In orthopedics, bone fixation imposes the use of implants in almost all cases. Over time, the materials used for the implant have evolved from inert materials to those that mimic the morphology of the bone. Therefore, bioabsorbable, biocompatible, and bioactive materials have emerged. Our study aimed to review the main types of implant materials used in orthopedics and present their advantages and drawbacks. We have searched for the pros and cons of the various types of material in the literature from over the last twenty years. The studied data show that consecrated metal alloys, still widely used, can be successfully replaced by new types of polymers. The data from the literature show that, by manipulating their composition, the polymeric compounds can simulate the structure of the different layers of human bone, while preserving its mechanical characteristics. In addition, manipulation of the polymer composition can provide the initiation of desired cellular responses. Among the implanting materials, polyurethane is distinguished as the most versatile polymeric material for use both as orthopedic implants and as material for biomechanical testing of various bone reduction and fixation techniques.

Objective: Reactive oxygen species (ROS) are involved in the endothelial-mediated disorders within atherosclerosis. Considering that an oxidant/antioxidant imbalance might be a key factor in the damaging ROS-mediated effects, the present study intends to determine the influence of a high-fat diet, associated with essential amino acids-valine and leucine, upon the experimental animals, through evaluation of plasmatic level of some antioxidant enzymes. Material and Methods: The study was conducted on 32 male Wistar rats, which were fed with cholesterol, valine and leucine, for 60 days. The animals were divided into four groups, according to the received diet: the first group-standard diet; the second group-cholesterol (C); the third group-cholesterol and valine (C + V); the fourth group-cholesterol and leucine (C + L). Evaluations of the oxidative status, through plasma levels of the antioxidant enzymes: superoxide dismutase (SOD) and glutathione peroxidise (GPx), were made for the four mentioned groups of animals, at the beginning of the study (R0), after one (R1) and two months (R2). Results: The average values of SOD and GPx in group of animals fed exclusively with cholesterol (C) were significantly higher compared to the third group where cholesterol was supplemented with valine (C + V) or fourth group fed with cholesterol and leucine (C + L) (p < 0.001), after one month as well at the end of the experiment (two months). There were no significant differences in the levels of SOD and GPx between group III and group IV (p < 0.05) at the end of the experiment. Conclusion: Our results showed that valine and leucine decreased the serum levels of SOD and GPx and therefore they were useful antioxidants, * Corresponding author. E. Cojocaru et al. 2314 which could improve the endothelial dysfunctions associated with atherosclerosis. Moreover, analysis of the oxidative status in the context of atherosclerotic mediated endothelial damage suggests that deviation from normal to alter endothelial status may be conditioned by an oxidants/antioxidants imbalance.

Hemophilia A is a hereditary coagulopathy caused by the deficiency of the coagulation factor VIII, whose main complication consists in disabling arthropathy. The most often affected joint is the one of the knee, due to which this article aims at presenting, on one hand, the role of continuous substitutive prophylactic treatment in preventing the onset of this complication and, on the other hand, the current view of orthopedic surgery in managing the above-mentioned complication. The continuous prophylactic treatment represents the best therapeutic conduct in preventing the onset of hemophilic arthropathy, yet this aspect is limited by two important factors: inappropriate medical support, dependence on the social and economic level of every country and inappropriate adherence of the patient to this thorough treatment, which represents a challenge for a life with no bleeding. Under the circumstances imposed by an insufficient substitutive treatment or by a deficient adherence of the patient to this, recurrent hemarthrosis shall lead to cartilage destruction and synovial hypertrophy (synovitis), which will impose, in time, total endoprosthesis in order to re-establish the motor function and to improve the life quality of the hemophilic patient. The surgery of the hemophilic patient is associated with an increased risk of hemorrhage and infection and it is practiced only with substitutive hematologic support. The key to the best results is the existence of a multidisciplinary experienced team, including an orthopedist, hematologist, physical therapist.

Thrombophilia, also called hypercoagulability or prothrombotic condition, usually reflects a certain imbalance that occurs either in the coagulation cascade or in the anticoagulation/fibrinolytic system. A similar imbalance may be induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Thrombotic complications are associated with multiorgan failure and increased mortality. In this context, activation of coagulation and thrombocytopenia appeared as prognostic markers in COVID-19. Our work provides a structured and updated analysis of inherited thrombophilia and its involvement in COVID-19, emphasizing the importance of diagnosing and initiating thromboprophylaxis. Since the state of hypercoagulation is directly correlated with COVID-19, we consider that studies on the genetic profiles of proteins involved in thrombophilia in patients who have had COVID-19 and thrombotic events are of great importance, both in treating and in preventing deaths due to COVID-19.

Haemophilia is an inherited disease that requires a different approach in order to evaluate, monitor and treat patients. Despite the great advances in therapeutic agents that have emerged, reports on the impact of monitoring outcomes on treatment decisions are rarely presented. Haemophilia A and haemophilia B are inherited bleeding disorders caused by deficiencies in blood clotting factor proteins. A systematic review was performed to identify literature reports on the current practices in haemophilic patients undergoing orthopedic surgery. The best therapy for haemophilic patients consists in performing primary prophylaxis to prevent joint bleeding and other complications. Besides the primary prophylaxis, thromboprophylaxis is used to prevent venous thrombosis in patients with hemophilia who undergo surgical orthopedic procedures. Further research is needed to better manage the pharmacologic approaches in haemophilic patients undergoing orthopedic surgery. Although patients with haemophilia present low risk for thromboembolic complications, such events have been reported in surgical procedures. The recommendations in patients with haemophilia are considerably variable in the current guidelines and clinical practice. The best therapy for haemophilic patients consists in performing primary prophylaxis to prevent joint bleeding and other complications.