Retrieval Analysis of Titanium Nitride Coatings for Orthopaedic Implants.

BACKGROUND: The first generation of titanium nitride (TiN) coatings for orthopaedic implants was clinically introduced in the 1990s because of their promising biocompatibility, wear resistance, and corrosion resistance. This study evaluated the in vivo performance of early TiN-coated knee and hip implants, focusing on the bearing surfaces and mechanisms of in vivo damage. METHODS: There were thirteen TiN-coated implants (5 knee and 8 hip) retrieved from 8 patients as part of a multi-institutional implant retrieval program. The average implantation time was 4.25 years for knees and 17.5 years for hips. Implant revisions occurred for various reasons, including PE wear, loosening, pain, infection, and instability. Components were examined using a semiquantitative scoring method, and surface roughness measurements were performed using white-light interferometry (WLI). Surface morphology, chemistry, and particle characterization were also assessed using scanning electron microscopy. RESULTS: For hips, mild corrosion was found on femoral head tapers, along with severe scratching on certain femoral heads. Knee implants exhibited low burnishing and scratching for both mechanisms. Roughness measurements (Sa) were 37.3 nm (Interquartile Range, IQR = 22.0 to 62.4) for hips and 85.3 nm (IQR = 66.3 to 110) for knees. The observed scratch depth in both hip and knee implants due to 3rd body particles ranged from 0.3 to 1.3 µm. The coating coverage remained intact in the majority of the implants, with two cases of small, localized cohesive chipping and substrate exposure. CONCLUSIONS: The results of this study confirm the potential in vivo durability of early TiN coatings and will be useful in benchmarking wear tests for modern TiN-coated orthopaedic implants.

Publication Rates of Poster and Podium Presentations at the American Association of Hip and Knee Surgeons Annual Meetings 2016 to 2019.

BACKGROUND: The objective of this study was to provide the poster and podium publication rates from the 2016 to 2019 American Association of Hip and Knee Surgeons (AAHKS) annual meetings and assess the quality of presentations ultimately published during this time. METHODS: Posters and podiums from 2016 to 2019 were located through the AAHKS e-poster and meeting archives. Titles were queried on Google, Google Scholar, and PubMed. Presentation title, topic type, number of authors, degrees held by first author, and award status were collected. For each identified full-text publication, journal name, study type, dates of online and print publication, and journal impact factor (JIF) were also obtained. RESULTS: A total of 1,274 abstracts were presented at the 2016 to 2019 AAHKS annual meetings with an overall publication rate of 67.8% (864 of 1,274). Podiums (4.0 months, 95% confidence interval [CI]: 3.0 to 4.0) were more likely to be published earlier than posters (7.0 months, 95% CI: 6.0 to 7.0) (P < .001). The median JIF of published abstracts was 3.3 (95% CI: 3.3 to 3.7) with no significant difference in mean JIF of published posters or podiums (3.3 ± 1.0 versus 3.3 ± 1.0, P = .554). The likelihood of publication was significantly higher for podiums (odds ratio [OR]: 3.41, 95% CI: 2.29 to 5.07, P < .001), award-winning presentations (OR: 4.78, 95% CI: 1.69 to 13.55, P = .003), and with more authors (OR: 1.09, 95% CI: 1.02 to 1.16, P = .014). DISCUSSION: This analysis demonstrates abstracts presented at the AAHKS annual meetings from 2016 to 2019 had an overall publication rate of 67.8%, with podiums (86.4%) 3 times as likely to be published as posters (63.6%). If selected to present at the AAHKS annual meeting, individuals can be confident that their work has a high chance of eventual publication.

Comparison of Early Postoperative Step and Stair Counts With the Direct Anterior Approach Versus the Posterior Approach for Total Hip Arthroplasty.

BACKGROUND: The purpose of this study was to evaluate the impact of direct anterior approach (DAA) or posterior approach (PA) on step and stair counts after total hip arthroplasty using a remotely monitored mobile application with a smartwatch while controlling for baseline characteristics. METHODS: This is a secondary data analysis from a prospective cohort study of patients utilizing a smartphone-based care management platform. The primary outcomes were step and stair counts and changes from baseline through one year. Step and stair counts were available for 1,501 and 847 patients, respectively. Longitudinal regression models were created to control for baseline characteristics. RESULTS: Patients in the DAA group had significantly lower body mass index (P = .049) and comorbidities (P = .028), but there were no significant differences in age (P = .225) or sex (P = .315). The DAA patients had a higher average and improvement from baseline in step count at 2 and 3 weeks postoperatively after controlling for patient characteristics (P = .028 and P = .044, respectively). The average stair counts were higher for DAA patients at one month postoperatively (P = .035), but this difference was not significant after controlling for patient demographics. Average stair ascending speeds and changes from baseline were not different between DAA and PA patients. Descending stair speed was higher at 2 weeks postoperatively for DAA patients, but was no longer higher after controlling for baseline demographics. CONCLUSIONS: After controlling for baseline characteristics, DAA patients demonstrate earlier improvement in step count than PA patients after total hip arthroplasty. However, patient selection and surgeon training may continue to influence outcomes through a surgical approach.

Femoral Head Penetration Rates and Oxidation of Highly Cross-Linked Polyethylene Hip Liners Implanted More Than 10 Years.

BACKGROUND: Highly cross-linked polyethylene (HXLPE) was introduced to improve wear in total hip arthroplasty, with manufacturers implementing different thermal treatments to reduce oxidation. It is important to understand how long-term time in vivo affects the wear of these materials. The purpose of this study was to investigate the wear and oxidative performance of first-generation HXLPE hip inserts implanted for greater than 10 years and compare annealed and remelted HXLPE formulations. METHODS: There were 49 total hip arthroplasty liners retrieved during routine revision surgery as part of an institutional review board-approved implant retrieval program. Penetration rates for the liners were calculated as the difference between the thickness of the unloaded and loaded regions divided by implantation time. Oxidation indices for the rim, locking mechanism, articulating surface, and backside regions were measured using Fourier-transform infrared spectroscopy according to American Society for Testing and Materials 2102. Mann-Whitney U tests were used to determine the statistical difference between annealed and remelted components. RESULTS: The cohort had an average implantation time of 13.1 ± 2.6 years for annealed and 12.1 ± 1.7 years for remelted components. The components were revised most often for polyethylene wear, instability, and loosening. The penetration rate averaged 0.0177 ± 0.014 mm/year for annealed components and 0.015 ± 0.022 mm/year for remelted components. Penetration rates did not differ between the remelted and annealed cohorts (P = .28). Oxidation indices were found to be significantly higher in the annealed cohort for all regions of interest (P < .001). CONCLUSIONS: Oxidation was found to be higher in the annealed HXLPE; however, this does not seem to be associated with greater wear as we found the average penetration rates for the cohorts were low, and the penetration rates were similar between the annealed and remelted cohorts.

Gene expression, evolution, and the genetics of electrosensing in the smalltooth sawfish, Pristis pectinata.

Sawfishes (Pristidae) are large, highly threatened rays named for their tooth-studded rostrum, which is used for prey sensing and capture. Of all five species, the smalltooth sawfish, Pristis pectinata, has experienced the greatest decline in range, currently found in only ~20% of its historic range. To better understand the genetic underpinnings of these taxonomically and morphologically unique animals, we collected transcriptomic data from several tissue types, mapped them to the recently completed reference genome, and contrasted the patterns observed with comparable data from other elasmobranchs. Evidence of positive selection was detected in 79 genes in P. pectinata, several of which are involved in growth factor/receptor tyrosine kinase signaling and body symmetry and may be related to the unique morphology of sawfishes. Changes in these genes may impact cellular responses to environmental conditions such as temperature, dissolved oxygen, and salinity. Data acquired also allow for examination of the molecular components of P. pectinata electrosensory systems, which are highly developed in sawfishes and have likely been influential in their evolutionary success.

The Role of Remote Diagnostics to Better Assess Uroflow Variability: Insights From Combining at Home Uroflows and Frequency Volume Charts From 19,868 Voids Using a Novel, Hand Held, Cellular Embedded Device.

OBJECTIVE: To examine how representative 24-hour data collection is of the overall patient experience utilizing a home uroflow device in men with benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: Home uroflow data were collected with the iO Urology CarePath device from men at a single urology clinic and retrospectively analyzed. Void characteristics were summarized for data collected over 24 hours compared to data collected over several days or weeks with the device (overall study excludes the 24-hour data). A linear mixed-effects model was used to evaluate differences in average Qmax from voids collected during a single 24-hour period compared to the overall study. RESULTS: A total of 486 men (mean age 67.4) used the device resulting in 465 included in the analysis with a total of 15,521 voids in the overall study and 4347 voids in the single-day analysis. Average Qmax from the model was 11.2 mL/s (95% CI: 10.80, 11.65) and 11.2 mL/s (95% CI: 10.81, 11.64) in the 24-hour and overall study groups, respectively. Both groups had similar between (20.3% vs 20.4%) and within-subject (12.0% vs 11.9%) variance. The difference in Qmax was not significantly different (P = .970). A subgroup analysis including voids >150 mL yielded similar results. CONCLUSION: Data show variability in voiding parameters, but similar average Qmax collected in 24 hours as compared to several days/weeks. The combination of home uroflowmetry with frequency-volume chart information can provide objective data and a unique perspective on uroflow variability (UFV) for clinician review to support the development of individualized patient treatment plans.

Evaluating ChatGPT's Capabilities on Orthopedic Training Examinations: An Analysis of New Image Processing Features.

Introduction The efficacy of integrating artificial intelligence (AI) models like ChatGPT into the medical field, specifically orthopedic surgery, has yet to be fully determined. The most recent adaptation of ChatGPT that has yet to be explored is its image analysis capabilities. This study assesses ChatGPT's performance in answering Orthopedic In-Training Examination (OITE) questions, including those that require image analysis. Methods Questions from the 2014, 2015, 2021, and 2022 AAOS OITE were screened for inclusion. All questions without images were entered into ChatGPT 3.5 and 4.0 twice. Questions that necessitated the use of images were only entered into ChatGPT 4.0 twice, as this is the only version of the system that can analyze images. The responses were recorded and compared to AAOS's correct answers, evaluating the AI's accuracy and precision. Results A total of 940 questions were included in the final analysis (457 questions with images and 483 questions without images). ChatGPT 4.0 performed significantly better on questions that did not require image analysis (67.81% vs 47.59%, p<0.001). Discussion While the use of AI in orthopedics is an intriguing possibility, this evaluation demonstrates how, even with the addition of image processing capabilities, ChatGPT still falls short in terms of its accuracy. As AI technology evolves, ongoing research is vital to harness AI's potential effectively, ensuring it complements rather than attempts to replace the nuanced skills of orthopedic surgeons.

Improved patient reported outcomes with the direct anterior approach versus the posterior approach for total hip arthroplasty in the early post-operative period.

BACKGROUND: Patients undergoing total hip arthroplasty (THA) with the direct anterior approach (DAA) may experience faster recovery but may also have better baseline health than those who undergo THA with the posterior approach (PA). This study aimed to compare patient-reported outcome measures (PROMs) between the DAA and PA while controlling for baseline factors. METHODS: This is a secondary data analysis from a prospective cohort study of patients utilizing a smartphone-based care management platform following THA. The primary outcomes were HOOS JR and EQ-5D-5L through 1 year and change from baseline. Longitudinal regression models were created to control for baseline characteristics and investigate the impact of surgical approach on PROMs. RESULTS: Of 1364 THAs evaluated, 731 (53.6%) were female, and 840 (61.6%) used the PA. Patients in the PA group were of similar age but had higher body mass index and comorbidity scores. Pre-operative HOOS JR and EQ-5D-5L were comparable, but higher post-operatively in the DAA group through 6 months (p = 0.03 and p = 0.005). At 1 year post-operatively, HOOS JR and EQ-5D-5L did not vary between groups (p = 0.48 and p = 0.56), nor did changes from baseline (p = 0.47 and p = 0.11). After controlling baseline characteristics, DAA was significantly associated with higher average HOOS JR through 6 months (p = 0.03) and EQ-5D-5L through 3 months (p = 0.005), but not at 12 months (p = 0.89 and p = 0.56). CONCLUSION: THA patients undergoing DAA demonstrate earlier improvements in HOOS JR and EQ-5D-5L. However, these differences may not be clinically significant and are not evident at 1-year post-operative. Patient selection and surgeon training may continue to affect outcomes by surgical approach.

Benthic foraminifera in Gulf of Mexico show temporal and spatial dynamics of microplastics.

Microplastics have accumulated in the environment since plastic production began, with present-day observations that range from marine trenches to mountains. However, research on microplastics has only recently begun so it is unclear how they have changed over time in many oceanic regions. Our study addressed this gap by quantifying the temporal and spatial dynamics of microplastics in two deep-water regions of the Gulf of Mexico (GOM). We isolated agglutinated foraminifera from sediment cores and assessed microplastics that were incorporated into their tests. Our results indicated that microplastics were incorporated by agglutinated foraminifera after plastic production began. Microplastics were higher at deep-water sites and closer to the Mississippi River. This study confirms the presence of microplastic incorporation into agglutinated foraminifera tests and investigates microplastics in deep-water sediments in the GOM. Additional work is needed to fully identify the distribution of microplastics across the GOM and other oceanic basins.

The importance of accounting method and sampling depth to estimate changes in soil carbon stocks.

BACKGROUND: As interest in the voluntary soil carbon market surges, carbon registries have been developing new soil carbon measurement, reporting, and verification (MRV) protocols. These protocols are inconsistent in their approaches to measuring soil organic carbon (SOC). Two areas of concern include the type of SOC stock accounting method (fixed-depth (FD) vs. equivalent soil mass (ESM)) and sampling depth requirement. Despite evidence that fixed-depth measurements can result in error because of changes in soil bulk density and that sampling to 30 cm neglects a significant portion of the soil profile's SOC stock, most MRV protocols do not specify which sampling method to use and only require sampling to 30 cm. Using data from UC Davis's Century Experiment ("Century") and UW Madison's Wisconsin Integrated Cropping Systems Trial (WICST), we quantify differences in SOC stock changes estimated by FD and ESM over 20 years, investigate how sampling at-depth (> 30 cm) affects SOC stock change estimates, and estimate how crediting outcomes taking an empirical sampling-only crediting approach differ when stocks are calculated using ESM or FD at different depths. RESULTS: We find that FD and ESM estimates of stock change can differ by over 100 percent and that, as expected, much of this difference is associated with changes in bulk density in surface soils (e.g., r = 0.90 for Century maize treatments). This led to substantial differences in crediting outcomes between ESM and FD-based stocks, although many treatments did not receive credits due to declines in SOC stocks over time. While increased variability of soils at depth makes it challenging to accurately quantify stocks across the profile, sampling to 60 cm can capture changes in bulk density, potential SOC redistribution, and a larger proportion of the overall SOC stock. CONCLUSIONS: ESM accounting and sampling to 60 cm (using multiple depth increments) should be considered best practice when quantifying change in SOC stocks in annual, row crop agroecosystems. For carbon markets, the cost of achieving an accurate estimate of SOC stocks that reflect management impacts on soils at-depth should be reflected in the price of carbon credits.

Complications of GreenLight Laser vs Transurethral Resection of the Prostate for Treatment of Lower Urinary Tract Symptoms: Meta-analysis of Randomized Trials.

OBJECTIVE: To compare perioperative outcomes and complications between GreenLight and transurethral resection of the prostate (TURP) for benign prostatic hyperplasia. METHODS: A systematic review and random effects meta-analysis of randomized trials comparing GreenLight with TURP was completed. Primary outcomes included periprocedural milestones, 12 predefined complications, Clavien-Dindo class III-V complications, reoperations (all-cause), and a composite of reoperations and readmissions. Metaregression assessed the relationship between patient- and study-level factors with periprocedural outcomes and reoperation rates. RESULTS: The review included 13 randomized trials with 1757 patients (839 GreenLight; 918 TURP). Procedure time was 10 minutes (95% CI: 5 to 15; P < .001) longer with GreenLight, while catheterization time (mean difference=-1.3days; 95% CI: -1.7 to -0.9; P<.001) and hospital stay (mean difference=-2.1days; 95% CI: -2.5 to -1.7; P<.001) were shorter. Bleeding-related complications, including clot retention (risk ratio [RR]=0.12; 95% CI: 0.05 to 0.32; P<.001) and transfusion (RR=0.26; 95% CI: 0.12 to 0.58; P = .001), as well as sexual dysfunction (RR=0.66; 95% CI: 0.45 to 0.98; P = .04), were less frequent with GreenLight. All other complications occurred at similar frequencies between groups. The risks of reoperation (RR: 1.17; 95% CI: 0.82 to 1.66; P = .38) and reoperation or readmission (RR: 1.05; 95% CI: 0.76 to 1.44; P = .79) did not differ. CONCLUSION: GreenLight achieved shorter catheterization times and hospital stays with lower rates of sexual dysfunction and bleeding-related complications compared to TURP.

Are Corrosion and Material Loss a Threat for Titanium-Titanium Tapers in Total Hip Arthroplasty Modular Acetabular Components?

BACKGROUND: Extensive research has reported on fretting corrosion and material loss for a variety of metal taper interfaces in orthopedic devices. For modular acetabular shell-liner constructs, the interfaces studied thus far have consisted of mixed-metal pairings, and the risk of fretting corrosion and material loss for the all-titanium (Ti) shell-liner taper junction in one ceramic-on-ceramic (COC) design remains poorly understood. We asked: do Ti shell-liner taper interfaces in COC total hip arthroplasty devices show in vivo evidence of (1) fretting and/or corrosion, and (2) quantifiable potential material loss? METHODS: We examined 22 shell-liner pairs and 22 single liners from retrieved COC components. The taper interface surfaces were assessed for fretting corrosion using a semiquantitative scoring method and imaged with scanning electron microscopy. A subcohort of components was measured with a coordinate measuring machine, and volumetric material loss and maximum wear depth were calculated. RESULTS: Fretting corrosion at the taper interfaces was minimal to mild for 95% of liners and 100% of shells. Imaging revealed fretting marks within a band of corrosion on some implants and evidence of corrosion not in the proximity of mechanical damage. Estimated material loss ranged from 0.2 to 1.3 mm3 for liners, and 0.5 to 1.1 mm3 for shells. Maximum wear depth for all components was 0.03 mm or less. CONCLUSIONS: Our results indicate that, compared to other taper junctions in total joint arthroplasty, the risk of corrosion and material loss may be minimal for Ti shell-liner interfaces.

Analyzing the Quality and Readability of Online Hyaluronic Acid Knee Injection Resources.

INTRODUCTION: We analyzed the quality of information about Hyaluronic acid (HA) knee injections for osteoarthritis using DISCERN, a tool that grades the quality of websites. We also analyzed readability with Flesch-Kincaid grade reading levels (FKGRL). METHODS: Lists of the top ten included sites from Google searches about HA injections were evaluated using DISCERN to determine their quality. Additional variables collected were site category, Health on Net (HON) certification, search result rank, and FKGRL. DISCERN scores were compared and grouped by these variables. RESULTS: Most sites were measured as fair in quality. Greater DISCERN scores were produced from searches using general terminology, sites with HON labels, and academic journal publications. CONCLUSION: This study indicates information quality for HA injections online is fair. The data also indicates that patients can best educate themselves using HON labels, general search terms, and information from academic journals when possible.

Robotic-Assisted Total Knee Arthroplasty Has Similar Rates of Prosthetic Noise Generation as Conventional Total Knee Arthroplasty.

Background: Noise has been reported to occur with relatively high frequency after conventional total knee arthroplasty (C-TKA), and this may impact the incidence of patient satisfaction and function. The purpose of this study was to compare the rate of patient-reported prosthetic noise generation after robotically-assisted TKA (RA-TKA) and C-TKA. Methods: A retrospective study was conducted of unilateral primary RA-TKAs and C-TKAs performed between 2018 and 2021. Patients completed a survey consisting of 4 Likert scale questions related to prosthetic noise generation and Knee Injury and Osteoarthritis Score Joint Replacement and Forgotten Joint Score were assessed prospectively preoperatively and at a minimum of 1-year of clinical follow-up. Statistical analysis was done utilizing T-tests and chi-square tests, with statistical significance defined as a P-value < .05. Results: One hundred sixty-two RA-TKAs and 320 C-TKAs with similar baseline characteristics and functions were included. There were no significant differences in hearing or feeling grinding, popping, clicking, or clunking (40.7% vs 38.1%; P = .647) between groups. Most RA-TKAs and C-TKAs were not dissatisfied regarding noise generation (70.4% vs 73.1%; P = .596). In both cohorts, patients who reported noise generation had lower average Forgotten Joint Scores (45.5 vs 66.1; P < .001) and lower postoperative Knee Injury and Osteoarthritis Score Joint Replacement scores (72.0 vs 81.4; P < .001) than those who did not experience noise generation. Conclusions: While RA-TKA may facilitate soft tissue balancing, there were no differences in prosthetic noise generation between RA-TKA and C-TKA. However, those who experience implant-generated noise have lower functional outcome scores.

Autonomous robotics is driving Perseverance rover's progress on Mars.

NASA's Perseverance rover uses robotic autonomy to achieve its mission goals on Mars. Its self-driving autonomous navigation system (AutoNav) has been used to evaluate 88% of the 17.7-kilometer distance traveled during its first Mars year of operation. Previously, the maximum total autonomous distance evaluated was 2.4 kilometers by the Opportunity rover during its 14-year lifetime. AutoNav has set multiple planetary rover records, including the greatest distance driven without human review (699.9 meters) and the greatest single-day drive distance (347.7 meters). The Autonomous Exploration for Gathering Increased Science (AEGIS) system analyzes wide-angle imagery onboard to autonomously select targets for observations by the SuperCam instrument, a multimode sensor suite capable of millimeter-scale geochemical and mineralogical analysis. AEGIS enables observations of scientifically interesting targets during or immediately after long drives without the need for ground communication. OnBoard Planner (OBP) is a scheduling capability planned for operational use in September 2023 that has the potential to reduce energy usage by up to 20% and complete drive and arm-contact science campaigns in 25% fewer days on Mars. This paper presents an overview of the AutoNav, AEGIS, and OBP capabilities used on Perseverance.