Browsing by Author "Sousa, João Paulo"
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- Amentadione from the alga Cystoseira usneoides as a novel osteoarthritis trotective agent in an ex vivo co-culture OA ModelPublication . Araujo, Nuna C. P.; Viegas, Carla; Zubía, Eva; Magalhães, Joana; Ramos, Acácio; Carvalho, Maria M.; Cruz, Henrique; Sousa, João Paulo; Blanco, Francisco J.; Vermeer, Cees; Simes, DinaOsteoarthritis (OA) remains a prevalent chronic disease without effective prevention and treatment. Amentadione (YP), a meroditerpenoid purified from the alga Cystoseira usneoides, has demonstrated anti-inflammatory activity. Here, we investigated the YP anti-osteoarthritic potential, by using a novel OA preclinical drug development pipeline designed to evaluate the anti-inflammatory and anti-mineralizing activities of potential OA-protective compounds. The workflow was based on in vitro primary cell cultures followed by human cartilage explants assays and a new OA co-culture model, combining cartilage explants with synoviocytes under interleukin-1β (IL-1β) or hydroxyapatite (HAP) stimulation. A combination of gene expression analysis and measurement of inflammatory mediators showed that the proposed model mimicked early disease stages, while YP counteracted inflammatory responses by downregulation of COX-2 and IL-6, improved cartilage homeostasis by downregulation of MMP3 and the chondrocytes hypertrophic differentiation factors Col10 and Runx2. Importantly, YP downregulated NF-κB gene expression and decreased phosphorylated IkBα/total IkBα ratio in chondrocytes. These results indicate the co-culture as a relevant pre-clinical OA model, and strongly suggest YP as a cartilage protective factor by inhibiting inflammatory, mineralizing, catabolic and differentiation processes during OA development, through inhibition of NF-κB signaling pathways, with high therapeutic potential.
- Anterior femoral cut in total knee arthroplasty: a classification proposalPublication . Medeiros, Filipe; Duarte, António; Correia, Bruno; Carvalho, Maria; Vide, João; Fontes, Ana Paula; Sousa, João PauloBackground: The cut of the anterior femur (CAF) sets the rotation of the femoral component, which could affect patellar tracking, and influence the clinical results on total knee arthroplasty (TKA). The aim of this study was to suggest a classification for anterior femoral cut in TKA. Methods: Images of anterior femoral cuts were aggregated in different shapes and defined a classification. Onehundred femoral image’s cuts were analysed by 5 orthopaedic surgeons, which classified them twice. To analyse inter and intra-observer agreement, the Fleiss Kappa test was used. Results: The study proposes the following CAF classification, type 1 (one peak) and type 2 (two peaks); subtypes 1 (a) a central base peak, 1 (b) a lateral base peak, 2 (a) two peaks where the smallest is in the lower half, and 2 (b) two peaks where the smallest is in the upper half. In our study, type 2 (a) was the most common type (54.5%), followed by type 1 (b). The analysis showed good intra- and inter-observer agreements (mean K of 0.774 and 0.627, respectively). The intra and inter-observer concordance was statistically significant in all the analyses. Conclusions: The CAF classification system for TKA is considered a reproducible classification. To our knowledge, there is no study describing a shape’s classification of this cut. A slight rotation of the femoral cutting guide could change the axial rotation and positioning of the femoral component. An undesirable cut could lead to different patellofemoral offset and could consequently cause anterior pain and instability.
- Benefits of tranexamic acid in total knee arthroplasty: a classification and regression tree analysis in function of instrumentation, BMI, and genderPublication . Pereira, Eduardo; Carvalho, Maria Miguel; Oliveira, Tiago; Sacramento, Telmo; Cruz, Henrique; Viegas, Rui; Fontes, Ana Paula; Marreiros, Ana; Sousa, João PauloTranexamic acid (TXA) is an antifibrinolytic drug that reduces blood loss in patients that undergo Total knee arthroplasty (TKA). Few studies compare its effect on conventional instrumentation (CI) versus patient-specific instrumentation (PSI). The main objective of this study was to understand analytically how TXA usage in both instrumentations influenced blood loss in TKA differently and see if the differences seen could be explained by the patient’s body mass index (BMI) and gender. This nonrandomized retrospective study sample consisted of 688 TKA procedures performed on patients who had symptomatic arthrosis resistant to conservative treatment. Descriptive analysis was used to evaluate blood loss using hemoglobin (Hb) mean values and mean variation (%). The Classification and Regression Tree (CRT) method was applied to understand how the independent variables affected the dependent variable. Comparing patients submitted to the same instrumentation, where some received TXA and others did not, patients that received TXA had lower blood loss. Comparing patients who underwent TKA with different instrumentations and without the use of TXA, it was found that patients who underwent TKA with PSI had lower blood loss than those who underwent TKA with CI. However, when these same instruments were compared again, but associated with the use of TXA, the opposite was true with patients undergoing TKA with PSI showing greater blood loss than patients undergoing TKA with CI. TXA usage in TKA is significantly beneficial in minimizing blood loss and regardless of instrumentation. When using TXA, the lowest blood loss was obtained in patients with higher BMI and submitted to TKA with CI. This is most likely explained by the synergistic antifibrotic effect of TXA with adipokines, such as plasminogen activator inhibitor-1 (PAI-1), found in the femoral bone marrow which is perforated using CI. If, however, TXA wasn’t used, the lowest blood loss was obtained in patients submitted to TKA with PS
- Blood management in total knee arthroplasty: an exploratory study regarding the use of drain and tranexamic acid in two types of instrumentationPublication . Dias, Pedro Alexandre; Caldeira-Dantas, Sofia; Carvalho, Maria Miguel; Marreiros, Ana; de Almeida Fontes, Ana Paula; Sousa, João PauloBackground: This study investigates how presence or absence of drain or tranexamic acid (TXA) in 2 different types of instrumentation with invasion/sparing femoral canal affects hemoglobin drop after total knee arthroplasty (TKA). Methods: This was a retrospective observational study that included 736 individuals divided in five groups, regarding conventional instrumentation (CI) or patient specific instrumentation (PSI), presence or absence of drain and TXA. Mean percentage of hemoglobin drop after the first postoperative day was compared for each group. Results: Patients submitted to CI using drain and no TXA revealed the highest value (21,3%±9,1; p<0,001). Groups who received TXA and drain was not used, presented the lowest blood loss. Moreover, with the introduction of TXA PSI lost its advantage over CI. Conclusions: TKA using CI, without drain and with TXA administration showed better results, reducing mean percentage of hemoglobin drop after surgery.
- Characterization of the knee joint phenotype in the Portuguese populationPublication . Seica, Emanuel Cortesao de; Armada, Lucas; Marreiros, Ana; de Almeida Fontes, Ana Paula; Carvalho, Maria Miguel; Sousa, João PauloBackground: Neutral constitutional alignment and neutral joint line obliquity has been the standard alignment strategy for total knee arthroplasty. This one-for-all measure may negatively impact gait pattern and knee biomechanics. Novel alignment strategies surged, considering the variability in phenotypes found across the literature, as different populations may present different phenotype distributions. The Portuguese population has a distinct genetic origin, with no phenotype distribution data. Our objective was to characterise the population’s knee morphology, searching and analysing adjacent joint osteoarthrosis, and calculating the pre-disease coronal alignment. Methods: A retrospective cohort study was conducted. Full-length X-rays performed between 2016-2023 were analysed. Five alignment parameters were measured (LDFA, MPTA, JLCA, TJLA, HKA), and two parameters were calculated (aHKA, JLO). Knees were classified according to the CPAK classification. Results: For the arthritic cohort, CPAK-I (23%) II (20%) were most common, aHKA increases as KL increases (r=0.8352; p<0.001). For the healthy, Type-II (42%) and Type-I (15%) were most common. For paediatric, Type-II (43%) and Type-V (21%) were most common. CPAK Types-VII/VIII/IX were rare. Differences between genders for healthy and arthritic cohorts were statistically significant. The arthritic had higher prevalence of adjacent joint osteoarthritis. Conclusions: The Portuguese population presents a similar knee phenotype comparing with other populations, some differences have been found regarding the Asian continent. The most common phenotype was a neutral alignment if either healthy or paediatric, or a varus alignment if knee OA. Coronal alignment may not have a major impact in the prevalence of ankle and hip osteoarthritis; however, higher prevalence is observed in patients with knee OA.
- The role of the femoral anterior offset index (AOI) on the degree of flexion in total knee arthroplasty (TKA)Publication . Rosa, João Maia; Vide, João; Carvalho, Maria Miguel; Duarte, António; Cruz, Henrique; Fontes, Ana Paula; Sousa, João PauloBackground: Anterior projection of the femoral condyles is often disregarded as an issue in knee arthroplasty. Overstuffing the patellofemoral joint may limit knee flexion and be a source of patellofemoral complications, thus having an impact in satisfaction rates after total knee arthroplasty (TKA). Our hypothesis is that excessive anterior projection of the femoral condyles as a negative effect in flexion range after TKA, introducing a new concept, the anterior offset index (AOI). Methods: From a group of 99 consecutive patients who underwent TKA using patient specific instrumentation (PSI), we selected the patients with good pre-operative flexion range (above 90º) and a 6-minute walk test (6 MWT) ≥ 0 meters, evaluating the correlation between the AOI and the flexion range. A total of 23 patients were included in the study. Results: A moderate and positive correlation (r=0.488; p=0.018) between AOI and flexion range was found. Conclusions: Our results seem to indicate that the AOI influences postoperative flexion in TKA, in patients with a good pre-operative flexion and good functional outcome. AOI is an important concept to retain when optimizing knee flexion and minimizing patellofemoral complications. However, more studies need to be done in order to clarify the role of all the factors influencing post op flexion after TKA.