Abstract The last decade has seen a significant growth in the market for alloys used for implants, especially for those intended for orthopedic implants. Research into biodegradable magnesium-based alloys has made great strides in this period, so huge progress has been made in their use in the medical industry. The important factors that led to the intensification of research in this regard, were social but also economic, wanting to improve the quality of life, by reducing the use of conventionally permanent metallic implants (stainless steel, cobalt-based alloys, and titanium alloys) which involve the second implant removal surgery and other undesirable effects (stress shielding and metal ion releases), with a negative impact on the emotional and physical condition of patients, and by significantly reducing the costs for both the patient and the health system in the field of orthopedics. This paper refers to the impact and importance of biodegradable Mg alloys, reviewing the beginning of their development, the significant characteristics that make them so desirable for such applications (orthopedic implants) but also the characteristics that must be modulated (corrosion rate and mechanical properties) to arrive at the ideal product for the targeted application. It highlights, in detail, the mechanism and aspects related to the corrosion behaviour of Mg alloys, electrochemical characterization techniques / methods, as well as strategies to improve the corrosion behaviour and mechanical properties of these types of biodegradable alloys. The means of optimization, the category and the effect of the alloying elements, the design criteria, the requirements that the implants of biodegradable alloys Mg-based must meet and the aspects related to their efficiency are also presented. Finally, the potential applications in the specialized clinics, as well as the final products currently used and made by important prestigious companies in the world are approached.
Venous thromboembolism (VTE) is defined as the obstruction, partial or complete, of one or more veins of deep circulation. It is a condition that can lead to a deterioration in his state of health until death, manifesting as deep vein thrombosis (DVT) or pulmonary embolism (PE). The major orthopedic surgery and the surgical oncology are frequently associated with thromboembolic complications, because of conditions that are often critical in these patients. It is estimated that in Italy DVT has an incidence that varies between 50 and 150 new cases per 100,000 population, while the prevalence would be between 2.5 and 5%. In the absence of thromboprophylaxis, the orthopedic surgery lead to a high increased risk of VTE. In elective hip replacement, in the absence of prophylaxis, the incidence of DVT and of fatal PE is about 50% and 2% respectively. In elective knee arthroplasty the risk of venous thromboembolic complications is even higher. It is estimated that 56.2% of the costs of prophylaxis with Low Molecular Weight Heparin (LMWH) in patients undergoing major orthopedic surgery are attributable to the cost of drugs (about € 200), followed (with 44.8%) by the cost of administration (approximately € 159). The average total cost/day was estimated at € 8 per patient. In Italy, it has been estimated an annual cost for new cases between 215 and 260 million €. The clinical advantages of the New Oral Anticoagulants (NOA) appear to be substantially clear, the major concern with regard to their reimbursement is therefore linked to the financial impact, due to the higher cost per day of the NOA compared with LMWH. To this end, it was built a model of budget impact, in the perspective of the Italian NHS, from the data related to cases of major surgical orthopedic procedures and a meta-analysis on the pivotal RCT, which aims to measure the differential effects in terms of prevention of VTE. The results show that the financial impact of the NOA in the prophylaxis of major orthopedic surgery is not particularly relevant. In fact, the major pharmaceutical costs that, at national level, amount to € 10.8 mil. (€ 15.2 mil. in the case of prolonged prophylaxis in knee operations) would be more than offset by savings in terms of fewer treatments of VTE, which is based on the assumption of more than 4,000 cases, up to about 6,600 in hypothesis best efficacy.
ABSTRACT Objective A comprehensive understanding of the anatomical structure of the femur is crucial for optimizing surgical approaches and improving prosthesis design. This study aims to conduct a thorough analysis of the anatomical structure of the Chinese femur using statistical shape models (SSM), thereby providing scientific evidence for clinical applications. Method In this study, the femoral CT data of 209 Chinese patients were collected for detailed 3D reconstruction to obtain a 3D model of the bilateral femur. Advanced 3D model alignment techniques and dense homologous mesh mapping methods were used to ensure the high accuracy and consistency of the models. Three‐dimensional statistical shape modeling (SSM) and principal component analysis (PCA) methods were used to extract the main patterns of femoral morphology changes and further analyze the femoral morphology changes. On this basis, the effects of gender differences on femur morphology were further comparatively analyzed. Results This study successfully established a statistical shape model of the femur in the Chinese population and extracted patterns of femoral shape variation through principal component analysis. The first six principal components shape change patterns accounted for 82.7%, 3.4%, 2.7%, 2.5%, 2.0%, and 1.5% of the total change, respectively. The model of variation for each of the first six principal components accounted for more than 1% of the total anatomical variance and together explained 94.8% of the variance. PC01, PC02, PC03, PC04, and PC06 exhibited significant differences between sexes (p < 0.05). Conclusion By constructing a three‐dimensional statistical shape model of the femur, this study reveals individual morphological variations as well as differences based on sex. This model not only deepens the understanding of the anatomical morphology of the Chinese femur but also provides an important scientific basis for the optimization of clinical surgical plans and the improvement of prosthesis design.
We study cosmetic surgeries on a knot in a homology sphere. Several constraints on knots and surgery slopes to admit such surgeries are given. Our main ingredient is the rational surgery formula of the Casson--Walker invariant for 2-component links in the 3-sphere.
Ali Bahari Malayeri, Matthias Seibold, Nicola Cavalcanti
et al.
This study aims to advance surgical phase recognition in arthroscopic procedures, specifically Anterior Cruciate Ligament (ACL) reconstruction, by introducing the first arthroscopy dataset and developing a novel transformer-based model. We aim to establish a benchmark for arthroscopic surgical phase recognition by leveraging spatio-temporal features to address the specific challenges of arthroscopic videos including limited field of view, occlusions, and visual distortions. We developed the ACL27 dataset, comprising 27 videos of ACL surgeries, each labeled with surgical phases. Our model employs a transformer-based architecture, utilizing temporal-aware frame-wise feature extraction through a ResNet-50 and transformer layers. This approach integrates spatio-temporal features and introduces a Surgical Progress Index (SPI) to quantify surgery progression. The model's performance was evaluated using accuracy, precision, recall, and Jaccard Index on the ACL27 and Cholec80 datasets. The proposed model achieved an overall accuracy of 72.91% on the ACL27 dataset. On the Cholec80 dataset, the model achieved a comparable performance with the state-of-the-art methods with an accuracy of 92.4%. The SPI demonstrated an output error of 10.6% and 9.86% on ACL27 and Cholec80 datasets respectively, indicating reliable surgery progression estimation. This study introduces a significant advancement in surgical phase recognition for arthroscopy, providing a comprehensive dataset and a robust transformer-based model. The results validate the model's effectiveness and generalizability, highlighting its potential to improve surgical training, real-time assistance, and operational efficiency in orthopedic surgery. The publicly available dataset and code will facilitate future research and development in this critical field.
ABSTRACT Purpose Nucleus augmentation has been proposed as an early‐stage intervention for intervertebral disc degeneration and involves the injection of a biomaterial into the nucleus to restore disc height and functionality. The aim of this work was to identify clinically relevant quantitative measures that indicate the mechanical performance of the disc following nucleus augmentation. Method Bovine tail bone‐disc‐bone units (n = 22) were mechanically tested under cyclic loading sequentially in native, artificially degenerated, and treated states. Treatment involved injection of a peptide‐glycosaminoglycan mixture into the degenerated disc to a predetermined load using a syringe driver with an integrated force sensor. The stiffness restoration of the treatment was determined by comparing the biomechanical behavior of the native state to the treated state of each disc. The stiffness restoration was then compared against clinically quantifiable parameters. Results No significant biomechanical differences were observed between the native and treated states, but both were significantly different from the degenerated state. The force delivered during injection was found to ramp to a steady state, followed by a final rapid increase; however, all measures associated with injection force poorly correlated with the level of stiffness restoration. Volume injected and change in disc height from injection had the strongest relationship to stiffness restoration. Conclusion This work showed that measuring the injection force for injectable treatments of the disc can provide lower and upper limits for delivery, but direct measures are stronger indicators of disc stiffness restoration.
Alex N. Karanja MBChB, Albert Ho-Huynh MBBS, Tom Walsh PhD
et al.
Background: Ankle fractures are common orthopaedic injuries, and their management is primarily determined by fracture stability. The Lauge-Hansen classification system categorizes fractures according to mechanism of injury and ligaments involved. Supination external rotation (SER) type 2 fractures correspond to stable weber B fractures and are traditionally treated nonoperatively, whereas SER 3 and SER 4 fractures, characterized by syndesmosis disruption, typically require surgical intervention. We hypothesize that some apparently stable injuries may involve additional structures, challenging the conventional treatment approach. This study aims to determine the prevalence of SER 3 and SER 4 ankle injuries among radiographically stable SER 2 fractures. Method: The study used baseline data from a longitudinal cohort conducted at Gold Coast Hospital and Health Service (GCHHS). Patients attending the GCHHS fracture clinic with radiographically stable SER 2 fractures were invited to participate. Those meeting the eligibility criteria underwent ankle magnetic resonance imaging (MRI) to evaluate the integrity of syndesmotic and ankle ligaments. Results: Fifty-six participants were recruited, 38 (68%) female and 18 (32%) male, with a mean age of 47.2 years. All had stable syndesmoses on radiographic assessment and diagnosed with stable SER 2 ankle fractures. MRI scans revealed that 71% (n = 40) met the criteria for SER 2 injuries, 25% (n = 14) for SER 3 injuries with complete ruptures of posterior inferior tibiofibular ligament (PITFL), and 4% (n = 2) for SER 4 injuries with PITFL and deltoid ligament (DL) ruptures. These results challenge the assumption that radiographically stable SER 2 fractures are consistently stable in terms of additional structures involved. Conclusion: The study highlights that a considerable proportion of seemingly stable ankle fractures involve more structures than previously thought. This suggests the management of SER 3 and SER 4 injuries could include nonoperative treatment. Level of Evidence: Level III, cohort study.
Elio Paris, Giacomo De Marco, Oscar Vazquez
et al.
Fibrous dysplasia is a congenital, non-inherited, benign intramedullary bone lesion in which the normal bone marrow is replaced by abnormal fibro-osseous tissue. The disorder can be monostotic (involving a single bone) or polyostotic (involving multiple bones). As the abnormal fibro-osseous tissue compromises the mechanical strength of bone, it can result in pain, deformity, fractures, or abnormalities in bone mechanics with inappropriate bone alignment. This narrative review attempts to summarize more than 20 years of observations of patients with FD to help pediatric orthopedists establish a care framework that can improve its identification, understand the impact that endocrinopathies can have on its clinical presentation, and optimize the management of bone disorders. Our focus is specifically on orthopedic manifestations of FD and modern management alternatives. The past 20 years have provided major advances in understanding of fibrous dysplasia (FD), and it is clear that the pediatric orthopedist's role remains highly relevant in the management of all types of FD. Surgical treatment remains appropriate when pain is unresponsive to other medical treatments, when a pathological fracture is impending or has happened, when a deformity is worsening or has formed, or when there is a suspicion of malignant transformation. The pediatric orthopedist must be aware, therefore, of the particularities of the different bones on which they may be called to intervene, and they should give very careful consideration to their operative strategy, which must be adjusted to the biological and static characteristics of the bone.
Artificial intelligence (AI) has rapidly transformed various aspects of life, and the launch of the chatbot “ChatGPT” by OpenAI in November 2022 has garnered significant attention and user appreciation. ChatGPT utilizes natural language processing based on a ”generative pre-trained transfer” (GPT) model, specifically the transformer architecture, to generate human-like responses to a wide range of questions and topics. Equipped with approximately 57 billion words and 175 billion parameters from online data, ChatGPT has potential applications in medicine and orthopedics. One of its key strengths is its personalized, easy-to-understand, and adaptive response, which allows it to learn continuously through user interaction. This article discusses how AI, especially ChatGPT, presents numerous opportunities in orthopedics, ranging from preoperative planning and surgical techniques to patient education and medical support. Although ChatGPT’s user-friendly responses and adaptive capabilities are laudable, its limitations, including biased responses and ethical concerns, necessitate its cautious and responsible use. Surgeons and healthcare providers should leverage the strengths of the ChatGPT while recognizing its current limitations and verifying critical information through independent research and expert opinions. As AI technology continues to evolve, ChatGPT may become a valuable tool in orthopedic education and patient care, leading to improved outcomes and efficiency in healthcare delivery. The integration of AI into orthopedics offers substantial benefits but requires careful consideration and continuous improvement.
We classify all contact structures with contact surgery number one on the Brieskorn sphere Sigma(2,3,11) with both orientations. We conclude that there exist infinitely many non-isotopic contact structures on each of the above manifolds which cannot be obtained by a single rational contact surgery from the standard tight contact 3-sphere. We further prove similar results for some lens spaces: We classify all contact structures with contact surgery number one on lens spaces of the form L(4m+3,4). Along the way, we present an algorithm and a formula for computing the Euler class of a contact structure from a general rational contact surgery description and classify which rational surgeries along Legendrian unknots are tight and which ones are overtwisted.
Jung-Chun Chen, Shang-Wen Tsai, Cheng-Fong Chen
et al.
Salmonella infection may present in different clinical forms, which usually cause acute gastroenteritis and enteric fever. However, it can also lead to bacteremia, an asymptomatic carrier state, and focal infections in various tissues, including bones. There are very few cases reported in the literature about Salmonella osteomyelitis and even mimicking bone metastasis. Hereby, we report a case of a 55-year-old male presenting with severe pain on the medial side of the right knee for 10 days. Magnetic resonance imaging revealed an ill-defined lobulated-shaped mass in the epiphysis of the right femur, with a hyperintense signal on T2-weighted images. Surgery was performed immediately due to the patient’s severe pain. The pus culture yielded Salmonella Group B. To the best of our knowledge, this is the first report of osteomyelitis of the distal femur caused by Salmonella in an adult with a colon cancer history.
Lateral ankle sprain (LAS) is considered “an acute traumatic injury to the lateral ligament complex of the ankle joint as a result of excessive inversion of the rear foot or a combined plantar flexion and adduction of the foot”. Chronic ankle instability (CAI) is characterized by a history of one significant LAS, subsequent recurrent sprains, episodes of the ankle giving way, or self-reported deficits in ankle function for >1 year following the initial sprain. If untreated, instability may lead to cartilage deterioration and end in degenerative ankle disease. The objective of this review is to provide recent scientific evidence on CAI. Through this article, we have tried to put some light upon a problem that causes significant morbidity to the patient by compilation of the available evidence-based concepts. The need for this article is as there is the absence of a generalized treatment algorithm, the presence of various treatment modalities, the presence of two schools of opinion regarding treatment, and the absence of comprehensive text. Years of research have identified numerous impairments associated with CAI such as decreases in range of motion, strength, postural control, and altered movement patterns during functional activities when compared to individuals with no LAS history. As a result, an impairment-based rehabilitation model was developed to treat the common impairments associated with CAI. The impairment-based rehabilitation model has been shown to be an effective rehabilitation strategy at improving both clinical and patient-oriented outcomes in patients with CAI. We have reviewed the current literature regarding diagnosis, imaging, conservative methods, surgical approaches, and rehabilitation protocols.
Richard F. Ittenbach, J. William Gaynor, Jenny M. Dorich
et al.
Abstract The purpose of this study was to establish the technical merit, feasibility, and generalizability of a new measure of understanding of informed consent for use with clinical research participants. A total of 109 teens/young adults at a large, pediatric medical center completed the consenting process of a hypothetical biobanking study. Data were analyzed using a combination of classical and modern theory analytic methods to produce a final set of 19 items referred to as the uConsent scale. A requirement of the scale was that each item mapped directly onto one or more of the Basic Elements of Informed Consent from the 2018 Final Rule. Descriptive statistics were computed for each item as well as the scale as a whole. Partial credit (Rasch) logistic modeling was then used to generate difficulty/endorsability estimates for each item. The final, 19‐item uConsent scale was derived using inferential methods to yield a set of items that ranged across difficulty levels (−3.02 to 3.10 logits) with a range of point‐measure correlations (0.12 to 0.50), within‐range item‐ and model‐fit statistics, varying item types mapped to both Bloom's Taxonomy of Learning and required regulatory components of the 2018 Final Rule. Median coverage rate for the uConsent scale was 95% for the 25 randomly selected studies from ClinicalTrials.gov. The uConsent scale may be used as an effective measure of informed consent when measuring and documenting participant understanding in clinical research studies today.
Therapeutics. Pharmacology, Public aspects of medicine
Purpose: To investigate the value of antero-posterior and lateral radiographs in predicting clubfoot relapse after treatment with the Ponseti method. Methods: This was a retrospective review of 104 children (157 feet) younger than 3 months of age with idiopathic clubfoot treated using the Ponseti method at our institution between January 2007 and December 2014. All patients underwent Achilles tenotomy and were divided into two groups according to the need for further surgery to correct the deformity: relapsed group (24 patients; 36 feet) and non-relapsed group (80 patients; 121 feet). All antero-posterior and lateral foot radiographs were performed less than 3 months after Achilles tenotomy. The talo-calcaneal (TC-AP) and talus-first metatarsal (TM-AP) angles were measured in the antero-posterior view, while the tibio-calcaneal (TIC-L), talus-first metatarsal (TM-L), and talo-calcaneal (TC-L) angles were measured in the lateral view. The multi-factor logistic regression model of the stepwise selection method was used to predict the relapse of clubfoot deformity from the potential predictive values. Results: The mean age at initial plain radiography examination was 99.45 ± 21.54 days. Differences in TC-AP, TM-AP, TC-L, and TIC-L between the two groups were statistically significant. However, only TM-AP and TIC-L were included in the “ risk of relapse ” formula using the multi-factor logistic stepwise selection method. Conclusion: Early antero-posterior and lateral radiographs in children younger than 3 months of age at initial Ponseti treatment have positive predictive value for relapse. Reduced TM-AP angle and increased TIC-L were associated with an increased risk of relapse. Level of evidence: level III.
We discuss a metric description of the divergence of a (projectively) Anosov flow in dimension 3, in terms of its associated growth rates and give metric and contact geometric characterizations of when a projectively Anosov flow is Anosov. Then, we study the symmetries that the existence of an invariant volume form yields on the geometry of an Anosov flow, from various viewpoints of the theory of contact hyperbolas, Reeb dynamics and Liouville geometry, and give characterizations of when an Anosov flow is volume preserving in terms of those theories. We finally use our study to show that the bi-contact surgery operations of Salmoiraghi can be applied in an arbitrary small neighborhood of a periodic orbit of any Anosov flow. In particular, we conclude that the Goodman surgery of Anosov flows can be performed using a bi-contact surgery of Salmoiraghi.