Impressive Short-Term Improvement in Functional Outcome and Quality of Life after Primary Total Hip Arthroplasty (THA) in the Orthogeriatric Patient in a Prospective Monocentric Trial.

Background/Objectives: Osteoarthritis (OA) represents the most frequent chronic joint disease worldwide. Facing an aging population, resulting from the demographic change, the number of primary total hip arthroplasties (THA) will further increase. Although the geriatric patient strongly differs from the younger one, the current literature on elective orthopedic surgery in the geriatric patient is scarce. This work analyses, whether geriatric patients receiving primary THA significantly improve in terms of their (1) mobility and functional outcome and (2) health-related quality of life at four to six weeks as well as three months postoperatively. Methods: In a prospective study design, we analyzed 101 geriatric patients with osteoarthritis of the hip receiving primary THA. The study is part of the ongoing "Special Orthopaedic Geriatrics" (SOG) trial, which is funded by the German Federal Joint Committee (GBA). In addition to a preoperative comprehensive geriatric assessment (CGA), the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the EQ5D-5L were imposed preoperatively (t0), at four to six weeks (t1), and at three months (t2) postoperatively. Results: The 101 enrolled patients had a mean age of 78.1 ± 4.9 years. The total WOMAC score and almost all subcategories significantly improved at four to six weeks as well as three months postoperatively in comparison to the preoperative results (p < 0.001). The same was observed for the EQ-5D-5L, showing significant improvement in overall health at both time points (p < 0.001) and all subcategories (p < 0.05). Conclusions: This study implies that a geriatric patient benefits as much from elective primary THA as a younger patient. However, the preoperative comprehensive geriatric assessment with screening for risk factors is of utmost importance. Regarding the aging population, a lot of effort is needed to obtain more knowledge about geriatric patients receiving elective orthopedic surgery.

[Risk and complication profiles of orthogeriatric patients in elective hip and knee joint replacement]. / Risiko- und Komplikationsprofil orthogeriatrischer Patienten bei elektivem Hüft- und Kniegelenkersatz.

BACKGROUND: The care of geriatric patients undergoing elective orthopedic surgery is becoming increasingly more important due to demographic trends. Compared to geriatric traumatology, however, there are still no established orthogeriatric care models in Germany and therefore hardly any scientific data. The aim of this study was to describe the risk and complication profiles in older patients with elective hip and knee replacements. METHODS: In a prospective study data were collected from orthogeriatric patients with indications for elective hip and knee replacement surgery who fulfilled defined inclusion and exclusion criteria between January 2021 and August 2023 in the orthopedic department of a German university hospital for the descriptive analysis of risk and complication profiles. In addition to a preoperative and perioperative data analysis, a follow-up was conducted 4-6 weeks and 3 months postoperatively. RESULTS: The surgical risk profile of the patient population analyzed was characterized by advanced age (78.4 ± 4.8 years), preobesity/obesity (76%), multimorbidity (7.4 ± 3.1 comorbidities), polypharmacy (7.5 ± 3.8 medications), immobility (short physical performance battery 7.1 ± 2.6), prefrailty/frailty (87%), frequent anticoagulation (22%) and a high number of potentially inappropriate medications (64%). Complication events mainly occurred within the first 7 days postoperatively and 90% of the events within this recording period were minor complications. The overall complication rate significantly decreased in the follow-up period. CONCLUSION: Due to the high risk and complication profiles the routine use of orthogeriatric co-management models for elective orthopedic surgery should be considered in the future.

Acute compartment syndrome of the thigh after total knee arthroplasty: a case report.

INTRODUCTION: Acute compartment syndrome of the thigh after total knee arthroplasty is a rarely described complication. After the assessment of the diagnosis, immediate surgical intervention is necessary to prevent further tissue damage. Since only a few cases have been described and because of the high complication rate, early detection is essential for ensuring patient outcomes. CASE PRESENTATION: After total knee arthroplasty in a high-volume university hospital, a 57-year-old Caucasian female patient experienced strong, disproportional pain in the ventromedial thigh of the affected leg, which did not respond to an adequate adjustment in pain medication. Imaging revealed a distinct swelling of the vastus intermedius muscle. This resulted in acute compartment syndrome of the thigh, which was immediately surgically treated. Apart from receiving surgery distal from the affected compartment and continuous intake of acetylsalicylic acid, the patient had no risk factors for developing compartment syndrome. The patient's recovery was uneventful, with timely wound closure and discharge to outpatient care without significant functional limitations. CONCLUSION: Acute compartment syndrome of the thigh represents a rare, but severe complication that can occur after orthopedic surgery. In our case, no triggering factors for the development of acute compartment syndrome, such as the use of a tourniquet, were detected. Even in unusual locations, compartment syndrome should be considered as a differential diagnosis. With sufficient evidence, immediate fasciotomy should be indicated.

Homo sapiens reached the higher latitudes of Europe by 45,000 years ago.

The Middle to Upper Palaeolithic transition in Europe is associated with the regional disappearance of Neanderthals and the spread of Homo sapiens. Late Neanderthals persisted in western Europe several millennia after the occurrence of H. sapiens in eastern Europe1. Local hybridization between the two groups occurred2, but not on all occasions3. Archaeological evidence also indicates the presence of several technocomplexes during this transition, complicating our understanding and the association of behavioural adaptations with specific hominin groups4. One such technocomplex for which the makers are unknown is the Lincombian-Ranisian-Jerzmanowician (LRJ), which has been described in northwestern and central Europe5-8. Here we present the morphological and proteomic taxonomic identification, mitochondrial DNA analysis and direct radiocarbon dating of human remains directly associated with an LRJ assemblage at the site Ilsenhöhle in Ranis (Germany). These human remains are among the earliest directly dated Upper Palaeolithic H. sapiens remains in Eurasia. We show that early H. sapiens associated with the LRJ were present in central and northwestern Europe long before the extinction of late Neanderthals in southwestern Europe. Our results strengthen the notion of a patchwork of distinct human populations and technocomplexes present in Europe during this transitional period.

The ecology, subsistence and diet of ~45,000-year-old Homo sapiens at Ilsenhöhle in Ranis, Germany.

Recent excavations at Ranis (Germany) identified an early dispersal of Homo sapiens into the higher latitudes of Europe by 45,000 years ago. Here we integrate results from zooarchaeology, palaeoproteomics, sediment DNA and stable isotopes to characterize the ecology, subsistence and diet of these early H. sapiens. We assessed all bone remains (n = 1,754) from the 2016-2022 excavations through morphology (n = 1,218) or palaeoproteomics (zooarchaeology by mass spectrometry (n = 536) and species by proteome investigation (n = 212)). Dominant taxa include reindeer, cave bear, woolly rhinoceros and horse, indicating cold climatic conditions. Numerous carnivore modifications, alongside sparse cut-marked and burnt bones, illustrate a predominant use of the site by hibernating cave bears and denning hyaenas, coupled with a fluctuating human presence. Faunal diversity and high carnivore input were further supported by ancient mammalian DNA recovered from 26 sediment samples. Bulk collagen carbon and nitrogen stable isotope data from 52 animal and 10 human remains confirm a cold steppe/tundra setting and indicate a homogenous human diet based on large terrestrial mammals. This lower-density archaeological signature matches other Lincombian-Ranisian-Jerzmanowician sites and is best explained by expedient visits of short duration by small, mobile groups of pioneer H. sapiens.

[Fast-Track-Arthroplasty]. / Fast-Track-Endoprothetik.

INTRODUCTION: Essential components of fast-track or enhanced recovery programs in arthroplasty are the optimization of interdisciplinary organizational processes, as well as pre-, intra- and postoperative procedures in everyday clinical practice. The early postoperative mobilization of patients after joint replacement surgery is of central importance, with the aim of avoiding pain and complications. This article provides a detailed overview of fast-track procedures that have already been established in many units. Furthermore, it demonstrates the clinical advantages of FastTrack for total hip arthroplasty (THA) in an evidence-based manner within the framework of a randomized study design. MATERIAL AND METHODS: 194 primary THA patients were examined after randomization into two single-blinded groups; Fast-Track (n = 98) or conventional treatment path (n = 96). Mobilization was defined as the primary outcome parameter, measured in seconds using the Timed Up and Go Test (TUG). Secondary parameters were the achievable walking distance in meters and pain using the numerical rating scale (NRS). All parameters were recorded preoperatively and daily until the sixth postoperative day. RESULTS: No complications or revisions were recorded within the first postoperative week. The fast-track group showed significantly better TUG values and walking distance results compared to the conventional group until the sixth postoperative day (p < 0.05, respectively). There was no significant difference regarding the pain assessment (NRS) (p > 0.05). CONCLUSION: The use of Fast-Track in hip arthroplasty can evidently improve short-term postoperative clinical outcomes. This first prospective, single-blinded, randomized controlled study showed very good clinical results with comparable pain after FastTrack THA compared to a conventional treatment path. Fast-Track concepts are highly effective in terms of early mobilization and clinical outcome-without incurring a higher risk of complications in the short term.

[SOG-Special Orthopedic Geriatrics : First interim results of a randomized controlled study on integrated orthogeriatric care in elective hip and knee arthroplasty]. / SOG ­ Spezielle Orthopädische Geriatrie : Erste Zwischenergebnisse einer randomisierten kontrollierten Studie zur integrierten orthogeriatrischen Versorgung in der elektiven Hüft- und Kniegelenkendoprothetik.

BACKGROUND: To date, there are no adequate care concepts for geriatric patients undergoing elective orthopaedic surgery in Germany. The Special Orthopaedic Geriatrics (SOG) study evaluates for the first time in Germany the impact of comprehensive orthogeriatric co-management on the outcome of elderly patients with elective hip and knee replacements compared to standard orthopaedic care. METHODS: The interim analysis of the ongoing study included 174 patients; 87 patients were randomized to the intervention group and 87 to the control group. The SOG care model consists of screening, preoperative assessment with preoperative intervention, fast-track surgery and multimodal perioperative care in the orthogeriatric team. The control group received standard orthopaedic care. Mobility, complications, and patient-reported outcome measures after surgery were compared. RESULTS: The SOG group showed a clinically relevant improvement in mobility postoperatively compared to the control group at all time points (p < 0.01). The evaluation of complications showed a significant risk reduction for minor complications (p < 0.01), as well as a clear trend towards a risk reduction for major complications. Patient-reported outcome measures showed a significant improvement in joint function and general health-related quality of life both in the SOG group and the control group. CONCLUSION: Integrated orthogeriatric care models such as SOG could improve the care of geriatric patients in elective orthopaedic surgery in the future and, above all, make it safer.

[Navigation and robotics-current status and future implications]. / Navigation und Robotik ­ status präsens und zukünftige Implikationen.

INTRODUCTION: Both navigation systems and robotics enable greater precision in the implantation of an artificial knee joint. However, they do not improve clinical outcomes. We hypothesized that although implantation of a total knee arthroplasty results in reconstruction of the alignment in the coronal plane, the variable rotational tibial and variable translational femoral and tibial component positioning lead to a change in the remaining alignment parameters of the lower extremity. However, these parameters could be determined using a navigation system or robot and could represent future implications for these systems. METHODS: The kinematics and the position between femur and tibia before and after implantation of a total knee arthroplasty were determined using a navigation system in nine healthy knee joints of Thiel-fixed whole-body cadavers. RESULTS: After arthroplasty, there was no change in the natural coronal alignment. In extension and the early degrees of flexion, the rotational position of the femur relative to the tibia was altered. This also led to a change in the positioning of the medial and lateral epicondyle in relation to the tibia; while both epicondyles were positioned more laterally in relation to the tibia after arthroplasty, the lateral epicondyle was significantly more lateral in relation to the tibia up to 20° of flexion. DISCUSSION: Following arthroplasty of a knee joint using the established technique, a good reconstruction of the coronal alignment was achieved with simultaneous changes in the alignment in both the rotational and translational directions between the femur and tibia. Using navigation as well as robotics, we would be able to quantify all alignment parameters and could achieve an alignment of the components or a reconstruction of the overall alignment in all six degrees of freedom. We might also be able to achieve a clinical advantage or increase the service life even further.

The impact of primary total hip and knee replacement on frailty: an observational prospective analysis.

BACKGROUND: Osteoarthritis is a prevalent condition in frail older adults that requires hip or knee replacement in many patients. The aim of the study was to determine the impact of hip and knee arthroplasty on frailty. METHODS: In this prospective short-term study, we used data from 101 participants of the ongoing Special Orthopaedic Geriatrics (SOG) trial, funded by the German Federal Joint Committee (GBA). Frailty, measured by Fried's Physical Frailty Phenotype (PFP), was assessed preoperatively, 7 days postoperatively, 4-6 weeks and 3 months after hip and knee arthroplasty. ANOVA with repeated measures and post-hoc tests for the subgroups were used for the statistical analysis. RESULTS: Of the 101 participants, 50 were pre-frail (1-2 PFP criteria) and 51 were frail (≥ 3 PFP criteria) preoperatively. In the pre-frail group, the PFP score decreased from 1.56 ± 0.50 (median 2) preoperatively to 0.53 ± 0.73 (median 0) 3 months after surgery (p < 0.001). The PFP score in the frail cohort decreased from 3.39 ± 1.45 (median 3) preoperatively to 1.27 ± 1.14 (median 1) 3 months postoperatively (p < 0.001). While the PFP score of the pre-frail participants increased 7 days after surgery, the PFP score of the frail group decreased significantly. CONCLUSION: Pre-frail individuals often regain robustness and patients with frailty are no longer assessed as frail after surgery. Joint replacement is an effective intervention to improve frailty in hip and knee osteoarthritis. TRIAL REGISTRATION: This study is part of the Special Orthopaedic Geriatrics (SOG) trial, German Clinical Trials Register DRKS00024102. Registered on 19 January 2021.

Better early outcome with enhanced recovery total hip arthroplasty (ERAS-THA) versus conventional setup in randomized clinical trial (RCT).

INTRODUCTION: Numbers of total hip arthroplasty (THA) are steadily rising and patients expect faster mobility without pain postoperatively. The aim of enhanced recovery after Surgery (ERAS) programs in a multidisciplinary setup was to keep pace with the needs of quality and quantity of surgical THA-interventions and patients' expectations. METHODS: 194 patients undergoing THA procedures were investigated after single-blinded randomization to ERAS (98) or conventional setup group (96). Primary outcome variable was mobilization measured with the Timed Up and Go Test (TUG) in seconds. Secondary outcome variables were floor count and walking distance in meters as well as rest, mobilization and night pain on a numerous rating scale (NRS). All variables were recorded preoperatively and daily until the sixth postoperative day. To assess and compare clinical outcome and patient satisfaction, the PPP33-Score and PROMs were used. RESULTS: No complications such as thromboembolic complications, fractures or revisions were recorded within the first week postoperatively in either study group. Compared to the conventional group, the ERAS group showed significantly better TUG (p < 0.050) and walking distance results after surgery up to the sixth, and floor count up to the third postoperative day. On the first and second postoperative day, ERAS patients showed superior results (p < 0.001) in all independent activity subitems. Regarding the evaluation of pain (NRS), PPP33 and PROMS, no significant difference was shown (p > 0.050). CONCLUSION: This prospective single-blinded randomized controlled clinical trial was able to demonstrate excellent outcome with comparable pain after ERAS THA versus a conventional setup. Therefore, ERAS could be used in daily clinical practice.

Influence of bone mineral density on femoral stem subsidence after cementless THA.

INTRODUCTION: Femoral stem subsidence can lead to aseptic loosening after total hip arthroplasty (THA). Low bone mineral density (BMD) is a risk factor for stem subsidence as it can affect the initial stability and osteointegration. We evaluated whether reduced bone mineral density is related to higher subsidence of the femoral stem after primary cementless THA with enhanced recovery rehabilitation. METHODS: 79 patients who had undergone primary cementless THA with enhanced recovery rehabilitation were analyzed retrospectively. Subsidence of the femoral stem was measured on standing pelvic anterior-posterior radiographs after 4-6 weeks and one year. Patient individual risk factors for stem subsidence (stem size, canal flare index, canal fill ratio, body mass index (BMI), demographic data) were correlated. Dual X-ray absorptiometry (DXA) scans were performed of the formal neck and the lumbar spine including the calculation of T-score and Z-score. Patient-reported outcome measures were evaluated 12 months postoperatively. RESULTS: Stem subsidence appeared regardless of BMD (overall collective 2.3 ± 1.64 mm). Measure of subsidence was even higher in patients with normal BMD (2.8 ± 1.7 mm vs. 2.0 ± 1.5 mm, p = 0.05). High BMI was correlated with increased stem subsidence (p = 0.015). Subsidence had no impact on improvement of patient-related outcome measures (WOMAC, EQ-5D-5L and EQ-VAS) after THA. Patients with low BMD reported lower quality of life 12 month postoperatively compared to patients with normal BMD (EQ-5D-5L 0.82 vs. 0.91, p = 0.03). CONCLUSION: Stable fixation of a cementless stem succeeds also in patients with reduced BMD. Regarding stem subsidence, enhanced recovery rehabilitation can be safely applied in patients with low BMD.

Bone Mineral Density is Associated With Adverse Events but not Patient-Reported Outcomes in Total Hip and Knee Arthroplasty.

BACKGROUND: Although osteoporosis is common in patients undergoing elective total hip arthroplasty (THA) and total knee arthroplasty (TKA), its impact on postoperative outcomes has been inadequately studied. The purpose of this study was to evaluate the impact of bone mineral density (BMD) on adverse events and patient-reported outcomes in THA and TKA. METHODS: A series of 1,306 THA and 1,046 TKA patients who had received osteodensitometry were analyzed retrospectively. Rates of readmission, complication, transfusion, and patient-reported outcome were correlated with BMD. Multivariable logistic regression models were used to assess the relationship between osteoporosis and adverse events. RESULTS: Osteoporosis patients showed higher rates of 90-day readmission (THA: 8.5% versus 4.0%, P = .02; TKA: 8.9% versus 4.4%, P = .04) and transfusion (THA: 6.8% versus 1.2%, P < .001; TKA: 5.4% versus 1.5%, P = .005). After THA, rates of complications requiring intensive care management (5.1% versus 0.7%, P < .001) and rates of medical complications (3.5% versus 0.6%, P = .001) were increased. After TKA, rates of surgical complications (2.8% versus 0.8%, P = .04) were increased. Postoperatively, osteoporosis patients improved to comparable patient-reported outcomes as patients who had normal BMD. Multivariable logistic regression analyses revealed osteoporosis as an independent risk factor for readmissions, complications, and transfusions. CONCLUSION: Osteoporosis is a risk factor for adverse events after THA and TKA. Affected patients show similar improvement of patient-reported outcome compared to patients who have normal BMD. As osteoporosis is modifiable, a systematic screening of patients scheduled for THA or TKA should be discussed.

Arthrosis diagnosis and treatment recommendations in clinical practice: an exploratory investigation with the generative AI model GPT-4.

BACKGROUND: The spread of artificial intelligence (AI) has led to transformative advancements in diverse sectors, including healthcare. Specifically, generative writing systems have shown potential in various applications, but their effectiveness in clinical settings has been barely investigated. In this context, we evaluated the proficiency of ChatGPT-4 in diagnosing gonarthrosis and coxarthrosis and recommending appropriate treatments compared with orthopaedic specialists. METHODS: A retrospective review was conducted using anonymized medical records of 100 patients previously diagnosed with either knee or hip arthrosis. ChatGPT-4 was employed to analyse these historical records, formulating both a diagnosis and potential treatment suggestions. Subsequently, a comparative analysis was conducted to assess the concordance between the AI's conclusions and the original clinical decisions made by the physicians. RESULTS: In diagnostic evaluations, ChatGPT-4 consistently aligned with the conclusions previously drawn by physicians. In terms of treatment recommendations, there was an 83% agreement between the AI and orthopaedic specialists. The therapeutic concordance was verified by the calculation of a Cohen's Kappa coefficient of 0.580 (p < 0.001). This indicates a moderate-to-good level of agreement. In recommendations pertaining to surgical treatment, the AI demonstrated a sensitivity and specificity of 78% and 80%, respectively. Multivariable logistic regression demonstrated that the variables reduced quality of life (OR 49.97, p < 0.001) and start-up pain (OR 12.54, p = 0.028) have an influence on ChatGPT-4's recommendation for a surgery. CONCLUSION: This study emphasises ChatGPT-4's notable potential in diagnosing conditions such as gonarthrosis and coxarthrosis and in aligning its treatment recommendations with those of orthopaedic specialists. However, it is crucial to acknowledge that AI tools such as ChatGPT-4 are not meant to replace the nuanced expertise and clinical judgment of seasoned orthopaedic surgeons, particularly in complex decision-making scenarios regarding treatment indications. Due to the exploratory nature of the study, further research with larger patient populations and more complex diagnoses is necessary to validate the findings and explore the broader potential of AI in healthcare. LEVEL OF EVIDENCE: Level III evidence.

The impact of elective total hip and knee arthroplasty on physical performance in orthogeriatric patients: a prospective intervention study.

BACKGROUND: Osteoarthritis is a prevalent condition in older adults that leads to reduced physical function in many patients and ultimately requires hip or knee replacement. The aim of the study was to determine the impact of hip and knee arthroplasty on the physical performance of orthogeriatric patients with osteoarthritis. METHODS: In this prospective study, we used data from 135 participants of the ongoing Special Orthopaedic Geriatrics (SOG) trial, funded by the German Federal Joint Committee (GBA). Physical function, measured by the Short Physical Performance Battery (SPPB), was assessed preoperatively, 3 and 7 days postoperatively, 4-6 weeks and 3 months after hip and knee arthroplasty. For the statistical analysis, the Friedman test and post-hoc tests were used. RESULTS: Of the 135 participants with a mean age of 78.5 ± 4.6 years, 81 underwent total hip arthroplasty and 54 total knee arthroplasty. In the total population, SPPB improved by a median of 2 points 3 months after joint replacement (p < 0.001). In the hip replacement group, SPPB increased by a median of 2 points 3 months after surgery (p < 0.001). At 3 months postoperatively, the SPPB increased by a median of 1 point in the knee replacement group (p = 0.003). CONCLUSION: Elective total hip and knee arthroplasty leads to a clinically meaningful improvement in physical performance in orthogeriatric patients with osteoarthritis after only a few weeks. TRIAL REGISTRATION: This study is part of the Special Orthopaedic Geriatrics (SOG) trial, German Clinical Trials Register DRKS00024102. Registered on 19 January 2021.

[Outcome of joint replacement in patients with underlying rheumatoid disease]. / Outcome nach Gelenkersatz bei Patienten mit rheumatoider Grunderkrankung.

BACKGROUND: Artificial joint replacement is a meaningful treatment option for patients with advanced rheumatic degenerative joint diseases. The aim of this study was to investigate the influence of the underlying rheumatic diseases on postoperative complications and patient-reported outcome (PRO) after elective total joint replacement (TJR). MATERIAL AND METHODS: In a retrospective analysis of 9149 patients with elective total knee or total hip arthroplasty (TKR and THR), complication rates and PRO of patients with and without rheumatic diseases (RD) were compared. Multivariate logistic regression models were used to determine whether the underlying rheumatic disease was an independent risk factor for various complications. RESULTS: In the univariate analyses the RD patients had an increased risk of medical complications (7.1% vs. 5.2%; p = 0.028) and Clavien-Dindo grade IV complications (2.8% vs. 1.8%; p = 0.048) after TJR. This was confirmed in multivariate statistical analyses (p < 0.034). The rates for operative revisions and surgical complications were comparable (2.5% vs. 2.4%; p = 0.485). Analysis of the PRO showed a higher responder rate in patients with RD after TKR (91.9% vs. 84.5%, p = 0.039). In contrast, the responder rate in patients with RD after THR was comparable (93.4% vs. 93.2%, p = 0.584). CONCLUSION: Despite increased postoperative complication rates, patients with underlying rheumatic diseases showed a comparable outcome 1 year after TJR. After TKR the RD patients showed even higher responder rates. Although RD patients are a vulnerable patient group, they can still benefit from joint replacement.

Functional dissection and assembly of a small, newly evolved, W chromosome-specific genomic region of the African clawed frog Xenopus laevis.

Genetic triggers for sex determination are frequently co-inherited with other linked genes that may also influence one or more sex-specific phenotypes. To better understand how sex-limited regions evolve and function, we studied a small W chromosome-specific region of the frog Xenopus laevis that contains only three genes (dm-w, scan-w, ccdc69-w) and that drives female differentiation. Using gene editing, we found that the sex-determining function of this region requires dm-w but that scan-w and ccdc69-w are not essential for viability, female development, or fertility. Analysis of mesonephros+gonad transcriptomes during sexual differentiation illustrates masculinization of the dm-w knockout transcriptome, and identifies mostly non-overlapping sets of differentially expressed genes in separate knockout lines for each of these three W-specific gene compared to wildtype sisters. Capture sequencing of almost all Xenopus species and PCR surveys indicate that the female-determining function of dm-w is present in only a subset of species that carry this gene. These findings map out a dynamic evolutionary history of a newly evolved W chromosome-specific genomic region, whose components have distinctive functions that frequently degraded during Xenopus diversification, and evidence the evolutionary consequences of recombination suppression.

Cost hierarchies and the pattern of product cost cross-subsidization: Extending a computational model of costing system design.

Cost information is critical to ease managers' decisions in daily business, but its provision is informationally demanding and error prone. Effective design choices for costing systems that can reduce errors are the subject of a growing body of research. The computational model by Anand, Balakrishnan, and Labro (2019) collates previous research in a unifying framework, turning it into a potential standard for future studies. This paper uses this framework and aims to investigate the mechanism behind the well-documented empirical pattern of product cost cross-subsidization in a large-scale simulation experiment. According to this pattern, volume-based costing systems bias the costs of high-volume products upward and of low-volume products downward. Although this pattern has important implications for firms and is discussed extensively in the literature, it has not yet been investigated with computational models. As the first objective of this paper, we replicate the original model by following a pattern-oriented model replication approach. The second objective is to study the mechanism behind the pattern of product cost cross-subsidization. We are unable to reproduce it systematically with the original model. However, the pattern emerges when we extend the model to include a simple cost hierarchy with distinct resource consumption types and volume-based cost drivers. This allows us to specify the likely mechanism behind it. Building on these results, we further extend the model with empirical and theory-based ABC cost hierarchies and assess their effect on product cost cross-subsidization. Our results suggest that production environments underpin more diverse cost hierarchies in practice than previously implemented in the model. Overall, we argue that our extension provides relevant insights into the pattern of product cost cross-subsidization, while our replication and extension strengthen the models' credibility and usability for future research.

How Relevant Is the Parallax Effect on Low Centered Pelvic Radiographs in Total Hip Arthroplasty.

The correct cup position in total hip arthroplasty (THA) is usually assessed on anteroposterior low centered pelvic radiographs, harboring the risk of misinterpretation due to projection of a three-dimensional geometry on a two-dimensional plane. In the current study, we evaluate the effect of this parallax effect on the cup inclination and anteversion in THA. In the course of a prospective clinical trial, 116 standardized low centered pelvic radiographs, as routinely obtained after THA, were evaluated regarding the impact of central beam deviation on the cup inclination and anteversion angles. Measurements of the horizontal and vertical beam offset with two different methods of parallax correction were compared with each other. Furthermore, the effect of parallax correction on the accuracy ofmeasuring the cup position was investigated. The mean difference between the two parallax correction methods was 0.2° ± 0.1° (from 0° to 0.4°) for the cup inclination and 0.1° ± 0.1° (from -0.1° to 0.2°) for the anteversion. For a typically intended cup position of a 45° inclination and 15° anteversion, the parallax effect led to a mean error of -1.5° ± 0.3° for the inclination and 0.6° ± 1.0° for the anteversion. Central beam deviation resulted in a projected higher cup inclination up to 3.7°, and this effect was more prominent in cups with higher anteversion. In contrast, the projected inclination decreased due to the parallax effect up to 3.2°, especially in cups with high inclination. The parallax effect on routinely obtained low centered pelvic radiographs is low and not clinically relevant due to the compensating effect of simultaneous medial and caudal central beam deviation.

Ancient human DNA recovered from a Palaeolithic pendant.

Artefacts made from stones, bones and teeth are fundamental to our understanding of human subsistence strategies, behaviour and culture in the Pleistocene. Although these resources are plentiful, it is impossible to associate artefacts to specific human individuals1 who can be morphologically or genetically characterized, unless they are found within burials, which are rare in this time period. Thus, our ability to discern the societal roles of Pleistocene individuals based on their biological sex or genetic ancestry is limited2-5. Here we report the development of a non-destructive method for the gradual release of DNA trapped in ancient bone and tooth artefacts. Application of the method to an Upper Palaeolithic deer tooth pendant from Denisova Cave, Russia, resulted in the recovery of ancient human and deer mitochondrial genomes, which allowed us to estimate the age of the pendant at approximately 19,000-25,000 years. Nuclear DNA analysis identifies the presumed maker or wearer of the pendant as a female individual with strong genetic affinities to a group of Ancient North Eurasian individuals who lived around the same time but were previously found only further east in Siberia. Our work redefines how cultural and genetic records can be linked in prehistoric archaeology.

Isokinetic knee muscle strength comparison after enhanced recovery after surgery (ERAS) versus conventional setup in total knee arthroplasty (TKA): a single blinded prospective randomized study.

PURPOSE: Total knee arthroplasty (TKA) combined with the concept of enhanced recovery is of continued worldwide interest, as it is reported to improve early functional outcome and treatment quality without increasing complications. The aim of the study was to investigate isokinetic knee muscle strength after cemented TKA in combination with an enhanced recovery after surgery (ERAS) compared to a conventional setup. METHODS: In the single blinded prospective randomized study, 52 patients underwent navigated primary cemented TKA within an ERAS (n = 30) or a conventional setup (n = 22). Preoperatively, five days and four weeks after surgery isokinetic knee muscle strength with BIODEX-type measuring device (peak torque in Nm, work in Joules and power in Watt) and subjective patient-related outcome measures (PROMs) were investigated. RESULTS: The ERAS group showed significantly better outcomes in knee flexion at 180°/s (peak torque (Nm) p = 0.047, work (J) p = 0.040 and power (W) p = 0.016) 5 days postoperatively. The isokinetic measuring at knee extension 60°/s and 180°/s demonstrated no significant difference. The PROMs showed that patients were satisfied with the postoperative results in both groups. After 4 weeks, there was no longer a significant difference in isokinetic measuring at knee extension and flexion between the ERAS and conventional group. CONCLUSIONS: TKA with the concept of ERAS improves excellent isokinetic outcome and patient satisfaction. The isokinetic muscle strength measurement can help patients and surgeons to modify expectations and improve patient satisfaction.