<p>Intraoperativna kontaminacija autokalema tokom rekonstrukcije prednjeg ukr&scaron;tenog ligamenta je i dalje tema koja je predmet stalne debate među ortpedskim hirurzima, a koja se preteţno odnosi na potrebu i način njenog tretmana. Ona nastaje kao posledica naseljavanja uzročnika kontaminacije iz vazduha, sa koţe i sluznica kako pacijenata tako i osoblja, kao i preko nesterilisanih ili nedovoljno sterilisanih instrumenata. Patogeni koji je izazivaju su identični uzročnicima koji izazivaju septični arthritis, pa se smatra jednim od faktora rizika za njegov nastanak. Septični arthritis predstavlja najče&scaron;ću komplikaciju u artroskopskoj hirurgiji uop&scaron;te, a njegove posledice mogu bitno uticati na funkcionalni i mentalni status pacijenata. Zbog toga se smatra da je tretman intraoperativne kontaminacije autokalema tokom rekonstrukcije prednjeg ukr&scaron;tenog ligamenta kolena mandatoran. Najče&scaron;će primenjivani agensi u tretmanu intraoperativne kontaminacije alokalema predstavljaju različite vrste antiseptičnih i antibiotskih solucija. I pored toga &scaron;to intraoperativna irigacija fiziolo&scaron;kim rastvorom predstavlja jednu od najče&scaron;če primenjivanih procedura tokom hirur&scaron;kih operacija, u savremenoj literaturi je objavljen mali broj radova na temu primene ove procedure u tretmanu intraoperativne kontamninacije. Cilj ove studije je bio da pokaţe da se dekontaminacija autoklema tokom rekonstrukcije prednjeg ukr&scaron;tenog ligamenta kolena moţe uspe&scaron;no tretirati intraoperativnom mehaničkom irigacijom čistim fiziolo&scaron;kim rastvorom, kao i da odredi koja je količina fiziolo&scaron;kog rastvora dovoljna da izvr&scaron;i potpunu dekontaminaciju autokalema. Jedan od ciljeva se odnosio na utvrđivanje uticaja faktora okruţenja na pojavu intraoperativne kontaminacije. Studija se sastojala iz dva dela- eksperimentalnog i kliničkog. Eksperimentalni deo studije je bio sproveden na Odeljenju za kliničku bakteriologiju Centra za mikrobiologiju Instituta za javno zdravlje Vojvodine i sastojao se iz pravljenja eksperimentalnog modela koji je imao za cilj da u in vitro uslovima obezbedi iste ili pribliţno iste uslove kao i operacionoj sali. On se sastojao od pedeset ispreparisanih i sterilisanih svinjskih tetiva dubokih pregibača prstiju koje su po svojim dimenzijama pribliţno odgovarale humanom prednjem ukr&scaron;tenom ligamentu kolena. Tetive su potom bile kontaminirane unapred određenom koncetracijom najče&scaron;ćeg uzročnika kontaminacije, a to je koagulaza negativan stafilokok ( ATCC 12228 Staphylococcus epidermidis). One su se potom mehanički ispirale sa 500 ml, 1000 ml, i 1500 ml fiziolo&scaron;kog rastvora, a nakon svakog ispiranja uzimao se bris. Brisevi su nakon toga bili zasejavani na krvni agar, a nakon 24h inkubacije su očitavane vrednosti brojanjem kolonija uzročnika. Rezultati eksperimentalnog dela pokazuju da je količina od 1500 ml fiziolo&scaron;kog rastvora dovoljna da izazove potpunu dekontaminaciju tetive. Rezultati eksperimentalnog dela su potom bili primenjivani u kliničkom delu studije koji je obuhvatao 200 ispitanika starosne dobi između 15-50 godina i koje je je bilo sprovedeno na Klinici za ortopedsku hirurgiju i traumatologiju Kliničkog centra Vojvodine. Kontrolnu grupu su činili onih 100 pacijenata kod kojih je mehaničko intraoperativno ispiranje autokalema neposredno pred njegovu implantaciju vr&scaron;eno pomoću 500 ml fiziolo&scaron;kog rastvora, a ispitivanu grupu su činili drugih sto pacijenata kod kojih je isto to ispiranje izvr&scaron;eno sa 1500 ml fiziolo&scaron;kog rastvora. Rezultati kliničkog dela studije jasno ukazuju da je količina od 1500 ml fiziolo&scaron;kog rastvora kojim se vr&scaron;i intraoperativna mehanička irigacija dovoljna da izvr&scaron;i potpunu dekonaminaciju autokalema kao i da stepen kontaminacije autokalema raste sa povećanjem vremena koje kalem provodi na vazduhu tokom obrade, &scaron;to je u direktnoj vezi sa vremenskim trajanjem operacije i vrstom kalema koji se koristi za rekonstrukciju. Rezultati pokazuju da je rizik za nastanak kontaminacije autokalema u direktnoj vezi sa faktorima okruţenja, odnosno da se porastom broja ljudi u operacionoj sali, kao i redosledom operativnih procedura u toku jednog operativnog dana u smislu da operacije koje počinju kasnije na operativnom programu, povećava i procenat kontaminacije. Intraoperativna mehanička irigacija kontaminiranog autokalema se pokazala kao metoda koja se uspe&scaron;no moţe koristiti u intaoperativnoj dekontaminaciji autokalema tokom rekonstrukcije prednje ukr&scaron;tene veze kolena. Rezultati ove studije se mogu se primeniti i na druge asetne hirurgije i mogu posluţiti i daljim kliničkim istraţivanjima.</p> / <p>Intraoperative contamination of autograft during anterior cruciate ligament reconstruction still remains a topic for debate among orthopaedic surgeons mainly concerning the need and the way of its treatment. Graft contamination arises after pathogen settlement from the surrounding air, from skin and mucoses of patient and staff, as well as not enough sterilized instruments. Pathogens found in graft contamination are the same ones who are causes of septic arthritis, which is the most common complication in arthroscopic surgery in general. Consequences of septic arthritis usually leave a huge impact on patient&rsquo;s mental and physical status. In modern surgery, it is mandatory to prevent potential auto-graft contamination by irrigation (during anterior cruciate ligament reconstruction in knee). Most commonly used agents for intraoperative auto-graft irrigation are variety of antiseptic and antibiotic solutions. Even though intraoperative irrigation with saline solution presents one of the most commonly used procedures during different surgical interventions in general, little is said in literature about its usage in auto-graft contamination. The aim of this study was to show that decontamination of auto-graft during anterior cruciate ligament reconstruction of the knee can be successfully done by mechanical irrigation with saline (0,9%) solution and also to define a precise quantity of saline for complete decontamination. Furthermore, effects of different factors in surroundings were inspected. The study consisted of two parts: experimental and clinical. Experimental part was conducted at the Department for clinical bacteriology, at Microbiology Centre at the Institute for public health of Vojvodina. It consisted in making the experimental model with in vitro conditions similar to or as the same as in the operating theatre. Experimental model was made of 50 preparated and sterilized pig tendons of deep finger flexors, which are similar dimensions as human anterior cruciate ligament of the knee. Then, the tendons were contaminated with previously defined concentration of most common cause of contamination which is coagulase negative staphylococcus (ATCC 12228 Staphylococcus epidermidis). Contaminated tendons were mechanicaly irrigated with 500ml, 1000ml and 1500ml saline solution. After each irrigation a swab was taken and put in blood agar to grow. Following 24h of incubation, bacterial colonies were counted. Results of experimental model show that 1500ml of saline solution is required for decontamination of tendon. Results of experimental model were used in clinical part of the study which was conducted at the Clinic for orthopaedic surgery and traumatology in Clinical Centre of Vojvodina. It comprised of 200 patients, who were 15-50 years old. Patients were divided in two equal groups: tested and control group. In control group mechanical irrigation of auto-graft was done prior to its implementation with 500ml saline solution, while in tested group 1500ml of saline was used for irrigation. Results of clinical part of the study show that intraoperative irrigation with 1500ml of saline solution is enough for complete decontamination of auto-graft. Furthermore, degree of auto-graft contamination rises with prolonged exposure time on surrounding air, with incrised number of people in the operating theatre and also with number and sequence of operations during the day. Intraoperative mechanical irrigation proved to be a sufficient method that can be used in intraoperative autograft decontamination during anterior cruciate ligament reconstruction. The results of this study can be applied to other aspects of the surgery and could be used and further clinical<br />studies.</p>

<p>Uvod: magnetno rezonantni imidžing (MR) je u &scaron;irokoj uporebi u dijagnostici patolo&scaron;kih poremećaja ekstremiteta. Postoji interes da se redukuje vreme trajanja snimanja tokom pregleda kako bi se povećao komfor pacijenata i redukovali problemi koji su u vezi sa klaustrofobijom i artefaktima koji nastaju pri pomeranju pacijenta tokom dugih snimanja. Trodimenzionalne (3D) izovoksel sekvence pokazale su značajne mogućnosti u redukciji vremena snimanja MR pregledom zgloba kolena bez smanjenja kvaliteta dijagnostičkih mogućnosti. Cilj: uporediti dijagnostičke mogućnosti rutinskog, 2D MR protokola, na 3.0 Tesla MR aparatu, sa 3D True fast imaging, TrueFISP, izovoksel sekvencom u detekciji hondralnih o&scaron;tećenja, ruptura prednjeg ukr&scaron;tenog ligamenta (LCA), ruptura meniskusa i abnormalnosti subhondralne kosti, u korelaciji sa artroskopijom, kao referentnim standardom. Materijal i metode: Studija je odobrena od institucionalnog etičkog odbora. Pacijenti su informisani o studiji i potpisali pristanak za uče&scaron;će u istraživanju. 76 zgloba kolena kod 76 pacijenata (34 ženskog pola; prosečne starosti 36 godina) uključeno je u prospektivnu studiju, snimljeno je standardnim 2D MR protokolom snimanja i 3D TrueFISP sekvencom u sagitalnoj ravni. Svim pacijentima je urađena artroskopija u periodu od maksimum 30 dana nakon snimanja. Dva radiologa, nezavisno jedan od drugog, su evaluirala dobijene snimke. Preciznost u detekciji hondralnih o&scaron;tećenja, ruptura LCA i meniskusa, i abnormalnosti subhondralne kostne srži je određena podudarno&scaron;ću radiolo&scaron;kih i artroskopskih nalaza kao i proverom podudaranja ove dve metode snimanja. Rezultati: prosečna senzitivnost i specifičnost 3DTrueFISP sekvence je bila 75%, 94% respektivno, u dijagnostici o&scaron;tećenja hrskavice, 97%, 97% u detekciji ruptura LCA, 65%, 89% u postavljanju dijagnoze ruptura meniskusa, a dobra podudarnost radiolo&scaron;kih nalaza je dobijena u interpretaciji o&scaron;tećenja subhondralne kosti. Standardnim 2D MR protokolom prosečna senzitivnost i specifičnost je bila 70%, 93%, respektivno, u postavljanju dijagnoze hondralnih o&scaron;tećenja, 94% i 100% u postavljanju dijagnoze rupture LCA, 65%, 88% u detekciji ruptura meniskusa. Zaključak: dijagnostičke mogućnosti upotrebom 3DTrueFISP sekvence su uporedive sa standardnim, 2D, MR protokolom u snimanju zgloba kolena.</p> / <p>Introduction: Magnetic resonance imaging (MR) is widely used to assess internal derangements of the extremities. There is an interest in decreasing examination times to improve patient comfort and reduce the problems related to claustrophobia and motion artifacts, which occur more commonly with long examinations. The three-dimensional (3D) isovoxel true FISP sequence facilitates a noticeable reduction in acquisition time for MR imaging of the knee without reducing diagnostic performance. Objective: To compare the diagnostic performance of conventional, 2D, MR protocol, at 3.0 Tesla MR, with 3D water-excitation true fast imaging with steady-state precession, TrueFISP, an isotropic resolution sequence for detecting articular cartilage defects, anterior crucial ligament tears, meniscal tears and subhondral bone changes of the knee joint, with arthroscopy as reference standard. Materials and methods: The study was institutional review board approved. Written informed consent was obtained from all patients. 76 knees of 76 patients (34 females; mean age 36 years) were prospectively examined by using a conventional 2D MR protocol and sagittal 3D TrueFISP sequence. All patients underwent arthroscopy within a maximum period of 30 days after imaging. Two blinded readers evaluated the MR images. Accuracy for detection of cartilage defects, anterior cruciate ligament and meniscal tears, and subchondral bone abnormalities interobserver agreement, and intermethod agreement were calculated. Results: Overall sensitivity and specificity of 3DTrueFISP sequence were, respectively, 75%, 94% for diagnosis cartilage defects, 97%, 97%, for a diagnosis ACL tears, 65%, 89% for diagnosis of meniscal tears and with good interobserver agreement in interpretation of subhondral bone abnormalities. The standard MR protocol had overall sensitivities and specificities 70%, 93%, respectively, for diagnosis of cartilage defects, 94% and 100% for diagnosis ACL tears and 65%, 88% for diagnosis meniscal tears. Conclusion: The diagnostic perfomance of knee MR imaging performed by using a 3DTrueFISP sequence is comparable to the diagnostic performance of the conventional, 2D, MR protocol.</p>

OBJETIVO: Avaliar o padrão de degeneração histológica do ligamento cruzado posterior (LCP) em pacientes com artrose submetidos à artroplastia total de joelho com prótese com substituição do ligamento cruzado posterior (LCP). A degeneração histológica foi classificada em leve, moderada e grave. Os achados histológicos foram correlacionados com dados clínicos, radiográficos e do transoperatório (presença ou ausência do ligamento cruzado anterior) com a finalidade de aferir se estes parâmetros seriam capazes de predizer o grau de degeneração histológica do LCP em pacientes com gonartrose. MÉTODOS: foram avaliados 89 ligamentos cruzados posterior de 85 pacientes com idade média de 69,79 anos, sendo 69 do sexo feminino, 16 do masculino. O LCP foi corado em hematoxilina-eosina e Tricrômio de Gomori e classificado quanto ao comprometimento histológico em leve, moderado e grave. A degeneração histológica foi correlacionada aos parâmetros idade, artrose radiográfica classificada por Ahlbäck (grau I ao V), eixo radiográfico tíbio-femoral (varo, neutro e valgo), e estado do ligamento cruzado anterior (LCA), presença ou ausência.Os achados histológicos de hipercelularidade, infiltração linfocitária crônica, proliferação vascular; presença de cistos; clones de condrócitos; degenerações colágena, fibrinóide, cartilaginosa ,gordurosa e mucoide foram correlacionados com o grau de degeneração do LCP e ao estado de conservação do LCA. RESULTADO: Não foram identificadas relações entre o grau de degeneração histológica do LCP e faixa etária (abaixo ou acima de 70 anos), sexo, classificação radiográfica de Ahlbäck e presença ou ausência do LCA. Os achados histológicos de degeneração fibrinóide, proliferação vascular e presença de cistos estiveram estatisticamente relacionados à degeneração histológica grave do LCP. CONCLUSÃO: Os parâmetros clínicos e radiográficos não foram capazes de predizer o grau de degeneração histológica do LCP .Os achados histológicos de degeneração fibrinóide, proliferação vascular e presença de cistos caracterizaram a degeneração histológica grave do LCP / OBJECTIVE: Evaluate the histologic degeneration pattern of the posterior cruciate ligament (PCL) in osteoarthrosis patients submitted to total knee replacement with a cruciate substituting prosthesis. The histologic degeneration was classified in mild, moderate and severe. The histologic pattern was related to clinical, per-operatory (presence or absence of anterior cruciate ligament) and radiographic parameters with the aim to settle if these parameters would be reliable to predict the PCL degeneration grade. METHODS: 89 PCLs from 85 patients, 16 men, 69 women, mean age 69, 79 years old. PCL was stained with hematoxylin and eosin and trichromium of Gomori. The PCL histologic degeneration was graded from normal-minimum to severe. The histologic PCL degeneration pattern was related to age, radiographic arthrosis classification (Ahlbäck - grades I to V), knee radiographic axis (varus, neutral, valgus) and to the ACL status (presence or absence).The histologic findings of hipercellularity, chronic lymphocit infiltration, neoangiogenesis, cysts, collagen degeneration (deg), fibrinoid deg, mucoid deg., cartilaginous, deg., fat deg. and condrocyte clones were related to the grade of PCL degeneration and to ACL status. RESULTS: There was no correlation of histologic degeneration to sex or age (above or below 70 years), arthrosis radiographic classification (Ahlbäck) and presence or absence of ACL. The histological findings of fibrinoid degeneration, vascular proliferation and cysts were statistically related to severe histologic LCP degeneration. CONCLUSION: The parameters studied were not capable of predicting the grade of LCP degeneration. The histological findings of fibrinoid degeneration, vascular proliferation and cysts were characteristic of severe PCL histologic degeneration

OBJETIVOS: Avaliar o efeito de sulfato de glicosamina e sulfato de condroitina sobre a nocicepção e o dano da cartilagem articular em um modelo de osteoartrite experimental em ratos. MÉTODOS: Osteoartrite (OA) foi induzida em ratos Wistar machos por transecção do ligamento cruzado anterior (TLCA) do joelho direito. Um grupo falso-operado (SHAM) foi utilizado como controle. Animais OA foram tratados v.o. desde 7 dias antes, até o sacrifício, 70 dias após a TLCA, com sulfato de glicosamina 500 mg/kg (Glu), a combinação sulfato de glicosamina 500 mg/kg e sulfato de condroitina 400 mg/kg (GluChon), ou salina (OANT). Um grupo controle positivo recebeu meloxicam 6 mg/kg s.c. A dor articular foi avaliada pelo teste de incapacitação articular para ratos. Os animais foram sacrificados em diferentes períodos (7,14,28 e 70 dias) após a TLCA. A gravidade das lesões histopatológicas foi graduada nos fêmures após coloração por H&E e azul de toluidina através do escore da OARSI. A quantidade de glicosaminoglicanos (GAGs) extraídos da cartilagem articular dos côndilos femorais foi medida após eletroforese em gel de agarose. O tamanho molecular dos GAGs foi medido após eletroforese em gel de poliacrilamida. A liberação de NO no líquido sinovial foi medida 7 dias após TLCA. RESULTADOS: GluChon reduziu significativamente a dor articular nesse modelo (p<0,01). Glu também reduziu a dor articular, mas não se alcançou significância estatística. Os animais OA apresentaram um aumento significativo dos GAGs na cartilagem articular aos 70 dias após TLCA (77,68±3,38 µg/mg) quando comparados aos animais SHAM (53,46±4,58 µg/mg). O tamanho molecular dos GAGs foi significativamente maior nos animais OA que nos animais SHAM 70 dias após a cirurgia (p<0,01). GluChon preveniu tanto o aumento da quantidade de GAGs (54,42±5,39 µg/mg), quanto de seu tamanho molecular (p<0,05), e estes resultados acompanharam-se de melhora significativa da lesão histopatológica (p<0,05). Os resultados obtidos com Glu foram semelhantes, porém menos evidentes, e não alcançaram significância estatística. Glu aumentou significativamente a quantidade de NO na cavidade articular 7 dias após a TLCA. CONCLUSÕES: GluChon foi antinociceptivo e reduziu significativamente a incapacitação articular. A lesão da cartilagem articular no modelo de TLCA em ratos se acompanha de aumento da concentração e do tamanho molecular dos GAGs, e o tratamento com GluChon previne essas alterações e reduz o dano histopatológico. GluChon foi mais eficaz do que Glu tanto na redução da dor quanto da lesão da cartilagem articular, sugerindo benefício da combinação sobre o uso isolado de sulfato de glicosamina. / OBJECTIVES: Evaluate the antinociceptive and chondroprotective effects of glucosamine sulfate and chondroitin sulfate. METHODS: Male Wistar rats underwent anterior cruciate ligament transection (ACLT) or sham operation of the right knee. Animals were treated p.o. with glucosamine sulfate (Glu) 500 mg/kg, the combination of glucosamine sulfate 500 mg/kg and chondroitin sulfate 400 mg/kg (GluChon), or saline, since 7 days prior to surgery until the sacrifice 70 days after ACLT. A positive control group received meloxicam 6 mg/kg s.c. for antinociceptive evaluation comparisons. Joint pain was evaluated with rat incapacitation test. Animals were sacrificed 7,14,28 or 70 days after ACLT. The severity of histopathologic lesions was evaluated on femoral condyles after hematoxylin-eosin or toluidine blue staining with OARSI grading and staging system. Cartilage extracted glycosaminoglycans (GAGs) concentration was assessed after agarose gel electrophoresis. GAGs\' molecular weight was evaluated after polyacrylamide gel electrophoresis. NO release in synovial fluids was assessed 7 days after ACLT. RESULTS: GluChon reduced joint pain (p<0.01). Glu also reduced joint pain, but results did not reach statistical significance. A significant increase in articular cartilage\'s GAGs concentration was observed in OA animals (77.68±3.38 µg/mg) as compared to sham (53.46±4.58 µg/mg). OA animals also had significantly higher molecular weight GAGs than sham (p<0.01). GluChon prevented both GAG concentration and molecular weight elevations in OA animals, and that was associated with significant less cartilage damage assessed by histopathologic examination (p<0.05). Glu effects were less evident, and did not reach statistical significance. Glu was associated with significant higher concentrations of NO in synovial fluid. CONCLUSIONS: GluChon was antinociceptive on the ACLT model in rats. Articular cartilage damage was associated with increased amounts of GAG with higher molecular weight, and the prevention of these alterations with GluChon treatment was associated with less histopathologic damage. GluChon was more efficient than Glu for both pain and articular cartilage damage reduction, suggesting that combined treatment is better than glucosamine sulfate alone.

O autor estudou as propriedades biomecânicas dos tendões dos músculos tibial anterior e tibial posterior congelados a -20°C e a -86°C extraídos de cadáveres humanos frescos. Foram realizados ensaios mecânicos de tração até a ruptura e determinadas as seguintes propriedades: resistência máxima, coeficiente de rigidez, módulo de elasticidade e alongamento máximo relativo. Os dados obtidos foram comparados aos existentes na literatura relativos ao ligamento cruzado anterior, ligamento da patela e aos tendões dos músculos grácil e semitendíneo / The author studied the mechanical properties of the anterior and posterior tibialis muscle tendons frozen at -20°C and -86°C obtained from fresh-frozen human cadavers. The tendons were submitted to axial traction until failure and the following properties were determined: ultimate load, stiffness, modulus of elasticity and relative strain. Data obtained were compared to those from the literature related to the anterior cruciate ligament, patellar tendon, gracilis and semitendinous tendons

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L'ingénierie tissulaire, qui consiste à remplacer un tissu lésé par un biosubstitut constitué de cellules réparatrices ensemencées dans une matrice de support biodégradable, possède un potentiel prometteur pour la réparation du Ligament Croisé Antérieur (LCA). Or, aucune solution opérationnelle n'a encore été proposée à ce jour, notamment au vu du nombre de domaines scientifiques impliqués. Dans ce travail, nous avons dressé un cahier des charges pour la définition de cette matrice en nous appuyant sur l'état de l'art. Une matrice de support tressée multicouche constituée de fibres de P(LL85/CL15) a été imaginée, puis les outils nécessaires à sa fabrication à l'échelle du laboratoire ont été mis en place. Nous avons ensuite développé des outils numériques spécifiques permettant la modélisation de sa géométrie et de son comportement biomécanique multi-échelles, qui ont été mis à profit afin d?optimiser les caractéristiques de la matrice compte tenu du cahier des charges établi. De plus, des caractérisations biologiques ont montré que la matrice était compatible avec la culture de cellules souches, et était susceptible d?accueillir la formation d'un néo-tissu. Par ailleurs, nous avons mis en place un bioréacteur spécifique permettant d'imposer à la matrice de support des cycles de traction-torsion sous environnement contrôlé. L'utilisation des informations locales issues de la modélisation biomécanique, afin d'interpréter ou d'optimiser les résultats de culture cellulaire sous sollicitations cycliques, constitue une perspective majeure du présent travail. Notre investigation permet en outre de penser qu'un nouveau biosubstitut pour le LCA pourrait prochainement être proposé / Tissue engineering, which consists in replacing an injured tissue with a biodegradable scaffold seeded with cells, has the potential to overcome the limitations associated with current reconstructions strategies of the Anterior Cruciate Ligament (ACL). However, no relevant solution has been proposed yet, especially due to the variety of scientific fields involved in this approach. In the current study, the key requirements for the design of a new scaffold have been listed from the current state of art. A scaffold based on P(LL85/CL15) fibers arranged into a multilayer braided structure has been proposed, and the tools needed to process this scaffold have been developed. Dedicated numerical tools have been proposed in order to predict the morphological and multiscale biomechanical behavior of the scaffold. These simulation tools have enabled to optimize the scaffold geometry in order to match the selected key requirements for ACL tissue engineering. Moreover, preliminary biological assessments have shown that the scaffold was suited for the culture of stem cells and for tissue formation. In addition, a dedicated bioreactor has been developed in order to prescribe tension-torsion cycles within a controlled environment. The use of local information issued from the biomechanical simulations open large perspectives as far as the optimization of culture conditions and the understanding of mechanisms that govern the formation of a ligamentous tissue are concerned. As a conclusion, the present study is likely to enable a new solution for ACL tissue engineering to emerge in the next years

OBJETIVOS: Avaliar o efeito de sulfato de glicosamina e sulfato de condroitina sobre a nocicepção e o dano da cartilagem articular em um modelo de osteoartrite experimental em ratos. MÉTODOS: Osteoartrite (OA) foi induzida em ratos Wistar machos por transecção do ligamento cruzado anterior (TLCA) do joelho direito. Um grupo falso-operado (SHAM) foi utilizado como controle. Animais OA foram tratados v.o. desde 7 dias antes, até o sacrifício, 70 dias após a TLCA, com sulfato de glicosamina 500 mg/kg (Glu), a combinação sulfato de glicosamina 500 mg/kg e sulfato de condroitina 400 mg/kg (GluChon), ou salina (OANT). Um grupo controle positivo recebeu meloxicam 6 mg/kg s.c. A dor articular foi avaliada pelo teste de incapacitação articular para ratos. Os animais foram sacrificados em diferentes períodos (7,14,28 e 70 dias) após a TLCA. A gravidade das lesões histopatológicas foi graduada nos fêmures após coloração por H&E e azul de toluidina através do escore da OARSI. A quantidade de glicosaminoglicanos (GAGs) extraídos da cartilagem articular dos côndilos femorais foi medida após eletroforese em gel de agarose. O tamanho molecular dos GAGs foi medido após eletroforese em gel de poliacrilamida. A liberação de NO no líquido sinovial foi medida 7 dias após TLCA. RESULTADOS: GluChon reduziu significativamente a dor articular nesse modelo (p<0,01). Glu também reduziu a dor articular, mas não se alcançou significância estatística. Os animais OA apresentaram um aumento significativo dos GAGs na cartilagem articular aos 70 dias após TLCA (77,68±3,38 µg/mg) quando comparados aos animais SHAM (53,46±4,58 µg/mg). O tamanho molecular dos GAGs foi significativamente maior nos animais OA que nos animais SHAM 70 dias após a cirurgia (p<0,01). GluChon preveniu tanto o aumento da quantidade de GAGs (54,42±5,39 µg/mg), quanto de seu tamanho molecular (p<0,05), e estes resultados acompanharam-se de melhora significativa da lesão histopatológica (p<0,05). Os resultados obtidos com Glu foram semelhantes, porém menos evidentes, e não alcançaram significância estatística. Glu aumentou significativamente a quantidade de NO na cavidade articular 7 dias após a TLCA. CONCLUSÕES: GluChon foi antinociceptivo e reduziu significativamente a incapacitação articular. A lesão da cartilagem articular no modelo de TLCA em ratos se acompanha de aumento da concentração e do tamanho molecular dos GAGs, e o tratamento com GluChon previne essas alterações e reduz o dano histopatológico. GluChon foi mais eficaz do que Glu tanto na redução da dor quanto da lesão da cartilagem articular, sugerindo benefício da combinação sobre o uso isolado de sulfato de glicosamina. / OBJECTIVES: Evaluate the antinociceptive and chondroprotective effects of glucosamine sulfate and chondroitin sulfate. METHODS: Male Wistar rats underwent anterior cruciate ligament transection (ACLT) or sham operation of the right knee. Animals were treated p.o. with glucosamine sulfate (Glu) 500 mg/kg, the combination of glucosamine sulfate 500 mg/kg and chondroitin sulfate 400 mg/kg (GluChon), or saline, since 7 days prior to surgery until the sacrifice 70 days after ACLT. A positive control group received meloxicam 6 mg/kg s.c. for antinociceptive evaluation comparisons. Joint pain was evaluated with rat incapacitation test. Animals were sacrificed 7,14,28 or 70 days after ACLT. The severity of histopathologic lesions was evaluated on femoral condyles after hematoxylin-eosin or toluidine blue staining with OARSI grading and staging system. Cartilage extracted glycosaminoglycans (GAGs) concentration was assessed after agarose gel electrophoresis. GAGs\' molecular weight was evaluated after polyacrylamide gel electrophoresis. NO release in synovial fluids was assessed 7 days after ACLT. RESULTS: GluChon reduced joint pain (p<0.01). Glu also reduced joint pain, but results did not reach statistical significance. A significant increase in articular cartilage\'s GAGs concentration was observed in OA animals (77.68±3.38 µg/mg) as compared to sham (53.46±4.58 µg/mg). OA animals also had significantly higher molecular weight GAGs than sham (p<0.01). GluChon prevented both GAG concentration and molecular weight elevations in OA animals, and that was associated with significant less cartilage damage assessed by histopathologic examination (p<0.05). Glu effects were less evident, and did not reach statistical significance. Glu was associated with significant higher concentrations of NO in synovial fluid. CONCLUSIONS: GluChon was antinociceptive on the ACLT model in rats. Articular cartilage damage was associated with increased amounts of GAG with higher molecular weight, and the prevention of these alterations with GluChon treatment was associated with less histopathologic damage. GluChon was more efficient than Glu for both pain and articular cartilage damage reduction, suggesting that combined treatment is better than glucosamine sulfate alone.

Despite years of research, females continue to have a higher incidence of non-contact ACL injuries. One of the major findings of this research is that males and females perform certain tasks, such as, cutting, landing, and single-leg squatting, differently. In particular, females tend to move the knee into a more valgus position; a motion putting the ACL at risk for injury. Yet the underlying spinal control mechanisms modulating this motion are unknown. Additionally, the mechanisms regulating the ability to rapidly initiate and produce maximal torque are also unknown. Therefore, the purpose was to: 1) determine if the sexes modulate spinal control differently, 2) examine the contributions of spinal control mechanisms to valgus knee motion, and 3) identify contributions of spinal control to the ability to rapidly produce force. The spinal control variables were the first derivative of the Hoffmann (H)-reflex, the first derivative of extrinsic pre-synaptic inhibition (EPI), the first derivative of intrinsic pre-synaptic inhibition (IPI), recurrent inhibition (RI), and V-waves. To assess the neuromuscular system’s ability to rapidly activate, rate of torque development (RTD) and electromechanical delay (EMD) were measured. Lastly, valgus motion was determined by the frontal plane projection angle (FPPA). The results reveal males and females do modulate spinal control differently; specifically males had an increased RTD, which is the slope of the torque-time curve, and increased RI, which is a post-synaptic regulator of torque output. However, the spinal control mechanisms did not significantly contribute to FPPA at the knee. EMD which is the time lag from muscle activity to torque production was significantly predicted by the spinal control mechanisms. Specifically, EPI, a modulator of afferent inflow from peripheral and descending sources, IPI, a regulator of Ia afferent inflow, and sex significantly contributed to EMD. Lastly, the spinal control mechanisms significantly contributed to RTD. Specifically, IPI, sex, and V-waves, a measure of supraspinal drive, all significantly contributed to RTD. / Graduation date: 2009

Female athletes exhibit three- to six-fold greater incidence of noncontact anterior cruciate ligament (ACL) injury relative to their male counterparts. The increased risk appears to stem from interactions between several risk factors, that can roughly be categorized as anatomic, biomechanical, hormonal, and neuromuscular. Neuromuscular risk factors have recently gained a greater focus, and include differences in the timing and magnitude of activation of lower extremity and trunk musculature. In addition to neuromuscular risk factors, the incidence of ACL injury is not evenly distributed across the menstrual cycle, suggesting that hormonal fluctuations may influence neuromuscular control. Finally, it is known that even well-trained athletes experience decrements in performance and postural control when forced to attend to multiple sensory stimuli, which is common in many sports. PURPOSE: To explore neuromuscular differences in the ways healthy and ACL-injured women respond to a secondary task requiring fine motor control and sustained mental focus (typing task). Our investigation encompassed three broad aims. First, we sought to determine whether ACL-injured individuals demonstrated similar reflex profiles to healthy individuals, as well as to determine whether the ACL-involved limb was similar to its uninvolved counterpart. Our second aim was to determine whether the typing task resulted in attenuated Hoffmann (H) reflex amplitudes, and to investigate whether any observed changes were similar in healthy and ACL-injured groups. Finally, our third broad aim was to utilize more complex H reflex analysis techniques to determine whether differences in spinal excitability existed at different points in the menstrual cycle. METHODS: Thirty nine recreationally active women (20 with prior unilateral noncontact ACL injury: 24.0 ± 4.5 years; 23.8 ± 4.5 kg•m⁻²; 4.1 ± 2.6 years post-injury; 19 with no history of knee injury: 23.8 ± 4.5 years; 23.1 ± 2.3 kg•m⁻²) agreed to participate, and were tested during days 2-5 (follicular phase) of the menstrual cycle. A sub-set of this original group (n=8; 24.0 ± 4.8 years; 22.0 ± 2.1 kg•m⁻²) also agreed to return for a second testing session 24-96 hours after ovulation (early luteal phase), in order to assess H reflex differences across the menstrual cycle. During each testing session, H reflex testing was used to explore spinal-level control mechanisms of the lower extremity musculature under both Rest and Task conditions. In the control group, the dominant limb was tested (CON-D) while in the ACL group, both the uninvolved (ACL-UN) and involved (ACL-INV) limbs were assessed. Differences between groups (Control vs. ACL) and within-groups (ACL-UN vs. ACL-INV) were explored. RESULTS: At rest, H reflex parameters in ACL-INV were generally similar to ACL-UN and to CON-D. However, differences in presynaptic inhibition were apparent in ACL-INV that imply reduced reflex plasticity. During the typing task, both the Control and ACL groups experienced attenuated H reflex parameters. In the sub-set of participants who were tested twice during the menstrual cycle, a significant increase in presynaptic inhibition was observed during the early luteal phase compared to the follicular phase. CONCLUSION: While individuals with prior ACL injury display similar H reflex profiles to healthy individuals, the ACL-involved limb may demonstrate less reflex plasticity in response to environmental changes. This lack of plasticity may potentially increase the risk of re-injury. In addition, an upper extremity task requiring fine motor control and sustained mental focus attenuates the H reflex in both groups. This attenuation has implications for lower-extremity neuromuscular control in dual-task environments. Finally, the increase in presynaptic inhibition observed during the early luteal phase may provide insight into why ACL injuries are not evenly distributed across the menstrual cycle. / Graduation date: 2012