were 88% (95% CI, 0.02-0.84; P = .033) and 98% (95% CI, 0.002-0.27; P = .003), respectively, less likely than non-obese patients to adhere to sling wear postoperatively. After we controlled for surgical procedure, visual analog scale pain scores were significantly better at 6 weeks (ß = -1.47; 95% CI, -2.88 to -0.05; P = .04) and 3 months (ß = -1.68; 95% CI, -3.28 to -0.08; P = .04) if patients adhered to sling wear. A receiver operating characteristic curve showed that 13.6 hours and 15.4 hours of daily sling wear optimized image-based outcomes at 6 weeks (failure rate, 0% vs. 16%; P = .01) and 1 year (failure rate, 3% vs. 28%; P = .008) postoperatively, respectively. CONCLUSION: The results of this study demonstrate that patient-reported sling adherence is unreliable, adherence can be predicted by female sex and lower body mass index, and increased sling adherence is associated with improved early pain scores and image-based outcomes. These data can help inform future studies using postoperative sling protocols as patient-reported sling adherence is not an accurate method to assess sling use.

The Effect of Patients' Understanding of Sling Necessity and Home Assistance on Sling Wear After Shoulder Surgery.

BACKGROUND: Perioperative education and socioeconomic factors influence patient behavior. Recent evidence has suggested that sling compliance is associated with improved outcomes after shoulder surgery; it is important to investigate factors that influence sling compliance. PURPOSE: To determine the associations between postoperative sling wear and patients' understanding of sling necessity, postoperative home assistance, and social deprivation. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A total of 66 patients were prospectively enrolled from 2018 to 2020 if they were ≥18 years of age and undergoing shoulder surgery requiring a sling for at least 1 month postoperatively. Sling wear was measured using a temperature-sensing device. At 6 weeks postoperatively, patients' understanding for sling necessity was determined by their response to a question on the Medical Adherence Measure questionnaire, "Why did you have to wear a shoulder sling?" The Patient Understanding Grading Scale (PUGS) was developed to quantify patient responses. PUGS was graded 1 to 3, with grade 1 corresponding to the least technical knowledge. Patient characteristics, social deprivation (Area Deprivation Index [ADI]), and home assistance were additionally analyzed. RESULTS: There were no significant differences in baseline characteristics between patients when stratified by PUGS grade. Multivariable linear regression analysis for total hours of sling wear per week showed that patients with PUGS grade 2 (ß, 48.2 hours; P = .007) and grade 3 (ß, 59.5 hours; P = .003) wore their slings significantly more than grade 1 patients. Patients with home assistance had significantly greater day hours (73.5 ± 33.0 vs 44.0 ± 24.5 hours; P = .037) of sling wear per week, but there was no difference in night sling hours. Patients older than 60 years wore their slings significantly more, while men and those with a higher body mass index (BMI) wore their slings significantly less. ADI was not significantly associated with sling wear. CONCLUSION: This study demonstrates that patients with greater understanding for sling necessity, those with home assistance, and patients >60 years have greater sling wear, while male patients and those with a higher BMI have lower sling compliance. ADI was not a significant contributor.

Topological Singularity Induced Chiral Kohn Anomaly in a Weyl Semimetal.

The electron-phonon interaction (EPI) is instrumental in a wide variety of phenomena in solid-state physics, such as electrical resistivity in metals, carrier mobility, optical transition, and polaron effects in semiconductors, lifetime of hot carriers, transition temperature in BCS superconductors, and even spin relaxation in diamond nitrogen-vacancy centers for quantum information processing. However, due to the weak EPI strength, most phenomena have focused on electronic properties rather than on phonon properties. One prominent exception is the Kohn anomaly, where phonon softening can emerge when the phonon wave vector nests the Fermi surface of metals. Here we report a new class of Kohn anomaly in a topological Weyl semimetal (WSM), predicted by field-theoretical calculations, and experimentally observed through inelastic x-ray and neutron scattering on WSM tantalum phosphide. Compared to the conventional Kohn anomaly, the Fermi surface in a WSM exhibits multiple topological singularities of Weyl nodes, leading to a distinct nesting condition with chiral selection, a power-law divergence, and non-negligible dynamical effects. Our work brings the concept of the Kohn anomaly into WSMs and sheds light on elucidating the EPI mechanism in emergent topological materials.

Learning about Black Hole Binaries from their Ringdown Spectra.

The coalescence of two black holes generates gravitational waves that carry detailed information about the properties of those black holes and their binary configuration. The final coalescence cycles are in the form of a ringdown: a superposition of quasinormal modes of the merged remnant black hole. Each mode has an oscillation frequency and decay time that in general relativity is determined by the remnant's mass and spin. Measuring the frequency and decay time of multiple modes makes it possible to measure the remnant's mass and spin, and to test the waves against the predictions of gravity theories. In this Letter, we show that the relative amplitudes of these modes encode information about a binary's geometry. Focusing on the large mass-ratio limit, which provides a simple-to-use tool for effectively exploring parameter space, we demonstrate how a binary's geometry is encoded in the relative amplitudes of these modes, and how to parametrize the modes in this limit. Although more work is needed to assess how well this carries over to less extreme mass ratios, our results indicate that measuring multiple ringdown modes from coalescence may aid in measuring important source properties, such as the misalignment of its members' spins and orbit.