Computer Assisted Orthopedic Surgery (CAOS) plays a major role to improve surgical outcomes. Existing navigation rely on optical markers that are fixed to the bones and surgical instruments and tracked with an optical camera in order to provide, during the intervention, an optimal and real-time assistance to the surgeon. However, these solutions have, still today, several drawbacks that limit their wide adoption, in particular, the need to use markers. Based on RGB-D data, we propose to evaluate two algorithms allowing the 3D localization without markers of surgical objects of interest for orthopedics such as bony structures or instruments. The performance of a recent deep-learning (DL)-based algorithm is therefore compared to the Point-Pair Features (PPF) algorithm using a surgical-based database that has been created for this purpose. The global mean error for the DL-based algorithm was 1.28 mm in translation and 1.54° in rotation, surpassing the PPF algorithm. Despite errors need to be reduced, DL-based algorithms have shown promising results.Clinical relevance— Reducing the number of markers for surgical navigation by exploiting RGB-D data would be beneficial as it could reduce the duration of the operation and could make it less invasive. Latest DL-based models to estimate the pose of bony structures and surgical instruments have yielded promising results paving the way toward markerless navigation approaches.

Background Osteoarthritis affects about 528 million people worldwide, causing pain and stiffness in the joints. Arthroplasty is commonly performed to treat joint osteoarthritis, reducing pain and improving mobility. Nevertheless, a significant share of patients remain unsatisfied with their surgery. Personalised arthroplasty was introduced to improve surgical outcomes however current solutions require delays, making it difficult to integrate in clinical routine. We propose a fully automated workflow to design patient-specific implants for total knee arthroplasty. Methods The proposed pipeline first uses artificial neural networks to segment the femur and tibia proximal and distal extremities. Then the full bones are reconstructed using augmented statistical shape models, combining shape and landmarks information. Finally, 77 morphological parameters are computed to design patient-specific implants. The developed workflow has been trained on 91 CT scans and evaluated on 41 CT scans, in terms of accuracy and execution time. Results The workflow accuracy was 0.4±0.2mm for segmentation, 1.0±0.3mm for full bone reconstruction, and 2.2±1.5mm for anatomical landmarks determination. The custom implants fitted the patients’ anatomy with 0.9±0.5mm accuracy. The whole process from segmentation to implants’ design lasted about 15 minutes. Conclusion The proposed workflow allows the establishment of a patient-specific pre-operative planning in a very short time, making it easily available for all patients. It performs a fast and reliable personalisation of knee implants, including CT segmentation, bone modelling, morphological analysis and implant design, without requiring any manual intervention. Combined with efficient implant manufacturing techniques, this solution could help answer the growing number of arthroplasties while reducing complications and improving patients’ satisfaction.

Background From several decades, the evolutions of the Incidence Rate (IR) of Primary Knee Arthroplasties are continuously increasing worldwide and have been widely studied in several countries. Some recent works have highlighted the fact that the IR is following a sigmoid curve composed of an exponential growth followed by a linear phase and finished by a plateau. Our objective is to assess the IR evolution of eleven European countries, representing thus a large proportion of this continent, regarding this sigmoid. Methods IRs of primary knee arthroplasties for Austria, Denmark, Finland, France, Germany, Hungary, Italy, Poland, Spain, Sweden, and the United Kingdom between 2005 and 2019 were retrieved from the EUROSTAT database. Several regression models were fitted to each country’s IRs: Poisson, linear, asymptotic, logistic, and Gompertz regression. For each country and each model, the RMSE (Root Mean Square Error) and R2 were calculated and used to estimate their position with respect to this sigmoid curve. Results The best regression models for knee arthroplasties varied following countries. Logistic and Gompertz regressions had the lowest RMSE and R2 values for Austria, Denmark, Germany, Sweden, and the UK. Hungary, Italy, and Poland favored the Poisson regression model. Finland and Spain presented difficulties in determining the optimal model (linear or Poisson), while France faced challenges in choosing between logistic, Gompertz, and linear regression. Conclusion In conclusion, the growth dynamics of IR differ across European countries. Some countries seem to have already reached a plateau and will therefore experience slight growth in the future.

Contexte En réponse à divers facteurs socioéconomiques, et à l’évolution technologique, les actes d’arthroplastie du genou ont constamment augmenté. Jusqu’à présent, les analyses épidémiologiques menées ont été monopays. Les objectifs de l’article sont : (1) d’identifier les bases de données d’arthroplasties par pays, (2) vérifier la comparabilité internationale des codifications, (3) étudier les tendances épidémiologiques rétrospectives et (4) analyser les projections par pays. L’hypothèse est que les pays suivent des tendances similaires mais décalées dans le temps. Matériel et méthode Une analyse de la littérature de 2005 à 2023 a été réalisée selon les recommandations PRISMA sur “PubMed”, “Web of Science” et “Cochrane”, avec les mots-clés : “Knee+Arthroplasty+Trends+Replacement+Epidemiology”. Seuls les articles avec une analyse nationale, basée sur un référencement reconnu par les systèmes de santé ont été inclus. Résultats Quarante-huit articles, représentant 16 pays, ont été retenus. L’Europe était la plus représentée (47 % des occurrences), suivie des États-Unis (22 %), de l’Asie (20 %), de l’Océanie (8 %) et du Chili (2 %). Les données provenaient de bases de données nationales ou d’échantillons représentatifs extrapolés. Les méthodes d’extraction utilisaient des codes nationaux précis ou des définitions spécifiques. Les taux de croissance en volume et en incidence étaient positifs, mais variaient entre les pays, avec des dynamiques distinctes, tout comme différentes phases de croissance. Les femmes avaient des volumes et des taux d’incidence plus élevés (ratio de sexe 2/3), mais la croissance était plus rapide chez les hommes. Les prévisions futures, basées sur des régressions (poisson, linéaire ou logistique), indiquaient une augmentation des volumes entre +30 % (2030) et +805 % (2050). Conclusion L’analyse des systèmes de recensement a révélé une croissance des arthroplasties du genou dans tous les pays, mais avec des variations d’intensité, dépendant également des périodes. Ces disparités multifactorielles, semblaient suivre un schéma similaire, décalé dans le temps, en fonction du développement économique des pays. Niveau de preuve IV ; revue d’études épidémiologique.

Background In response to various socio-economic factors and technological advancements, knee arthroplasty procedures have steadily increased. To date, epidemiological analyses have been conducted on a single-country basis. The aims of this article are: (1) to identify arthroplasty databases by country, (2) to verify the international comparability of coding, (3) to study retrospective epidemiological trends, and (4) to analyze projections by country. The hypothesis is that countries will follow similar trends, though with varying time lags. Materials and methods A literature review from 2005 to 2023 was conducted following PRISMA recommendations on PubMed, Web of Science, and Cochrane, using the keywords: “Knee + Arthroplasty + Trends + Replacement + Epidemiology.” Only articles featuring national analyses, based on references recognized by healthcare systems, were included. Results Forty-eight articles, representing 16 countries, were selected. Europe was the most represented (47% of occurrences), followed by the USA (22%), Asia (20%), Oceania (8%), and Chile (2%). The data came from national databases or representative extrapolated samples. Extraction methods used precise national codes or specific definitions. Growth rates in volume and incidence were positive but varied between countries, with distinct dynamics and different phases of growth. Females had higher volumes and incidence rates (sex ratio 2/3), but growth was faster in males. Future forecasts, based on regression models (Poisson, linear, or logistic), predicted an increase in volumes of between +30% by 2030 and +805% by 2050. Conclusion The analysis of census systems revealed growth in knee arthroplasties in all countries, but with varying intensities depending on the period. These multifactorial disparities appeared to follow a similar pattern, staggered over time based on the countries' economic development. Level of evidence IV; epidemiological review

ContexteLes actes de prothèses totales d’épaule (PTE) sont en augmentation constante depuis plusieurs décennies aux États-Unis comme en Europe. En France, une croissance de +24,5 % des chirurgies d’épaule a été observée entre 2012 et 2018, mais aucune étude n’a analysé l’évolution des actes de PTE selon le profil des patients. Aussi, nous proposons d’étudier la dynamique des PTE, sur la base des données nationales françaises, pour (1) analyser les tendances de croissance par sexe, âge et niveau de comorbidité des patients, et (2) estimer les projections les plus adaptées du taux d’incidence (TI) à l’horizon 2070.HypothèseNotre hypothèse est qu’en France, il existe une dynamique à la hausse différente pour chaque sexe et catégorie d’âge.Matériel et méthodeL’étude a été menée en France sur la période 2009-2019 à partir de la base de données du Système National des Données de Santé qui répertorie toutes les interventions menées en France. Les patients ont été analysés par sexe, catégorie d’âge (< 65 ans, 65–74 ans, ≥ 75 ans) et état de comorbidité (quatre niveaux). En se basant sur le recueil des actes effectués et les relevés de population de l’Institut national de la statistique et des études économiques, il a été déduit l’évolution des TI pour 100 000 habitants par âge, sexe et comorbidité des patients. Les TI ont été projetés jusqu’en 2070 en utilisant des modèles de projection de types linéaire, Poisson, logistique et Gompertz.RésultatsEntre 2009 et 2019, le TI a augmenté plus fortement chez les hommes avec +155 % (de 6,0 à 15,3) que chez les femmes avec +118 % (de 16,2 à 35,3), et ce pour toutes les classes d’âges. Cette croissance a été la plus importante chez les < 65 ans avec +112 % (de 2,3 à 4,9), tant chez les hommes avec +129 % (de 2,1 à 4,8) que chez les femmes avec +99 % (de 2,5 à 5,0). Sur la période 2012-2019, la proportion de patients avec des comorbidités peu sévères a augmenté de +92 % (de 5 435 à 10 410 PTE, soit de 56 % à 61 % du total des actes), à la différence des autres classes. Tous les modèles de projection modélisent les données 2009-2019 avec de faibles écarts. Toutefois, la projection logistique est la plus probable, avec un TI augmentant de +45 % pour la population globale d’ici 2070 (de 17 175 à 25 338 PTE) et se stabilisant dès 2050.ConclusionLe TI a connu une nette croissance dans la population globale, comme dans toutes les catégories d’âge, de sexe et de comorbidité, avec une augmentation des actes plus forte chez les <65 ans et les 65–74 ans, ainsi qu’un glissement vers des patients à plus faible comorbidité. Selon les projections, le TI continuerait d’être plus fort chez les patients plus âgés, excepté chez les hommes pour qui le TI des 65–74 ans dépasserait celui des ≥ 75 ans aux alentours de 2030. À plus long terme, l’évolution du TI s’inscrit dans une dynamique de type logistique, avec l’atteinte d’un plateau vers 2050. Face à cette demande croissante en PTE, une augmentation de la charge en soins sera à prévoir.Niveau de preuveIV; Étude épidémiologique descriptive.

Our research aims to enhance smart orthopedic knee implants used in Total Knee Arthroplasty (TKA). With the projected quadrupling of TKA demand by 2030 due to factors like aging populations, rising obesity rates, and broader indications for younger patients, our focus is on instrumented medical implants to measure knee parameters. In this paper, we report the optimization of a wireless power transmission system for powering smart knee implants, employing an established HF Near-field Resonant Inductive Coupling (NRIC) technique at 13.56MHz inside the stem of a tibial knee implant. We propose a pragmatic optimization approach in this study, guided by the integration constraints of a knee implant and validated by orthopedic surgeons through cadaveric specimen testing. Finite Element simulations guided the selection of a frontal 3-turn solenoid (called "paperclip" coil) at the Rx side, located at the tip of the stem, which demonstrated balanced performance metrics and reasonable volume occupancy (1.6 cm(3)). Power transfer measurements were conducted through conductive solutions mimicking skin, muscle, and bones. At 13.56MHz , a power transfer efficiency eta of 30% and 7.5% ( 300mW and 75mW at 1W input power) was achieved at Tx-Rx distances of 25mm and 40mm respectively. The proposed solution was implanted in a cadaveric specimen : 250mW was obtained at an estimated 30mm distance for an input power of 1W at the Tx side. For the same distance, we also performed a successful DC power provision up to 64mW at 3V DC and data transfer functions at 26kbits(-1) in the cadaver. The proposed system, with its integration strategy, holds promise in powering advanced sensor functions, contributing to the identification and monitoring of postoperative complications and potentially reducing the need for long-term revisions.

In this work, we introduce the design and fabrication of an innovative multi-sensor system integrated into a knee implant, aimed at the early detection of postoperative complications. This system incorporates pH and temperature sensors for infection detection, accelerometers for measuring flexion angles, and force and moment sensors to identify postoperative complications, particularly mechanical issues. A 13.56 MHz RFID-based system was employed for power and data transmission. Collaborative efforts with clinicians and project partners were crucial in designing, testing, and validating the prototype, with initial experiments conducted on cadaveric specimens.

BACKGROUNDTo address the increasing global demand for Total Knee Arthroplasty and reduce the need for revisions, several technologies combining 3D planning and artificial intelligence have emerged. These innovations aim to enhance customization, improve component positioning accuracy and precision. The integration of these advancements paves the way for the development of personalized and connected knee implant.QUESTIONS/PURPOSESThese groundbreaking advancements may necessitate changes in surgical practices. Hence, it is important to comprehend surgeons' intentions in integrating these technologies into their routine procedures. Our study aims to assess how surgeons' preferences will affect the acceptability of using this new implant and associated technologies within the entire care chain.METHODSWe employed a Discrete Choice Experiment, a predictive technique mirroring real-world healthcare decisions, to assess surgeons' trade-off evaluations and preferences.RESULTSA total of 90 experienced surgeons, performing a significant number of procedures annually (mostly over 51) answered. Analysis indicates an affinity for technology but limited interest in integrating digital advancements like preoperative software and robotics. However, they are receptive to practice improvements and considering the adoption of future sensors.CONCLUSIONSIn conclusion, surgeons prefer customized prostheses via augmented reality, accepting extra cost. Embedded sensor technology is deemed premature by them.

The Ouest Data Hub (ODH) a project lead by GCS HUGO which is a cooperation group of University Hospitals in the French Grand Ouest region represents a groundbreaking initiative in this territory, advancing health data sharing and reuse to support research driven by real-world health data. Central to its structure are the Clinical Data Warehouses (CDWs) and Clinical Data Centers (CDCs), essential for analytics and as the linchpin of the ODH's status as an interregional Learning Health System. Aimed at fostering innovation and research, the ODH's collaborative and multi-institutional model effectively utilizes both local and shared resources. Yet, the path is not without challenges, especially in data quality and interoperability, where ongoing harmonization and standard adherence are critical. In 2023, this facilitated access to extensive health data from over 9.3 million patient records, demonstrating the ODH's capacity for both monocentric and multicentric research across various clinical fields, in close collaboration with physicians. The integration of healthcare professionals is crucial, ensuring data's clinical relevance and guiding accurate interpretations. Future expansions of the ODH to new hospitals and data types promise to enhance its model further, already inspiring similar frameworks across France. This scalable model for health data ecosystems showcases the ODH's potential as a foundation for national and supranational data sharing efforts.

Image muscle segmentation is useful to quantitatively assess musculoskeletal diseases by extracting biomarkers such as shape, texture and water diffusivity metrics. Although volumetric manual segmentation is time consuming and a bottleneck in practice, fully automatic approaches are still in progress to reach an acceptable accuracy. In this paper, we provide a robust semi-automated tool to segment two musculoskeletal systems, i.e. thigh and shoulder in MRI and CT modalities, respectively. The tool only needs a few manually labelled cross-sections to build a directed graph-structure of corresponding points between the successive spaced slices. The boundaries of each muscle are obtained by performing a spline interpolation based on the directed graph-structure. Each muscle label and its corresponding 3D mesh are deduced using post-processing techniques. We evaluated the tool on 26 MRI thighs and 16 CT shoulders. Three metrics along with inter-muscle overlapping were employed to evaluate the tool by comparison to an expert manual segmentation and a publicly available tools (ITK-SNAP, 3D Slicer). The results showed a mean Dice 0.988±0.003, and Hausdorff Distance 4.86±1.67 mm in comparison to the manual reference for thigh muscle segmentation, and a mean Dice 0.961±0.005 and Hausdorff Distance 2.42±0.79 mm for shoulder muscle segmentation, outperformed the other methods. The tool is proposed as slicer module available at https://github.com/latimagine/SlicerSpline.

INTRODUCTION:The pelvis plays a major role in the orientation of total hip arthroplasty (THA) implants and consequently, on the postoperative stability of the new hip joint. The relationship between the spine and pelvis affects the functional orientation of the acetabular cup, although this relationship differs between individuals and the positions encountered in everyday life. We believe this should be factored in when planning the THA procedure. This led us to conduct an in vivo ultrasound study to document the values of pelvic tilt in standing, sitting and lying positions in patients who have advanced hip osteoarthritis, before and after they undergo THA. HYPOTHESIS:The pelvic tilt when standing, sitting and lying supine does not change significantly after THA. MATERIALS AND METHODS:The pelvic tilt, defined as the angle between the anterior pelvic plane and a vertical line was measured using an ultrasound device in 30 patients before the THA procedure and again 6 months later in standing, sitting and lying positions. The measurements were done during an office visit with the patient on an examination table for the lying position, on a chair for the sitting position and with the heels and occiput against the wall for the standing position. RESULTS:The preoperative and 6-month postoperative pelvic tilt were -5.6̊±10.4̊ [-30.6̊; 11.7̊] and -5.8̊±7.9̊ [-20.6̊; 10.4̊] (p=0.4129) when standing, -44.5̊±6.10 [-53.8̊; -23.9̊] and -43.5̊±6.9̊ [-54.4̊; -17.3̊] (p=0.5760) when sitting, -88.3̊±5.1̊ [-99.3̊; -78.7̊] and -87.9̊±5.9̊ [-97.6̊; -72.4̊] (p=0.6106) when lying supine, respectively. There was no significant difference in the pelvic tilt before and 6 months after THA procedure. Variations of±5̊; ±5-10̊; ±10-15̊ and 15-20̊ were found in 72% (18); 20% (5); 4% (1) and 4% (1) of patients when lying supine, 56% (14); 36% (9); 8% (2); 0% (0) of patients when standing and 76% (19); 24% (6); 0% (0); 0% (0) when sitting. The mean variation for each patient between the preoperative and 6 months postoperative measurement was 4.8±3.4̊ [0.8̊; 10.4̊] (p=0.4129), 3.5±2.3̊ [0.2̊; 9.1̊] (p=0.5760), and 4.6̊±3.2̊ [1.2̊; 15.4̊] (p=0.6106) for the standing, sitting and lying positions respectively. CONCLUSION:The pelvic tilt does not significantly change 6 months after THA. Taking into account the various positions used in everyday life may help to optimize the implant position. We have described the use of an affordable, accurate and non-irradiating device that provides fast and easy measurements of pelvic tilt in various positions. LEVEL OF EVIDENCE:IV.

Les arthroplasties totales du genou (PTG) sont en augmentation constante depuis plusieurs décennies en Europe et aux USA. Bien qu’en progression dans tous les pays, leur croissance est inégale : faible en Europe du Nord et centrale, en ralentissement aux USA et exponentielle au Royaume-Uni. Pour la France, une croissance de +32,2 % des actes d’arthroplasties unicompartimentales et totales du genou a été recensée entre 2012 et 2018, mais aucune étude n’a focalisé sur l’évolution des actes de PTG et l’évolution du statut des malades qui bénéficient d’une PTG. Aussi, nous avons ainsi mené sur la base des données nationales françaises une étude des actes pour déterminer : 1) l'évolution des tendances de croissance par sexe et par âge, (2) l'observation ou non d'un rajeunissement, (3) l’évolution de l’état de comorbidité des patients lors de l’opération, et (4) la stabilisation future du taux d'incidence ou pas et la prévision pour 2050. Notre hypothèse était qu’en France, il existait une dynamique à la hausse différente pour chaque sexe. L’étude a été menée en France sur la période 2009-2019 pour chaque sexe et tranche d’âge. Les données sont issues de la base de données du SNDS (Système National des Données de Santé), qui regroupe toutes les interventions menées en France. En se basant sur le recueil des actes effectués, il a été déduit (1) les taux d’incidence et leur évolution et (2) L’évaluation indirecte de l’état de comorbidité du patient. En utilisant des modèles de projection de types linéaire, Poisson et logistique, les taux d’incidence ont été projetés aux années 2030, 2040 et 2050. Une augmentation du taux d’incidence plus forte entre 2009 et 2019 est observée pour les hommes, de 71,2 à 122,9 (soit +73 %) par rapport aux femmes de 124,2 à 181 (soit +46 %), qui se constate dans toutes les classes d’âges. Néanmoins, la croissance est plus importante chez les moins de 65 ans, tant chez les hommes de 20,9 à 37,9 (soit +82 %) que les femmes de 33,6 à 51,3 (soit +53 %). Sur la période, la proportion des patients avec des comorbidités peu sévères augmentait (de 40 093 à 67 430 PTG, soit de 53,1 % à 65,7 % du total des actes), à la différence des autres classes. Tous les modèles de projection sont validés. Toutefois, tant chez les hommes que les femmes, une projection logistique de +33 % d’ici 2050 (soit 151 575 PTG), avec l’atteinte d’un plateau vers 2030 est la plus probable. Bien que la croissance soit plus forte chez les hommes par rapport aux femmes, les deux sexes suivent une évolution similaire avec une augmentation des actes plus élevée chez les moins de 65 ans et un glissement vers des patients à plus faible comorbidité. A plus long terme, l’évolution du taux d’incidence s’inscrit dans une dynamique de type logistique, avec l’atteinte d’un plateau vers 2030. Face à cette demande croissante, une augmentation de la charge en soins sera à prévoir. IV, Étude épidémiologique descriptive.

OBJECTIVES:Early identification of mechanical complications of total knee arthroplasties is of great importance to minimize the complexity and iatrogenicity of revision surgeries. There is therefore a critical need to use smart knee implants during intra or postoperative phases. Nevertheless, these devices are absent from commercialized orthopaedic implants, mainly due to their manufacturing complexity. We report the design, simulations and tests of a force and moments sensor integrated inside the tibial tray of a knee implant. METHODS:By means of a "tray-pillar-membrane" arrangement, strain gauges and metal additive technology, our device facilitates the manufacturing and assembly steps of the complete system. We used finite element simulations to optimize the sensor and we compared the simulation results to mechanical measurements performed on a real instrumented tibial tray. RESULTS:With a low power acquisition electronics, the measurements corroborate with simulations for low vertical input forces. Additionally, we performed ISO fatigue testings and high force measurements, with a good agreement compared to simulations but high non-linearities for positions far from the tray centre. In order to estimate the center of pressure coordinates and the normal force applied on the tray, we also implemented a small-size artificial neural network. CONCLUSION:This work shows that relevant mechanical components acting on a tibial tray of a knee implant can be measured in an easy to assemble, leak-proof and mechanically robust design while offering relevant data usable by clinicians during the surgical or rehabilitation procedures. SIGNIFICANCE:This work contributes to increase the technological readiness of smart orthopaedic implants.

OBJECTIVES:A new ultrasound-based device is proposed to non-invasively measure the orientation of the scapula in the standing position to consider this parameter for Total Shoulder Arthroplasty. The aim of this study was to assess the accuracy and reliability of this device.METHODS:Accuracy was assessed by comparing measurements made with the ultrasound device to those acquired with a three-dimensional (3D) optical localization system (Northern Digital, Canada) on a dedicated mechanical phantom. Three users performed 10 measurements on three healthy volunteers with different body mass (BMI) indices to analyze the reliability of the device by measuring the intra and interobserver variabilities.RESULTS:The mean accuracy of the device was 0.9°± 0.7 (0.01-3.03), 1.3°± 0.8 (0.03-4.55), 1.9°± 1.5 (0.05-5.76), respectively, in the axial, coronal, and sagittal planes. The interobserver and intraobserver variabilities were excellent whatever the BMI and the users experience.CONCLUSIONS:The device is accurate and reliable enough for the measurement of the scapula orientation in the standing position.

Background: The number of Total Knee Arthroplasty (TKA) procedures has been rising steadily for several decades in Europe and the USA. The increase varies in pace across countries, with a gradual climb in northern and central Europe, a slowing in the USA, and an exponential surge in the UK. In France, a 32.2% rise in the number of TKA and unicompartmental knee arthroplasty procedures was documented between 2012 and 2018. However, no study has focussed specifically on changes in both TKA procedures and the features of TKA patients. The objective of this study was to use the French national healthcare database to evaluate (1) increases in TKA procedures according to sex and age, (2) whether TKA is being performed at increasingly younger ages, (3) whether the comorbidity profile at TKA is changing, and (4) whether the TKA incidence rate will stabilise in the future, with a projection for 2050. Hypothesis: In France, the number of TKA procedures is rising in both males and females but the pace of the increases differs between sexes. Material and method: This study used data collected in France in 2009-2019, separately for different age groups and for males and females, in the French national healthcare database (Systeme national des donnees de sante, SNDS) that collects information on all surgical procedures performed nationwide. Based on information about the TKA procedures, we determined (1) the TKA incidence rates with their time trends and (2) indirectly, the comorbidity profiles of the patients at TKA. Linear, Poisson, and logistic models were built to predict incidence rates in 2030, 2040, and 2050. Results: Between 2009 and 2019, the TKA incidence rate showed a steeper increase in males than in females (from 71.2 to 122.9 [+73%] vs. 124.2 to 181.0 [+46%], respectively). Although this increase was replicated in all age groups, it was sharper in patients younger than 65 years, in both males and females (from 20.9 to 37.9 [+82%] and 33.6 to 51.3 [+53%], respectively). During the study period, the number and proportion of patients increased in the group with mild comorbidities (from 40 093 to 67 430 TKAs, i.e., from 53.1% to 65.7% of all TKAs) but not in the other comorbidity groups. All projection models were validated. Nonetheless, the most likely scenario, provided by the logistic model, is a 33% rise by 2050 in both males and females (i.e., to 151 575 TKA procedures) with a plateau starting around 2030. Conclusion: Although the increase in TKA procedures is more marked in males than in females, the trends are similar in both sexes, with a sharper rise in the group younger than 65 years and a shift toward patients with milder comorbidities. In the longer term, incidence rate trends follow logistic dynamics, with a plateau starting around 2030. To meet the increasing demand, a corresponding development in relevant healthcare resources must be planned. (c) 2022 Elsevier Masson SAS. All rights reserved.

Background: The impact of implanting cementless femoral stems in varus alignment on long-term mechanical complications remains poorly defined in the literature. The aim of our study was to compare survivorship and functional and radiographic outcomes of stems in varus alignment to those in neutral alignment with and average follow-up of 10 years.Methods: This single-center, multisurgeon, retrospective case-control study compared a group of 105 total hip arthroplasty (THA) patients who had varus stem alignment (Varus Stem) to a matching group of 105 THA patients who had neutral stem alignment, operated on between January 2007 and December 2012. The primary outcome measure was implant survival. Secondary outcomes included functional (Harris Hip Score, Postel Merle d'Aubigne ⠁ Score, thigh pain, dislocation and hip range of motion) and radiographic outcomes (radiolucency, osseointegration, heterotopic ossification, subsidence, and stress shielding).Results: There was no significant difference in implant survival between the 2 groups with 95.7% (& PLUSMN;2.46) in the Varus Stem group versus 97.7% (& PLUSMN;1.64) in the Neutral Stem group (P 1/4 .41) after an average follow-up of 10 years. There was no significant difference in clinical and radiographic outcomes between groups.Conclusion: Cementless femoral stems in varus alignment were not the cause of mechanical complica-tions with an average follow-up of 10 years. The comparison between groups in terms of implant sur-vival, functional, and radiographic outcomes does not show any significant differences. Positioning a femoral stem in varus alignment may be an alternative for surgeons wishing to restore preoperative offset and to ensure satisfactory hip stability. & COPY; 2022 Elsevier Inc. All rights reserved.

BACKGROUND:Over the past decades, total shoulder arthroplasty (TSA) procedures have steadily increased in the United States and Europe. In France, the number of shoulder surgeries rose by 24.5% between 2012 and 2018, but no study has yet analyzed TSA trends based on patient characteristics. Therefore, the aim of our study was to use the French healthcare database to (1) analyze growth trends based on the patient's sex, age, and comorbidity profile and (2) estimate the most appropriate incidence rate (IR) projections to the year 2070. HYPOTHESIS:We hypothesize that in France, the upward trends are different for each sex and age group. MATERIALS AND METHODS:This study was conducted in France from 2009 to 2019 based on the French healthcare database (SNDS), which contains all nationwide procedures. Patients were analyzed by sex, age group (<65 years, 65-74 years, ≥75 years), and comorbidity profile (4 levels). IR trends per 100,000 population were inferred by patient age, sex, and comorbidity using data from the French hospital discharge database (PMSI) and population forecasts and censuses from the French National Institute of Statistics and Economic Studies (INSEE). Linear, Poisson, logistic, and Gompertz projection models were created to forecast IRs to the year 2070. RESULTS:Between 2009 and 2019, there was a sharper increase in IR in males (+155%; from 6.0 to 15.3) than in females (+118%; from 16.2 to 35.3) across all age groups. This increase was most significant in those younger than 65 years (+112%; from 2.3 to 4.9), in both males (+129%; from 2.1 to 4.8) and females (+99%; from 2.5 to 5.0). From 2012 to 2019, the proportion of patients with mild comorbidities increased by +92% (from 5,435 to 10,410 TSAs, i.e., from 56% to 61% of total procedures), unlike the other comorbidity profiles. All the projections modeled the data from 2009 to 2019 with minor deviations. However, the logistic projection was the most likely, with a 45% increase in the IR for the overall population by 2070 (from 17,175 to 25,338 TSAs), which will start to plateau in 2050. CONCLUSION:The IR has risen sharply in the overall population, as in all age, sex, and comorbidity categories, with the most significant growth seen in the<65 and 65-74 age groups and a shift toward patients with milder comorbidities. According to our projections, the IR will continue to be more significant in older patients, except for males, for whom the IR for those 65 to 74 years old will exceed that of those 75 and older around 2030. In the longer term, the IRs follow a logistic trend, reaching a plateau around 2050. Therefore, an increase in healthcare burden is to be expected to meet the growing demand for TSAs. LEVEL OF EVIDENCE:IV; Descriptive epidemiological study.

Three-dimensional printing is a technology that has been developed and applied in several medical specialties, especially orthopedic surgery. Knee arthroplasty is the most commonly performed procedure. To fit the morphology of each knee, surgeons can choose between different standardized off-the-shelf implant sizes or opt for customized 3D-printed implants. However, routine adoption of the latter has been slow and faces several barriers. Existing studies focus on technical improvements or case studies and do not directly address the surgeon's perspective. Our study invited surgeons to express themselves freely and answer the question "What do you think about the manufacture of a prosthesis by 3D printing?". The questionnaire was completed by 90 surgeons. On average, they had more than 10 years of experience (52, 57.8% ± 10.2%), worked in public hospitals (54, 60% ± 10.1%), and performed between 0 and 100 prostheses per year (60, 66.7% ± 9.7%). They also reported not using planning software (47, 52.2% ± 9.7%), navigation systems, or robots (62, 68.9% ± 9.6%). Regarding the use of technological innovation, they agreed on the extra surgical time needed (67, 74.4% ± 9.0%). The answers obtained were classified according to two criteria: (i) opinions, and (ii) motivations. Among the respondents, 51 (70% ± 9.5%) had positive and 22 (30% ± 9.5%) had negative opinions about 3D printing. The motivations were distributed among seven categories (surgery, materials, costs, logistics, time, customization, and regulatory) and mainly related to "pre-surgery" and "post-surgery" concerns. Finally, the results showed that the use of navigation systems or robots may be associated with a more positive view of 3DP. The purpose of our study was to examine knee surgeons' perceptions of 3DP at a time of significant expansion of this technology. Our study showed that there was no opposition to its implementation, although some surgeons indicated that they were waiting for validated results. They also questioned the entire supply chain, including hospitals, insurance companies, and manufacturers. Although there was no opposition to its implementation, 3D printing is at a crucial point in its development and its full adoption will require advances in all areas of joint replacement.

The usual safe zone for cup orientation in THA is not suitable for all patients, as the pelvic tilt varies with the movements of daily activities. A new Functional Safe Zone (FSZ) is proposed that considers the pelvic tilt in different positions. The aims of this study were to validate the proposed FSZ and to evaluate how the pelvic mobility impact it. We measured the pelvic tilts of 30 patients when standing, sitting and supine, using our ultrasound-based device and computed their FSZs. The FSZs accuracy was assessed using a Computer-Aided-Design (CAD) software. The pelvic mobility influence onto the FSZ was assessed by jointly analysing the patients’ FSZs and their pelvic tilt difference between positions. The true FSZ provided by the CAD software and the estimated FSZ were similar by 92% and differed by less than 0.5◦ at borders and at the mean orientation. Patients with stiff pelvic mobility obtained small FSZs, and conversely, patients with large pelvic tilt variations between positions obtained large FSZs. The proposed method allows the computation of a patient-specific FSZ without requir- ing additional X-ray or CT images. Patients having a low pelvic mobility with a higher risk of postoperative instability could be better managed using this FSZ.