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

<p>Osnovni cilj rekonstrukcije prednjeg ukr&scaron;tenog ligamenta kolena je dobijanje pune stabilnosti kolena u celom obimu pokreta. Bez obzira na razvoj operativne tehnike i rehabilitacije i dalje postoji jedan broj pacijenata koji nije u potpunosti zadovoljan rezultatom rekonstrukcije prednjeg ukr&scaron;tenog ligamenta kolena, te je potrebno izvr&scaron;iti ponovnu operaciju. Smatra se da je najče&scaron;ći uzrok rane ponovne nestabilnosti lo&scaron;a pozicija kalema, tj. pozicija tunela koja nije na anatomskom mestu. Većina hirurga koji se bave ovom problematikom procenjuju poziciju kalema u golenjači na osnovu standardnih radiograma: prednje-zadnje i bočne projekcije, &scaron;to svakako nije dovoljno precizno. U ekonomski&nbsp; razvijenim zemljama poziciju kalema određuju analizirajući snimke kompjuterizovane tomografije (CT) ili magnetne rezonance (MRI). Prvenstveno zbog smanjenja doze zračenja kojoj se izlažu pacijenti prilikom kompjuterizovane tomografije, ali i iz ekonomskih razloga bilo bi korisno razvijanje jednog lako dostupnog, jeftinog ali preciznog i jednostavnog metoda određivanja položaja kalema u golenjači. Osnovni cilj ovog istraživanja bio je da se dokaže značaj pozicije kalema u golenjači i mogućnost svakodnevne kliničke primene novorazvijenog kompjuterskog programa u cilju određivanja prostorne pozicije kalema u golenjači iz samo dva standardna radiograma. Studija je bila eksperimentalno-prospektivnog karaktera. Eksperimentalni deo istraživanja sproveden je na Fakultetu tehničkih nauka (FTN) u Novom Sadu na Departmanu za proizvodno ma&scaron;instvo gde je na osnovu standardnih RTG snimaka (prednje-zadnje i bočne projekcije) razvijen kompjuterski program za određivanje prostornog položaja kalema u golenjači. U cilju verifikacije novorazvijenog programa realizovano je prostorno određivanje položaja kalema u golenjači obradom standardnih RTG snimaka (prednje-zadnje i bočne projekcije) kod 10 pacijenata kod kojih je izvr&scaron;ena primarna rekonstrukcija prednjeg ukr&scaron;tenog ligamenta kolena. Dobijeni rezultati su upoređeni sa položajem kalema na CT snimcima koji su obezbeđeni za sve pacijente. Na taj način je eksperimentalnim putem utvrđena preciznost novorazvijenog softvera u određivanju prostornog položaja kalema u golenjači. Drugi deo istraživanja bilo je prospektivno kliničko ispitivanje koje je sprovedeno na Klinici za ortopedsku hirurgiju i traumatologiju Kliničkog centra Vojvodine u Novom Sadu. Ispitivanu grupu je činilo 120 pacijenata, oba pola, sa prekidom prednjeg ukr&scaron;tenog ligamenta levog ili desnog kolena. Metodom slučajnog izbora pacijenti su podeljeni u četiri grupe od po 30 pacijenata prema veličini sagitalnog ugla (S) bu&scaron;enja kanala u golenjači (S 60&ordm;-69,9&ordm; i S 70&ordm;-80&ordm;) i prema veličini transverzalnog ugla (T) bu&scaron;enja kanala u golenjači (T 60&ordm;-69,9&ordm; i T 70&ordm;-80&ordm;). Grupa I 30 pacijenata (S 60&ordm;-69,9&ordm; i T 60&ordm;-69,9&ordm;), grupa II 30 pacijenata (S 60&ordm;-69,9&ordm; i T 70&ordm;-80&ordm;), grupa III 30 pacijenata (S 70&ordm;-80&ordm; i T 60&ordm;-69,9&ordm;), grupa IV 30 pacijenata (S 70&ordm;-80&ordm; i T 70&ordm;-80&ordm;). Svi pacijenti su godinu dana nakon operacije pro&scaron;li klinička ispitivanja po bodovnim skalama (Tegner bodovna skala, Lysholm bodovna skala i IKDC standard) i artrometrijska merenja. Rezultati dobijeni merenjem položaja kalema u golenjači, kliničkim ispitivanjima i artrometrijskim merenjima poređani su unutar svake grupe posebno, a izvr&scaron;eno je i poređenje dobijenih rezultata između svih grupa. U ispitivanje su uključeni samo oni pacijenti koji su dali potpisani informisani pristanak da učestvuju u ispitivanju nakon detaljnog upoznavanja sa planiranom procedurom. Svaki pacijent je bio informisan o svrsi i načinu sprovođenja istraživanja, kao i o pregledima i merenjima koja će biti vr&scaron;ena. Statističkom analizom rezultata utvrđeno je da veličina gre&scaron;ke prostornog određivanja položaja kalema u golenjači posle rekonstrukcije prednjeg ukr&scaron;tenog ligamenta kolena novorazvijenim kompjuterskim programom nije statistički značajna, a kompjutersko određivanje položaja kalema u golenjači omogućava iste rezultate kao i CT snimci. Sumiranjem zaključaka nakon sveobuhvatne analize dobijenih rezultata istraživanja, može se zaključiti da pozicija kalema u golenjači posle rekonstrukcije prednjeg ukr&scaron;tenog ligamenta kolena utiče na postoperativni funkcionalni rezultat.</p> / <p>The main goal of reconstruction of the anterior cruciate ligament of the knee is to obtain complete knee stability in the full range of movement. Regardless of the development of operational techniques and rehabilitation, there is still a number of patients who are not completely satisfied with the result of reconstruction of the anterior cruciate ligament, and a re-operation is required. It is believed that the most common cause of the instability is the bad position of the graft, i.e. position of the tunnel that is not at the anatomical place insertion. Most surgeons who deal with this problem evaluate the position of the graft in the tibia based on standard radiograms: anterior-posterior and lateral projections, which is not precise enough. In economically developed countries, the position of the graft is determined by analyzing images of computerized tomography (CT) or magnetic resonance (MRI). Primarily due to a decrease in the radiation dose exposed to patients during computerized tomography, but also for economic reasons, it would be useful to develop an easily accessible, inexpensive but precise and simple method for determining the position of the graft in the tibia. The main goal of this examination was to prove the significance of the position of the graft and the possibility of daily clinical use of the newly developed computer program in order to determine in-space position of the graft in only two standard radiograms. The study was experimental-prospective. The experimental part of the research was conducted at the Faculty of Technical Sciences (FTN) in Novi Sad at the Department of Production Engineering, where a computer program for determining in-space position of the graft in the tibia was developed on the basis of standard RTG images (anterior-posterior and lateral projections). In order to verify the newly developed program, in-space determination of the position of the graft in the tibia by processing standard RTG images (anterior-posterior and lateral projections) was performed in 10 patients in which the primary reconstruction of the anterior cruciate ligament was performed. The obtained results were compared with the position of the grafts on CT images provided to all patients. In this way, the accuracy of newly developed software in determining in-space position of the graft in the tibia was determined experimentally. The second part of the study was a prospective clinical trial conducted at the Clinic for Orthopedic Surgery and Traumatology at the Clinical Center of Vojvodina in Novi Sad. The investigated group consisted of 120 patients, both sexes, with a break of the anterior cruciate ligament of the left or right knee. By random selection, patients were divided into four groups of 30 patients according to the size of the sagital angle (S) of the tunnel drilling in the tibia (S 60&ordm;-69,9&ordm; and S 70&ordm;-80&ordm;) and according to the transversal angle (T) of the drill tunnel in the tibia ( T 60&ordm;-69.9&ordm; and T 70&ordm;-80&ordm;). Group I 30 patients (S 60&ordm;-69.9&ordm; and T 60&ordm;-69.9&ordm;), group II 30 patients (S 60&ordm;-69.9&ordm; and T 70&ordm;-80&ordm;), group III 30 patients (S 70&ordm;-80&ordm; and T&ordm;60&ordm; -69.9&ordm;), group IV 30 patients (S 70&ordm;-80&ordm; and T 70&ordm;-80&ordm;). All of the patients underwent clinical trials by scales (Tegner score scale, Lysholm score scale and IKDC standard) and arthrometric measurements one year after surgery. The results obtained by measuring the position of the graft in the tibia, clinical trials and arthrometric measurements were classified separately in each group, and obtained results were compared between all groups. The study included only those patients who gave signed informed consent to participate in the study after being thoroughly informed about planned procedure. Each patient was informed about the purpose and method of conducting the research, as well as the examinations and measurements to be performed. Statistical analysis of the results showed that the size of the error in measuring in-space determination of the position of the graft in tibia after reconstruction of the anterior cruciate ligament of the knee by a newly developed computer program was not statistically significant, and the computer determination of the position of the graft in the tibia provides the same results as the CT images. Summarizing the conclusions after a comprehensive analysis of the obtained results of the study, it can be concluded that the position of the graft in tibia after reconstruction of the anterior cruciate ligament affects the postoperative functional result.</p>

Αναδρομική μελέτη των 13 ασθενών με σηπτική ψευδάρθρωση κάτω πέρατος μηριαίου που αντιμετωπίστηκαν με ευρύ χειρουργικό καθαρισμό και με τη μέθοδο Ilizarov. Κατά την έναρξη της τελικής αντιμετώπισης όλοι οι ασθενείς είχαν σημαντικό περιορισμό της κίνησης της άρθρωσης του γόνατος. Ο μέσος όρος προηγούμενων χειρουργικών επεμβάσεων ήταν τρεις. Ο μέσος όρος οστικού ελλείμματος ήταν 8.3 εκ. Ο μέσος χρόνος εξωτερικής οστεοσύνθεσης ήταν 309.8 ημέρες. Σύμφωνα με τα κριτήρια Paley σε οκτώ ασθενείς είχαμε άριστο οστικό αποτέλεσμα, ενώ το λειτουργικό αποτέλεσμα ήταν σε τρεις περιπτώσεις άριστο, σε τέσσερις καλό. Πώρωση του κατάγματος, εκρίζωση της λοίμωξης και αποκατάσταση της στηρικτικής ικανότητας του σκέλους επιτεύχθηκε σε όλους τους ασθενείς. Η αύξηση του χρόνου εξωτερικής οστεοσύνθεσης παρατηρήθηκε: 1) η οριστική αντιμετώπιση εφαρμόστηκε 6 μήνες μετά από τον αρχικό τραυματισμό. 2) ο ασθενής υποβλήθηκε σε 4 τουλάχιστον προηγούμενες χειρουργικές επεμβάσεις 3) η αρχική αντιμετώπιση συμπεριλάμβανε ανοικτή ανάταξη και εσωτερική οστεοσύνθεση. Με την μέθοδο Ilizarov επιτυγχάνεται πλήρη εκρίζωση της οστικής λοίμωξης, υψηλό ποσοστό πώρωσης και αποκατάσταση της στηρικτικής ικανότητας του σκέλους. Ωστόσο συχνά η δυσκαμψία του γόνατος και η χωλότητα αποτελούν χρόνιο πρόβλημα για αρκετούς ασθενείς. / We retrospectively reviewed 13 patients with infected nonunion of the distal femur, which had been treated by radical surgical debridement and Ilizarov method. All had severely restricted movement of the knee and a mean of 3.1 previous operations. The mean bone defect was 8.3 cm and no patient was able to bear weight. The mean external fixation time was 309.8 days. According to the Paley’s grading system, eight patients had an excellent bone result and seven excellent and good functional results. Bone union, the ability to bear weight fully, and eradication of infection were achieved in all the patients. The external fixation time was increased when the definitive treatment started six months or more after the initial trauma, the patient had been subjected to more than four previous operations and the initial operation had been ORIF. The treatment of infected defect pseudarthrosis of the distal femur using the Ilizarov device is a salvage procedure, as it offers complete eradication of infection, high union rate and ability for full weight bearing. Nevertheless problems such as, impaired knee joint motion and limping bother the patients permanently.

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

The aim of this pilot study was to evaluate the bioactive, surface-coated polycaprolactone-co-lactide scaffolds as bone implants in a tibia critical size defect model. Polycaprolactone-co-lactide scaffolds were coated with collagen type I and chondroitin sulfate and 30 piled up polycaprolactone-co-lactide scaffolds were implanted into a 3 cm sheep tibia critical size defect for 3 or 12 months (n¼5 each). Bone healing was estimated by quantification of bone volume in the defects on computer tomography and microcomputer tomography scans, plain radiographs, biomechanical testing as well as by histological evaluations. New bone formation occurred at the proximal and distal ends of the tibia in both groups. The current pilot study revealed a mean new bone formation of 63% and 172% after 3 and 12 months, respectively. The bioactive, surface coated, highly porous three-dimensional polycaprolactone-co-lactide scaffold stack itself acted as a guide rail for new bone formation along and into the implant. These preliminary data are encouraging for future experiments with a larger group of animals.

Made available in DSpace on 2016-01-26T12:51:52Z (GMT). No. of bitstreams: 1 rogerioleonebuchaim_tese.pdf: 3407631 bytes, checksum: 87786b69303a26860816554562d2cdab (MD5) Previous issue date: 2004-05-17 / The present study was aimed at examining the biocompatibility of anionic collagen matrices, their local bone response following implantation in surgically-created bone defects and also the influence of the collagen fiber orientation in the neoformed bone tissue. Seventy two rats ( Rattus norvegicus albinus ) were used in this experiment. The animals were divided into four experimental groups: Group 1 (control), without implants; Group 2, pericardium medullar implants, 12 hours; Group 3, medullar implants of tendon, 24 hours, with the bigger axes of collagen fibers parallel to the bigger axes of the tibia; and Group 4, medullar implants of tendon, 24 hours, with the bigger axes of collagen fibers perpendicular to the bigger axes of the tibia. After the experimental surgery, the evolution of the repair process was microscopically evaluated in 7, 15 and 30 days post-surgery. The results demonstrated the implanted matrices to be biocompatible and to function as a scaffold inducing the formation of bone, mainly in Group 4. At first, the cellularity follows the arrangement of collagen fibers, obtaining a growing multidirectional arrangement, suggesting that the direction and the orientation are related to the direction and to the magnitude of the stress applied to the bone. / Este estudo apresentou como objetivo, examinar a biocompatibilidade de matrizes de colágeno aniônico, sua resposta óssea local após implantação em defeitos ósseos criados cirurgicamente e a influência da orientação das fibras colágenas no tecido ósseo neoformado. Foram utilizados 72 ratos (Rattus norvegicus albinus) divididos em 4 grupos experimentais de 6 animais cada: Grupo 1 (controle), sem implante; Grupo 2, implante medular pericárdio 12 horas; Grupo 3, implante medularde tendão 24 horas, com o maior eixo de suas fibras colágenas direcionados paralelamente ao maior eixo da tíbia e , Grupo 4, implante medular de tendão 24 horas, com o maior eixo de suas fibras colágenas direcionadas perpendicularmente ao maior eixo da tíbia. A evolução do processo de reparo, após a cirurgia experimental, foi avaliada microscopicamente com 7, 15 e 30 dias pós-operatórios. Os resultados demosntraram que as matrizes implantadas são biocompatíveis e funcionam como uma matriz tridimensional induzindo a formação de osso, maior no grupo 4. a celularidade, inicialmente, acompanha o arranjo das fibras colágenas, adquirindo um arranjo multidirecional crescente, sugerindo que a direção e a orientação estão relacionadas com a direção e a magnitude do stress aplicado sobre o osso.