Phenolic Composition, Antiradical, Antimicrobial, and Anti-Inflammatory Activities of Propolis Extracts from North East Spain.

Antioxidant-related parameters and anti-inflammatory and antimicrobial activities against Listeria monocytogenes were assessed in eight North East Spain poplar propolis samples. Propolis extracts (PEs) were obtained using 70% ethanol (PEE) and methanol (PME). Yield and total phenol compounds were higher in PEE. Phenolic acids were analyzed by a high-performance liquid chromatograph-diode array detector. Caffeic and ferulic acids were quantified in all PEE and PME. All samples contained p-coumaric acid (quantified in 6 PEE and in 3 PME). Ascorbic acid was detected in all propolis, but mainly quantified in PME (≤0.37 mg/g PE). Biological properties were tested on PEE. As for antiradical activities, trolox equivalent antioxidant capacity (TEAC) [against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)•+], ranged between 578 and 4620 µmol trolox/g, 2,2-diphenyl-1-picrylhydrazyl (DPPH) (against DPPH free radical), between 0.049 and 0.094 mg/mL, antioxidant activity against hydroxyl (•OH) radical (AOA), between 0.04 and 11.01 mmol uric acid/g, and oxygen radical absorbance capacity (ORAC) against peroxyl (ROO•) radical between 122 and 3282 µmol trolox/g. Results of TEAC, AOA, and ORAC were significantly correlated. IC50 anti-inflammatory activity ranged from 1.08 to 6.19 mg/mL. Propolis showed higher inhibitory activity against L. monocytogenes CECT934 and L. monocytogenes CP101 by agar well diffusion (P < .05) (10.5 and 10.2 mm, respectively) than against L. monocytogenes CP102 (7.0 mm). Data of this research show that North East Spain propolis may be of interest for pharmaceutical and food industry use.

Desmoplastic Fibroblastoma of the Ankle: A Case Report of a Rare Localization and a Literature Review.

Introduction: Desmoplastic fibroblastoma is a rare, slow-growing benign soft tissue tumor. It has a wide anatomical distribution and mainly affects adult males. Fourteen percent of cases occur in the ankle or foot. Case Report: In this study, we report a rare location of desmoplastic fibroblastoma on the ankle of a 76-year-old female, discovered as a slowly growing mass. Discussion: Desmoplastic fibroblastoma is an anatomical and clinical entity. It appears macroscopically as a pseudocartilaginous structure and histologically as a stellate or spindle-shaped fibroblastic proliferation in a collagenous stroma. Conclusion: Desmoplastic fibroblastoma has anatomical specificities and should still be clearly distinguished from certain malignant tumors.

Mitochondrial Role on Cellular Apoptosis, Autophagy, and Senescence during Osteoarthritis Pathogenesis.

Authors have demonstrated that apoptosis activation is a pathway related to cartilage degradation characteristics of the OA process. Autophagy is an adaptive response to protect cells from various environmental changes, and defects in autophagy are linked to cell death. In this sense, decreased autophagy of chondrocytes has been observed in OA articular cartilage. The aim of this work was to study the role of OA mitochondria in apoptosis, autophagy, and senescence, using OA and Normal (N) transmitochondrial cybrids. Results: OA cybrids incubated with menadione showed a higher percentage of late apoptosis and necrosis than N cybrids. Stimulation of cybrids with staurosporine and IL-1ß showed that OA cybrids were more susceptible to undergoing apoptosis than N cybrids. An analysis of the antioxidant response using menadione on gene expression revealed a lower expression of nuclear factor erythroid 2-like 2 and superoxide dismutase 2 in OA than N cybrids. Activation of microtubule-associated protein 1A/1B-light chain 3 was reduced in OA compared to N cybrids. However, the percentage of senescent cells was higher in OA than N cybrids. Conclusion: This work suggests that mitochondria from OA patients could be involved in the apoptosis, autophagy, and senescence of chondrocytes described in OA cartilage.

Amalophyllonmiraculum (Gesneriaceae), an exceptionally small lithophilous new species from the western Andean slopes of Ecuador.

Recent exploratory field expeditions to the western slopes of the Ecuadorian Andes resulted in the discovery of a new species of Amalophyllon (Gesneriaceae). Amalophyllonmiraculum J.L.Clark, sp. nov. is described from two localities in the Centinela region in the Santo Domingo de los Tsáchilas province. The new species is differentiated from congeners by the pendent habit, basal rosette of leaves, leaf blades with deeply serrate margins, and miniature size. Based on IUCN guidelines, a preliminary conservation status is assigned as Critically Endangered (CR).

ResumenRecientes expediciones exploratorias de campo a las laderas occidentales de los Andes ecuatorianos dieron como resultado el descubrimiento de una nueva especie de Amalophyllon (Gesneriaceae). Amalophyllonmiraculum J.L.Clark, sp. nov. se describe de dos localidades de la región de Centinela en la provincia de Santo Domingo de los Tsáchilas. La nueva especie se diferencia de otros congéneres por el hábito colgante, la roseta basal de las hojas, las láminas foliares con márgenes profundamente aserrados y su tamaño en miniatura. Según las directrices de la UICN, se le asigna el estado de conservación preliminar de En Peligro Crítico (CR).

Persistent ischiorectal fistula secondary to rectal extrusion of posterior vaginal mesh: Case report.

INTRODUCTION AND HYPOTHESIS: Vaginal mesh has been used for years to try to improve the results of pelvic organ prolapse surgery, but current evidence does not confirm this improvement and instead describes serious and frequent adverse events. CLINICAL CASE: 64-year-old patient with rectal extrusion of posterior vaginal mesh placed 8 years earlier, and persistent left ischiorectal fistula refractory to surgery. She required 5 surgeries, carried out jointly between gynecology and general surgery, to solve, firstly, the bilateral perianal abscess secondary to extrusion of the posterior vaginal mesh into the rectum and then the persistent left ischiorectal fistula, despite the removal of the material prosthetic. Finally, the fistula was solved by injection of platelet-rich plasma. CONCLUSIONS: Vaginal mesh complications often need a multidisciplinary approach, and treatment may require multiple approaches and more than one surgical procedure. In the case of a persistent fistula refractory to surgery, after removing the mesh, non-invasive regenerative therapies that promote vascular growth and tissue regeneration could be considered such as platelet-rich plasma.

Cell identity dynamics and insight into insulin secretagogues when employing stem cell-derived islets for disease modeling.

Stem cell-derived islets (SC-islets) are not only an unlimited source for cell-based therapy of type 1 diabetes but have also emerged as an attractive material for modeling diabetes and conducting screening for treatment options. Prior to SC-islets becoming the established standard for disease modeling and drug development, it is essential to understand their response to various nutrient sources in vitro. This study demonstrates an enhanced efficiency of pancreatic endocrine cell differentiation through the incorporation of WNT signaling inhibition following the definitive endoderm stage. We have identified a tri-hormonal cell population within SC-islets, which undergoes reduction concurrent with the emergence of elevated numbers of glucagon-positive cells during extended in vitro culture. Over a 6-week period of in vitro culture, the SC-islets consistently demonstrated robust insulin secretion in response to glucose stimulation. Moreover, they manifested diverse reactivity patterns when exposed to distinct nutrient sources and exhibited deviant glycolytic metabolic characteristics in comparison to human primary islets. Although the SC-islets demonstrated an aberrant glucose metabolism trafficking, the evaluation of a potential antidiabetic drug, pyruvate kinase agonist known as TEPP46, significantly improved in vitro insulin secretion of SC-islets. Overall, this study provided cell identity dynamics investigation of SC-islets during prolonged culturing in vitro, and insights into insulin secretagogues. Associated advantages and limitations were discussed when employing SC-islets for disease modeling.

Time-dependent reduction in oxidative capacity among cultured myotubes from spinal cord injured individuals.

BACKGROUND: Skeletal muscle adapts in reaction to contractile activity to efficiently utilize energy substrates, primarily glucose and free fatty acids (FA). Inactivity leads to atrophy and a change in energy utilization in individuals with spinal cord injury (SCI). The present study aimed to characterize possible inactivity-related differences in the energy metabolism between skeletal muscle cells cultured from satellite cells isolated 1- and 12-months post-SCI. METHODS: To characterize inactivity-related disturbances in spinal cord injury, we studied skeletal muscle cells isolated from SCI subjects. Cell cultures were established from biopsy samples from musculus vastus lateralis from subjects with SCI 1 and 12 months after the injury. The myoblasts were proliferated and differentiated into myotubes before fatty acid and glucose metabolism were assessed and gene and protein expressions were measured. RESULTS: The results showed that glucose uptake was increased, while oleic acid oxidation was reduced at 12 months compared to 1 month. mRNA expressions of PPARGC1α, the master regulator of mitochondrial biogenesis, and MYH2, a determinant of muscle fiber type, were significantly reduced at 12 months. Proteomic analysis showed reduced expression of several mitochondrial proteins. CONCLUSION: In conclusion, skeletal muscle cells isolated from immobilized subjects 12 months compared to 1 month after SCI showed reduced fatty acid metabolism and reduced expression of mitochondrial proteins, indicating an increased loss of oxidative capacity with time after injury.

Los trastornos de la personalidad ¿realidad o ficción? El sombrío futuro de su diagnóstico / Personality disorders: reality or fiction? The bleak future of your diagnosis

El diagnóstico categorial de los trastornos de la personalidad (TTPP) ha sido criticado por diversas razones, entras las que se encuentran el solapamiento de síntomas entre distintos trastornos, su elevada comorbilidad o el carácter dicotómico de su diagnóstico. Estas críticas han llevado al desarrollo de un planteamiento dimensional en las últimas versiones de los sistemas de clasificación, DSM-5/DSM-5-TR y CIE-11, considerando dos aspectos: el funcionamiento de la personalidad y una serie de rasgos patológicos. A pesar de la cuantiosa literatura publicada desde principio de este siglo sobre esta propuesta dimensional, no está claro, a día de hoy, que tenga alguna utilidad clínica. La vaga, abstracta y poco operativizable exposición de lo que constituye el funcionamiento de la personalidad y la compleja y forzada designación de rasgos mayores y menores (facetas) en el DSM-5/DSM-5-TR o sólo mayores y opcionales en la CIE-11, complican el diagnóstico dimensional de los TTPP. En este trabajo se discuten todas estas cuestiones en un intento de aportar algo de luz para un futuro menos sombrío que el actual panorama de los TTPP.(AU)

The categorical diagnosis of personality disorders (PDs) has been criticized forvarious reasons, among which are overlapping of symptoms between differentdisorders, their high comorbidity, and the dichotomous nature of their diagnosis.These criticisms have led to the development of a dimensional approach in thelatest versions of the classification systems, DSM-5/DSM-5-TR and ICD-11,considering two substantial aspects for its new diagnosis: personality functioning,and a series of pathological features. Despite the large amount of literature thathas been published since the beginning of this century on this dimensionalproposal, it is not clear, to date, that this approach enhances clinical utility. Thevague, abstract, and inoperative exposition of what constitutes personalityfunctioning and the complex and forced designation of major and minor traits(facets) in the DSM-5/DSM-5-TR, and only major and optional traits in the ICD-11,complicate, in an unusual way, the dimensional diagnosis of PDs. This paperdiscusses all of these issues in an attempt to shed some light on the potentially darkfuture of the current PDs panorama.(AU)

Management of fixed flexion contracture in primary total knee arthroplasty: recent systematic review.

INTRODUCTION: This study aimed to systematically review the literature and identify the surgical management strategy for fixed flexion contracture in primary total knee arthroplasty (TKA) surgery, pre-, intra-, and post-operatively. Secondary endpoints were etiologies and factors favoring flexion contracture. MATERIALS AND METHODS: Searches were carried out in November 2023 in several databases (Pubmed, Scopus, Cochrane, and Google Scholar) using the following keywords: "flexion contracture AND TKA", "fixed flexion deformity AND TKA", "posterior capsular release AND TKA", "posterior capsulotomy in TKA", "distal femoral resection AND TKA". Study quality was assessed using the STROBE checklist and the Downs and Black score. Data concerning factors or strategies leading to the development or prevention of flexion contracture after TKA were extracted from the text, figures, and tables of the included references. The effect of each predictive factor on flexion contracture after TKA was recorded. RESULTS: Thirty-one studies were identified to meet the inclusion and exclusion criteria. These studies described a variety of preoperative and intraoperative factors that contribute to the development or correction of postoperative flexion contracture. The only clearly identified predictor of postoperative flexion contracture was preoperative flexion contracture. Intraoperative steps described to correct flexion contracture were: soft-tissue balancing (in posterior and medial compartments), distal femoral resection, flexion of the femoral component, and posterior condylar resection. However, no study has investigated these factors in a global model. DISCUSSION: This review identified various pre-, intra-, and post-operative factors predictive of post-operative flexion contracture. In practice, these factors are likely to interact, and it is therefore crucial to further investigate them in a comprehensive model to develop an algorithm for the management of flexion contracture. LEVEL OF EVIDENCE: IV.

Fully angularly resolved 3D microrheology with optical tweezers.

Microrheology with optical tweezers (MOT) is an all-optical technique that allows the user to investigate a materials' viscoelastic properties at microscopic scales, and is particularly useful for those materials that feature complex microstructures, such as biological samples. MOT is increasingly being employed alongside 3D imaging systems and particle tracking methods to generate maps showing not only how properties may vary between different points in a sample but also how at a single point the viscoelastic properties may vary with direction. However, due to the diffraction limited shape of focussed beams, optical traps are inherently anisotropic in 3D. This can result in a significant overestimation of the fluids' viscosity in certain directions. As such, the rheological properties can only be accurately probed along directions parallel or perpendicular to the axis of trap beam propagation. In this work, a new analytical method is demonstrated to overcome this potential artefact. This is achieved by performing principal component analysis on 3D MOT data to characterise the trap, and then identify the frequency range over which trap anisotropy influences the data. This approach is initially applied to simulated data for a Newtonian fluid where the trap anisotropy induced maximum error in viscosity is reduced from ~ 150% to less than 6%. The effectiveness of the method is corroborated by experimental MOT measurements performed with water and gelatine solutions, thus confirming that the microrheology of a fluid can be extracted reliably across a wide frequency range and in any arbitrary direction. This work opens the door to fully spatially and angularly resolved 3D mapping of the rheological properties of soft materials over a broad frequency range.

Unraveling Molecular Recognition of Glycan Ligands by Siglec-9 via NMR Spectroscopy and Molecular Dynamics Modeling.

Human sialic-acid-binding immunoglobulin-like lectin-9 (Siglec-9) is a glycoimmune checkpoint receptor expressed on several immune cells. Binding of Siglec-9 to sialic acid containing glycans (sialoglycans) is well documented to modulate its functions as an inhibitory receptor. Here, we first assigned the amino acid backbone of the Siglec-9 V-set domain (Siglec-9d1), using well-established triple resonance three-dimensional nuclear magnetic resonance (NMR) methods. Then, we combined solution NMR and molecular dynamic simulation methods to decipher the molecular details of the interaction of Siglec-9 with the natural ligands α2,3 and α2,6 sialyl lactosamines (SLN), sialyl Lewis X (sLeX), and 6-O sulfated sLeX and with two synthetically modified sialoglycans that bind with high affinity. As expected, Neu5Ac is accommodated between the F and G ß-strands at the canonical sialic acid binding site. Addition of a heteroaromatic scaffold 9N-5-(2-methylthiazol-4-yl)thiophene sulfonamide (MTTS) at the C9 position of Neu5Ac generates new interactions with the hydrophobic residues located at the G-G' loop and the N-terminal region of Siglec-9. Similarly, the addition of the aromatic substituent (5-N-(1-benzhydryl-1H-1,2,3-triazol-4-yl)methyl (BTC)) at the C5 position of Neu5Ac stabilizes the conformation of the long and flexible B'-C loop present in Siglec-9. These results expose the underlying mechanism responsible for the enhanced affinity and specificity for Siglec-9 for these two modified sialoglycans and sheds light on the rational design of the next generation of modified sialoglycans targeting Siglec-9.

Hollow viscus perforation in blunt abdominal trauma: A 14-year experience from a trauma center.

BACKGROUND: Isolated perforations of hollow viscus (HV) represent less than 1% of injuries in blunt abdominal trauma (BAT). When they do present, they are generally due to high-impact mechanisms in the segments of the intestine that are fixed. The aim of this study is to determine the incidence of major HV injuries in BAT at the "Dr. Domingo Luciani" General Hospital (HDL), and address the literature gap regarding updated HV perforations following BAT, especially in low-income settings. METHODS: A retrospective review was conducted on the medical records of patients admitted to our trauma center with a diagnosis of complicated BAT with HV perforation over 14 years. RESULTS AND DISCUSSION: Seven hundred sixty-one patients were admitted under the diagnosis of BAT. Of them, 36.79% underwent emergency surgical resolution, and 6.04% had HV perforation as an operative finding. Almost half (44.44%) of these cases presented as a single isolated injury, while the remaining were associated with other intra-abdominal organ injuries. The most common lesions were Grade II-III jejunum and Grade I transverse colon, affecting an equal proportion of patients at 13.33%. In recent years, an increased incidence of HV injuries secondary to BAT has been observed. Despite this, in many cases, the diagnosis is delayed, so even in the presence of negative diagnostic studies, the surgical approach based on the trauma mechanism, hemodynamic status, and systematic reevaluation of the polytraumatized patient should prevail.

Epstein-Barr virus-positive mucocutaneous ulcer in a patient with ulcerative colitis: a recently described entity to take into account.

Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a new entity recently included in the classification of B-cell lymphoproliferative disorders associated with Epstein-Barr virus (EBV). It is related to immunosuppression and it usually appears in the oropharynx or the skin, being the colon an uncommon location. We present the case of a 31-year-old man with ulcerative proctitis being treated with azathioprine (AZA) and adalimumab (ADA), who was admitted to the hospital due to suspicion of a moderate-severe flare of ulcerative proctitis. Microbiological stool analyses were negative, with a positive fecal calprotectin test (2700 mg/kg). Rectoscopy showed severe endoscopic activity, taking multiple biopsies. Intravenous steroids were started at a dose of 60 mg/day. He presented a favorable clinical and analytical evolution, being discharged from the hospital. The histological results were received at gastroenterology consultation, being compatible with EBVMCU. AZA and ADA were withdrawn, whereas descending steroid regimen and oral and topical mesalazine were continued, being the clinical response adequate.

Pump-Less, Recirculating Organ-on-Chip (rOoC) Platform to Model the Metabolic Crosstalk between Islets and Liver.

Type 2 diabetes mellitus (T2DM), obesity, and metabolic dysfunction-associated steatotic liver disease (MASLD) are epidemiologically correlated disorders with a worldwide growing prevalence. While the mechanisms leading to the onset and development of these conditions are not fully understood, predictive tissue representations for studying the coordinated interactions between central organs that regulate energy metabolism, particularly the liver and pancreatic islets, are needed. Here, a dual pump-less recirculating organ-on-chip platform that combines human pluripotent stem cell (sc)-derived sc-liver and sc-islet organoids is presented. The platform reproduces key aspects of the metabolic cross-talk between both organs, including glucose levels and selected hormones, and supports the viability and functionality of both sc-islet and sc-liver organoids while preserving a reduced release of pro-inflammatory cytokines. In a model of metabolic disruption in response to treatment with high lipids and fructose, sc-liver organoids exhibit hallmarks of steatosis and insulin resistance, while sc-islets produce pro-inflammatory cytokines on-chip. Finally, the platform reproduces known effects of anti-diabetic drugs on-chip. Taken together, the platform provides a basis for functional studies of obesity, T2DM, and MASLD on-chip, as well as for testing potential therapeutic interventions.

Interplay between Cultured Human Osteoblastic and Skeletal Muscle Cells: Effects of Conditioned Media on Glucose and Fatty Acid Metabolism.

The interplay between skeletal muscle and bone is primarily mechanical; however, biochemical crosstalk by secreted mediators has recently gained increased attention. The aim of this study was to investigate metabolic effects of conditioned medium from osteoblasts (OB-CM) on myotubes and vice versa. Human skeletal muscle cells incubated with OB-CM showed increased glucose uptake and oxidation, and mRNA expression of the glucose transporter (GLUT) 1, while fatty acid uptake and oxidation, and mRNA expression of the fatty acid transporter CD36 were decreased. This was supported by proteomic analysis, where expression of proteins involved in glucose uptake, glycolytic pathways, and the TCA cycle were enhanced, and expression of several proteins involved in fatty acid metabolism were reduced. Similar effects on energy metabolism were observed in human bone marrow stromal cells differentiated to osteoblastic cells incubated with conditioned medium from myotubes (SKM-CM), with increased glucose uptake and reduced oleic acid uptake. Proteomic analyses of the two conditioned media revealed many common proteins. Thus, our data may indicate a shift in fuel preference from fatty acid to glucose metabolism in both cell types, induced by conditioned media from the opposite cell type, possibly indicating a more general pattern in communication between these tissues.

Modelling the effects of climate and land-cover changes on the potential distribution and landscape connectivity of three earth snakes (Genus Conopsis, Günther 1858) in central Mexico.

Anthropogenic land use and climate change are the greatest threats to biodiversity, especially for many globally endangered reptile species. Earth snakes (Conopsis spp.) are a poorly studied group endemic to Mexico. They have limited dispersal abilities and specialized niches, making them particularly vulnerable to anthropogenic threats. Species distribution models (SDMs) were used to assess how future climate and land-cover change scenarios might influence the distribution and habitat connectivity of three earth snakes: Conopsis biserialis (Taylor and Smith), C. lineata (Kennicott), and C. nasus (Günther). Two climate models, CNRM-CM5 (CN) and MPI-ESM-LR (MP) (Representative Concentration Pathway 85), were explored with ENMeval Maxent modelling. Important SDM environmental variables and environmental niche overlap between species were also examined. We found that C. biserialis and C. lineata were restricted by maximum temperatures whereas C. nasus was restricted by minimum ones and was more tolerant to arid vegetation. C. biserialis and C. lineata were primarily distributed in the valleys and mountains of the highlands of the TMBV, while C. nasus was mainly distributed in the Altiplano Sur (Zacatecano-Potosino). C. lineata had the smallest potential distribution and suffered the greatest contraction in the future whereas C. nasus was the least affected species in future scenarios. The Sierra de las Cruces and the Sierra Chichinautzin were identified as very important areas for connectivity. Our results suggest that C. lineata may be the most vulnerable of the three species to anthropogenic and climate changes whereas C. nasus seems to be less affected by global warming than the other species.

Temporal and spatial variability in population traits of an intertidal fucoid reveals local-scale climatic refugia.

Global change is imposing significant losses in the functional traits of marine organisms. Although areas of climatic refugia ameliorate local conditions and help them to persist, the extent to which mesoscale effects contribute for intraregional variability on population traits and conservation is uncertain. Here we assess patterns of conservation status of Fucus guiryi, the main intertidal habitat-forming seaweed in the Strait of Gibraltar (southern Spain and northern Morocco). We investigated the demography, reproductive phenology, and morphology at northern and southern side populations. Population traits were compared seasonally within populations from each side, and at spatial scale in early summer 2019. In the last decade three populations became extinct; two marginal populations had dispersed individuals with a narrower fertility season and miniaturized individuals below 3 cm; and five populations showed variable density and cover with more than 20% of reproductive individuals over the seasons. Highest density, cover, morphology, and reproductive potential was detected at one population from each side, suggesting local-scale climatic refugia in upwelling areas located inside marine protected areas. Southern recruits were more warm-tolerant but grew less at colder conditions than northern ones, revealing a mesoscale heterogeneity in thermal affinities. This study evidenced functional losses and distinct reproductive strategies experienced by F. guiryi at peripheral locations and urges to prioritize its conservation and restoration at contemporary climatic refugia.

Development of three-dimensional primary human myospheres as culture model of skeletal muscle cells for metabolic studies.

Introduction: Skeletal muscle is a major contributor to whole-body energy homeostasis and the utilization of fatty acids and glucose. At present, 2D cell models have been the most used cellular models to study skeletal muscle energy metabolism. However, the transferability of the results to in vivo might be limited. This project aimed to develop and characterize a skeletal muscle 3D cell model (myospheres) as an easy and low-cost tool to study molecular mechanisms of energy metabolism. Methods and results: We demonstrated that human primary myoblasts form myospheres without external matrix support and carry structural and molecular characteristics of mature skeletal muscle after 10 days of differentiation. We found significant metabolic differences between the 2D myotubes model and myospheres. In particular, myospheres showed increased lipid oxidative metabolism than the 2D myotubes model, which oxidized relatively more glucose and accumulated more oleic acid. Discussion and conclusion: These analyses demonstrate model differences that can have an impact and should be taken into consideration for studying energy metabolism and metabolic disorders in skeletal muscle.

Preoperative flexion contracture does not affect outcome in total knee arthroplasty: A case-control study of 2,634 TKAs.

BACKGROUND: One issue in total knee arthroplasty (TKA) is management of preoperative flexion contracture, which may be associated with poor functional outcome. AIM: The aim of this study was to compare functional results in TKA with or without preoperative flexion contracture, treated according to a standardized algorithm of tissue release and bone cut. PATIENTS AND METHOD: A single-center retrospective case-control study was performed on prospectively collected data for the period 1987-2016. Patients with >10̊ flexion contracture were assigned to the "contracture" group and associated to a selected control group at a ratio of 1:4. Clinical analysis used pre and post-operative International Knee Society (IKS) scores. The significance threshold was set at p<0.05. RESULTS: Eight hundred and forty-nine cases and 3,304 controls were included, comprising a total of 2,838 male and 1,315 female participants. Mean preoperative extension deficit was 13̊±6̊ in the contracture group and 1̊±2̊ in controls. Preoperative IKS total and functional scores were significantly poorer in the contracture group (38±18 and 54±20) than in controls (52±16 and 59±19) (p<0.001). Postoperatively, the two groups did not significantly differ in IKS functional score (77±22 vs. 79±21, p=0.143). There were differences in IKS knee score (87±12 vs. 88±13, p=0.006) and maximal flexion (114̊±14̊ vs. 119̊±13̊, p<0.0001) that were statistically, but not clinically, significant. DISCUSSION: A systematic standardized algorithm for surgical treatment of flexion contracture during primary total knee arthroplasty provided clinical outcomes similar to those of patients without preoperative flexion contracture. LEVEL OF EVIDENCE: III; case-control study.