A lesão do ligamento cruzado anterior (LCA) é incapacitante para vários esportes pela instabilidade e deficiência funcional. O tratamento indicado é a reconstrução cirúrgica do ligamento, no entanto, nem sempre a recuperação funcional após a operação é suficiente para o retorno ao esporte. O objetivo deste estudo foi avaliar o controle postural dinâmico, a força muscular e o parâmetro funcional medido pelo Hop Test de atletas com e sem lesão do LCA. Métodos: Foram incluídos 74 atletas, 60 homens e 14 mulheres, com idades entre 16 e 45 anos, divididos em dois grupos: Grupo-Lesão LCA (GL) com 34 atletas (25,05 anos ± 6,82) e Grupo-Controle (GC) com 40 atletas sem lesão de LCA (27,7 anos ± 8,16). Todos os voluntários realizaram posturografia, dinamometria isocinética e o Hop Test. O GL foi avaliado antes e 12 meses após a reconstrução. O Grupocontrole (GC) foi avaliado num único momento. Resultados: Nas comparações pré e pós-operatórias do GL: a posturografia mostrou maior área de deslocamento no pré-operatório; na dinamometria isocinética, o pico de torque e trabalho total foram maiores no pós-operatório, mas a relação entre músculos flexores e extensores foi menor que a preconizada em ambas as avaliações (pré e pós-operatório); no Hop Test, a distância saltada e a simetria entre os membros foram maiores no pós-operatório. Na comparação com o GC, a posturografia mostrou maior oscilação anteroposterior e menor oscilação mediolateral no GL pré-operatório; na dinamometria isocinética, o pico de torque e trabalho total foram maiores no pré-operatório. No pós-operatório, GL mostrou maior relação entre flexores e extensores que GC. Conclusão: Os atletas submetidos à reconstrução do LCA apresentaram melhor desempenho funcional na avaliação pós-operatória quando comparados com o pré-operatório e com GC. Porém, os parâmetros isocinéticos apresentaram recuperação incompleta / The injury of the anterior cruciate ligament (ACL) is crippling for various sports by instability and functional impairment. The recommended treatment is surgical ligament reconstruction, however, sometimes that functional recovery after operation is not enough to return to the sport. The objective of this study was to evaluate the dynamic postural control, muscle strength, and functional parameter measured by Hop Test of athletes with and without ACL injury. Method: We included 74 athletes, 60 men and 14 women, who are between 16 and 45 years old, divided into two groups: Injury Group (GL) with 34 athletes (25.05 years ± 6.82) and Group Control (GC) with 40 athletes without ACL injury (27.7 years ± 8.16). All volunteers held posturography, isokinetic dynamometry and the Hop Test. The GL was assessed before and 12 months after the reconstruction. The Control Group was evaluated in a single moment. Results: Pre and postoperative comparison of GL: posturography showed greater area of displacement; in isokinetic dynamometry, peak torque and total work were higher in the postoperative period, but the relationship between flexors and extensors muscles was lower than recommended in both evaluation (pre and postoperative); in Hop Test, the distance hopped and the symmetry between the limbs was greater in the postoperative period. In comparison to the GC, posturography showed greater anteroposterior oscillation and lower mediolateral oscillation in preoperative GL; in isokinetic dynamometry, peak torque and total work were higher in GL preoperative. In postoperative period GL showed higher relationship between flexors and extensors than GC. Conclusion: The athletes submitted to ACL reconstruction showed better functional performance in postoperative assessment when surgery was compared to the preoperative period, and to GC. However, isokinetic parameters showed incomplete recovery

O efeito da imobilização no ligamento cruzado anterior, através de atadura gessada por um período de 6 semanas, foi estudado em ratos machos, adultos da raça Wistar. Para esta análise foram desenvolvidos dispositivos que permitiram a fixação do espécime à Máquina de Ensaio Universal e a realização de ensaio mecânico de tração. Através desta metodologia a tração foi aplicada na interlinha articular, somente na junção osso-ligamento-osso. Os dados obtidos foram analisados, quanto à carga máxima, deformação máxima, e energia absorvida pelo ligamento até o momento da ruptura. Nos resultados obtidos não foi observado diferença estatisticamente significativa na resistência do ligamento cruzado anterior, do membro imobilizado em relação ao membro não imobilizado, o que nos indica que provavelmente um período de 6 semanas de imobilização o qual permite pequeno grau de movimento como é o caso da imobilização gessada, não foram suficientes para produzir alterações na resistência ligamentar. / The effects of immobilization through plaster cast for 6 weeks on the mechanical properties of the anterior cruciate ligament (ACL) of Wistar adult mate rats were analysed. Special grips for retaining the specimens during traction tests in a universal test machine were developed. In this way, traction forces could be applied directly to bone-ligament-bone complex. Maximal load, maximal deformation, stiffness and absorbed energy up to the rupture point were considered, compared to the contralateral (normal) ACL. No significant difference could be demonstrated leading us to the conclusion that, at least for the considered lenght of time of immobilization (6 weeks), no important changing in the mechanical properties of the LCA occurred. This contradictory result compared to others in the literature was imputed to the different methodology here employed, where the forces could be applied directly to bone-ligament-bone complex, instead of the femur, anterior cruciate ligament and part of tibia. In addition, the relativily short period by immobilization and the movement permited by the slack immobilization could also be responsabilite for the results.

INTRODUÇÃO: A precisão no posicionamento dos túneis ósseos na reconstrução do ligamento cruzado anterior do joelho (LCA) é considerado um dos fatores fundamentais para o bom resultado dessa cirurgia. A cirurgia ortopédica auxiliada por computador (computer aided orthopedic surgery CAOS) é um avanço tecnológico que tem como um dos principais objetivos exatamente o aumento da precisão. OBJETIVO: comparar o posicionamento do centro dos túneis e a isometria do enxerto obtidos com o uso de um sistema de navegação computadorizada (Orthopilot) e com o uso de guias cirúrgicos convencionais. MÉTODOS: 36 joelhos pareados de cadáveres tiveram o LCA ressecado por artroscopia no Laboratório de Artroscopia do Departamento de Ortopedia e Traumatologia da Faculdade de Medicina da Universidade de São Paulo. Um joelho de cada par foi ramdomizado para o grupo 1 (guias cirúrgicos convencionais) e o outro para o grupo 2 (Orthopilot). Um fio de sutura inelástico foi passado pelo centro dos túneis tibial e femoral confeccionados para a reconstrução do LCA, sem que os túneis fossem finalmente brocados. Todos os joelhos foram então analisados quanto ao posicionamento do centro do túnel tibial (distância do LCP, distância da tubérculo intercondilar medial da tíbia e distância do corno anterior do menisco lateral), do centro do túnel femoral (distância da cortical posterior e angulação coronal na fossa intercondilar do fêmur) e a variação da distância entre os pontos centrais do túnel femoral para o túnel tibial em flexão de 90º e em extensão (isometria). Os dados foram analisados segundo o teste de Wilcoxon para comparação de duas amostras pareadas. RESULTADOS: A variação da distância entre o tunel femoral e tibial em flexão e extensão (isometria) foi maior no grupo 1 convencional, do que no grupo 2 Orthopilot (grupo 1: média 4,2mm com intervalo de 1,1mm a 9,4mm versus grupo 2: média 2,8mm com intervalo de 0,3mm a 6,7mm; p<0,05). Os outros parâmetros analisados não tiveram diferença estatística entre os grupos e demonstraram que todos os túneis dos dois grupos estavam bem posicionados de acordo com os critérios adotados. CONCLUSÕES: O emprego de instrumental cirúrgico navegado pelo sistema Orhtopilot permitiu o posicionamento dos túneis ósseos da reconstrução do LCA de maneira tão precisa quanto os guias cirúrgicos convencionais utilizados. Mais do que isso, proporcionou um posicionamento significativamente mais isométrico nessa série / INTRODUCTION: Precise tunnel location has been considered to be very important to achieve good results in anterior cruciate ligament (ACL) reconstruction surgery. Computer Aided Orthopedic Surgery (CAOS) is a technology improvement whose main objective is to enhance precision. PURPOSE: To compare the accuracy of tunnel placement and graft isometry for ACL reconstruction performed with the use of a computer-assisted navigation system (Orthopilot) and with traditional instruments. METHODS: 36 matched-paired cadaveric knees had their intact ACL removed by arthroscopy at the Arthroscopy Laboratory Orthopedic Department of University of São Paulo Medical School. One knee of each pair was randomized to group 1 (traditional instruments) or group 2 (Orthopilot). An inelastic suture was then passed through the center of where would be the tibial tunnel and then through the center of where would be the femoral tunnel. None of the tunnels were actually drilled. All knees were then dissected and 6 parameters were obtained: The distance from the tibial tunnel center to: 1) the PCL; 2) the lateral meniscus anterior horn; 3) the medial tibial spine. 4) The distance from the femoral tunnel center to the posterior femoral cortex. 5) The femoral tunnel coronal angle. 6) The variation of the distance from the femoral to the tibial tunnels with the knee extended and in 90 degree flexion. The data were submitted to statistical analysis and compared with the Wilcoxon Matched Pairs Test. RESULTS: The variation of the distance from the femoral to the tibial tunnels in flexion and extension was smaller in the Orthopilot group (better isometry): group 1: mean 4.2 mm (1.1-9.4 mm); group 2: mean 2.8 mm (0.3-6.7 mm) p<0,05. All other parameters showed no statistical difference between the groups and all tunnels were considered to be in satisfactory positions. DISCUSSION: There was no difference in tunnel position between the groups. Better isometry was achieved in the Orthopilot group compared to conventional instruments

Introdução: A função principal do ligamento anterolateral (LAL) é a restrição secundária da rotação medial da tíbia, alterando o teste Pivot shift. Os estudos evidenciam uma piora da estabilidade rotacional quando há lesão do LAL associada ao ligamento cruzado anterior (LCA), que é melhorada após a reconstrução combinada desses ligamentos, mas quanto às alterações na função muscular, não há esclarecimento na literatura de como esses indivíduos se comportam. Objetivo: Analisar se há diferença na função muscular flexora e extensora do joelho e abdutora do quadril entre os grupos com indicação para reconstrução combinada do LCA e LAL (grupo LCA+LAL) e reconstrução isolada do LCA (grupo LCA), e secundariamente realizar avaliação clínica e da funcionalidade. Métodos: Avaliação por dinamometria isocinética para o objetivo primário utilizando as velocidades angulares 60º/s para o quadril e 60 e 120º/s para o joelho e para o secundário, uso da escala Lysholm e testes funcionais, como o Single Hop Test e Cross Over Hop Test e avaliação clínica da dor, pela escala visual analógica; translação anterior da tíbia, com o artrômetro (KT-1000) e perimetria do joelho e da coxa (fita métrica). Resultados: Nenhuma diferença foi encontrada quanto a função muscular do quadril e joelho no membro acometido ao se comparar os grupos LCA+LAL e LCA. Entretanto, observou-se um menor trabalho total extensor a 60º/s no membro contralateral ao lesionado observada no grupo LCA+LAL em relação ao grupo LCA e na avaliação da diferença entre os membros houve uma maior diferença entre eles no grupo LCA referente a função extensora do joelho (pico de torque, trabalho total e relação agonista/antagonista) a 60º/s, o que também ocorreu a 120º/s para o trabalho total extensor e relação agonista/antagonista do joelho para esse grupo. Quanto as variáveis secundárias, 68,9% do grupo LCA+LAL referiram dor no joelho e 61,9% no grupo LCA e houve um aumento significativo da translação anterior da tíbia no LCA+LAL em relação ao LCA. Conclusão: Não há diferença entre os grupos LCA+LAL e LCA no que se refere a função muscular do quadril e joelho e funcionalidade. O grupo LCA+LAL apresentou uma maior translação anterior da tíbia em relação ao grupo LCA / Introduction: The main function of the anterolateral ligament (ALL) is the secondary restriction of tibial medial rotation, resulting in a change on the Pivot shift test. Studies show a worse rotational stability when there is an ALL lesion associated with an anterior cruciate ligament (ACL) lesion, which is improved after the combined reconstruction of these ligaments. Regarding the alterations on muscle function, there is no understanding in the literature on how these individuals behave. Purpose: To analyze if there is a difference in the muscle function (knee flexor and extensor and hip abductor) between the groups with indication for combined ACL and ALL reconstruction (ACL+ALL group) and isolated ACL reconstruction (ACL group). Secondarily, to do a clinical and functional evaluation. Methods: Isokinetic dynamometry for the primary objective using 60º/s angular velocities for the hip and 60 and 120º/s for the knee. Secondarily, the use of the Lysholm scale and functional tests, such as Single Hop Test and Cross Over Hop Test and clinical evaluation of pain by visual analogue scale; anterior translation of the tibia, with the arthrometer (KT-1000) and perimetry of the knee and thigh (tape measure). Results: No differences were found regarding hip and knee muscle function in the affected limb when the ACL+ALL and ACL groups were compared. However, there was a lower total extensor work at 60º/s in the limb contralateral to the lesion observed in the ACL+ALL group in relation to the ACL group. Evaluating the difference between the members there was a greater difference between them in the ACL group (peak torque, total work and agonist/antagonist ratio) at 60º/s, which also occurred at 120º/s for total extensor work and knee agonist / antagonist relation for this group. Regarding the secondary variables, 68.9% of the ACL+ALL group reported knee pain and 61.9% in the ACL group, and there was a significant increase in anterior tibial translation in the ACL+ALL group in relation to the ACL group. Conclusion: There is no difference between ACL+ALL and ACL groups regarding hip and knee muscle function and functionality. The ACL+ALL group presented a greater anterior translation of the tibia in relation to the ACL group

Um das Langzeitüberleben eines Kreuzbandtransplantates nach Ersatz des VKB zu gewährleisten muß das Transplantat revaskularisiert werden. Trotz zahlreicher Studien zu diesem Thema gibt es noch immer eine kontroverse Diskussion bezüglich der Revaskularisierung von Kreuzbandtransplantaten. Ziel der vorliegenden Studie war es die endoligamentäre mikrokapilläre Revaskularisierung eines freien Sehnentransplantates mit Hilfe immunhistochemischer Färbetechnik darzustellen und ihren Verlauf über die Zeit zu dokumentieren. Darüber hinaus sollten die im Rahmen des Remodelingprozesses nach vorderem Kreuzbandersatz ablaufenden Ab- und Aufbauprozesse der Extrazellulärmatrix des Transplantates weiter aufgeklärt werden. Bei der Heilung des medialen Kollateralband des Kniegelenkes wurden kontraktile fibroblastische Zellen entdeckt, die eine mögliche Rolle bei der Wiederherstellung der Matrixhomöostase spielen. Nach Entdeckung dieses Zelltyps im intakten vorderen Kreuzbandes wurde gemutmaßt, Myofibroblasten könnten eine entscheidende Rolle bei der Entstehung der Kollagentertiärstruktur spielen. In der vorliegenden Studie sollte aufgeklärt werden, ob Myofibroblasten im intakten ovinen vorderen Kreuzband und seinem freien Sehnentransplantat nach VKB-Ersatz während des Remodelings wieder auftaucht. 36 ausgewachsene Merinoschafe erhielten einen vorderen Kreuzbandersatz mittels ipsilateralem Flexorsehnentransplantat. Nach je 6, 9, 12, 24, 52 und 104 Wochen wurden 6 Tiere getötet und das mittlere Drittel des Kreuzbandtransplantates histologisch aufgearbeitet. Neben konventionellen Färbungen zur Auswertung von Gesamtzellzahl und Crimpstruktur wurden immunhistochemische Färbungen mit anti-v. Willebrandt Factor (Factor VIII) zum Nachweis von Endothelzellen der Gefäßwand und anti-alpha-smooth-muscle Aktin zum Nachweis von Myofibroblasten durchgeführt. In Querschnittpräparaten, je in 3 Zonen (subsynovial, intermediär und zentral) unterteilt, wurden Gefäßanschnitte ausgezählt. In Längsschnittpräparaten wurden Myofibroblasten nachgewiesen. Die Auswertungen wurden mit Hilfe eines digitalen Bildanalysesystems vorgenommen. Die Untersuchungen zur Revaskularisierung zeigten von peripher nach zentral über die Zeit einwachsende Kapillaren. Die größte Dichte an Gefäßanschnitten wurde nach 6 Wochen gefunden, der Gefäßstatus des nativen VKB wurde nach 24 Wochen erreicht. Myofibroblasten konnten sowohl im intakten VKB als auch im Flexorsehnentransplantat vor Implantation nachgewiesen werden. Weiterhin konnten Myofibroblasten erstmalig auch im remodelierenden Bandgewebe bereits nach 6 Wochen innerhalb neu gebildeter Kollagenfasern identifiziert werden. Die vorliegende Studie konnte damit erstmalig die Kinetik der endoligamentären Revaskularisierung auf kapillärer Ebene darstellen. Im vorliegenden Modell war die Revaskularisierung wesentlich früher abgeschlossen als zuvor beschrieben. Myofibroblasten stellen einen regulären Bestandteil sowohl des nativen als auch des remodelierenden VKB dar. Dabei könnten diese Zellen eine wichtige Rolle bei der Wiedererlangung der Gewebehomöostase durch die Ausbildung der Kollagentertiärstruktur spielen. Die Präsenz dieser Zellen während der frühen Remodellingphase läßt weiterhin vermuten, daß alpha smooth muscle Actin exprimierende Zellen in der frühsten Phase der Bildung von Kollagenfibrillen mitbeteiligt sind. / After replacement of the anterior cruciate ligament with a free tendon autograft, the substitute initially is avascular and without a synovial surface. To ensure long-term survival, the graft must become revascularised. Despite numerous studies on the topic, there still is controversial discussion regarding revascularisation. The first aim of the current study was to investigate the endoligamentous microcapillary revascularisation of the free tendon graft after anterior cruciate ligament replacement with time. Furthermore degeneration and reformation of the extracellular matrix during remodeling of the anterior cruciate ligament graft was to elucidate. Contractile fibroblastic cells expressing the alpha-smooth muscle actin isoform, so called myofibroblasts, have been identified to play a possible role during the healing of the medial collateral ligament by means of restoring the tissue s in situ strain via extracellular matrix contraction. Recently, these cells have also been identified to be a normal part of the human anterior cruciate ligament. It has been hypothesised that myofibroblasts play a role in wrinkling of the extracellular matrix. Therefore the second aim of the current study was to identify myofibroblasts in the intact ovine anterior cruciate ligament and their reoccurrence in a free autologous tendon graft during remodeling after anterior cruciate ligament reconstruction. Thirty-six mature sheep had an anterior cruciate ligament reconstruction with an ipsilateral flexor tendon split graft. Besides conventional staining to analyse total cell density and collagen crimp, midsubstance tissue samples were immunostained for von Willebrandt factor (Factor VIII) to detect the endothelial cells of capillaries and for a-smooth muscle actin to identify myofibroblasts. For vessel detection cross sections of the samples were determined in three zones (subsynovial, intermediate, and center of the graft). Myofibroblast distribution was analysed in longitudinal sections. Evaluation was performed at 6, 9, 12, 24, 52, and 104 weeks by means of histomorphometry using a digital imaging analysis system. The observations showed that capillary vessels, which originate from the synovial envelope, invaded the avascular graft tissue from the surface toward the center zone. The highest level of vascular density was found after 6 weeks, reaching the vascular status of the native anterior cruciate ligament after 24 weeks. Myofibroblasts were identified in the intact ovine anterior cruciate ligament as well as in the flexor tendon graft prior to implantation. During remodeling first myofibroblasts were found at 6 weeks within newly formed fibre bundles. At 24, 52, and 104 weeks myofibroblast distribution and cell density was similar to that of the intact ovine anterior cruciate ligament. The current study has shown, for the first time, the kinetics of an endoligamentous revascularisation of a free tendon graft at the capillary level. In the current model, the process of revascularisation terminated earlier than previously described. Furthermore the current study has shown that alpha-smooth muscle actin containing fibroblastic cells are a regular part of the intact as well as the remodeled anterior cruciate ligament. There is evidence, that myofibroblasts may be involved in maintaining tissue homeostasis in the mature ligament e.g. by means of crimp formation. The presence of these cells during the early remodeling may further indicate that alpha-smooth muscle actin containing fibroblastic cells are involved in the earliest stages of fibre bundle formation.

Einleitung: Die Verwendung der Hamstringsehnen als Transplantate in der rekonstruktiven Chirurgie des vorderen Kreuzbandes stellt eine wenig invasive Alternative zur herkömmlichen Verwendung des mittleren Patellarsehnendrittels dar. Hier ist jedoch die Transplantatverankerung, die bisher meist extrakortikal, also weit entfernt der nativen Kreuzbandinsertion angelegt wurde problematisch. Hierdurch zeigt das Transplantat-Verankerungs-Konstrukt ein unbefriedigendes elastisches und plastisches Dehnungsverhalten, welches u.A. für eine geringere Kniestabilität und eine gestörte ossäre Transplantatintegration verantwortlich gemacht wird. Eine anatomiegerechte Transplantatverankerung auf Gelenkniveau könnte die mechanischen und biologischen Rahmenbedingungen verbessern, um so die Hamstringsehnen als Alternativtransplantat mit verbesserter klinischer Prognose einsetzten zu können. Eine direkte Verankerung mit Interferenzschrauben erlaubt eine solche anatomische Transplantatverankerung, so dass wir dieses neue Operationsverfahren biomechanisch und tierexperimentell untersucht haben. Methoden: In sechs biomechanischen Teilprojekten und in zwei tierexperimentellen Untersuchungen wurde die Eignung der direkten Verankerung mit biodegradierbaren Interferenzschrauben der Hamstringsehnen im Vergleich zu konventionellen Patellar- und Hamstringsehnen-Techniken untersucht. Ergebnisse: Wir konnten demonstrieren, dass die initiale femorale Verankerungsfestigkeit, auch in Sinne der sog. Hybridfixation ausreichend ist. Die tibiale Verankerung unterliegt jedoch verschiedenen Variablen und bedarf einer differenzierten klinischen Anwendung. Im Vergleich zu konventionellen Techniken der Hamstringsehnen-Verankerung kann das plastische und elastische Dehnungsverhalten durch die Verankerung mit Interferenzschrauben deutlich verbessert werden, wobei jedoch das mechanische Verhalten des Patellarsehnen-Transplantates nicht erreicht wurde. Die tierexperimentelle Analyse zeigt auf, dass die ossäre Integration durch die Kompression des Transplantates auf Gelenkniveau soweit verbessert werden kann, dass sog. Tunnelaufweitungen, als Zeichen einer gestörten Einheilung vermieden werden und, dass das Transplantat mit einer direkten Bandinsertion, entsprechend des nativen vorderen Kreuzbandes, auf Gelenkniveau einheilt. Schlussfolgerung: Die hier vorgelegten Untersuchungen haben erstmals umfassend die Rahmenbedingungen der Interferenzschrauben-Verankerung der Hamstringsehnen beschrieben; einer Technik die inzwischen weltweit verbreitete Anwendung findet. Durch eine anatomische Transplantatverankerung auf Gelenkniveau besteht nun die Möglichkeit, mit optimierten mechanischen und biologischen Rahmenbedingungen eine adäquate Alternativtechnik zur konventionellen Verwendung der Patellarsehnen anzubieten. / Introduction: The use of hamstring tendon grafts as a substitute for anterior cruciate ligament reconstruction presents a less invasive procedure compared to the conventional bone-patellar tendon- bone graft. Current techniques of hamstring tendon anterior cruciate ligament reconstruction utilise an extra-cortical fixation. An extra-cortical fixation, however, shows inferior structural parameters with respect to construct slippage or stiffness. These factors may contribute to less stable knees after reconstruction and a delayed osseous integration of the grafted tissue. An anatomic hamstring tendon graft fixation close to the joint line may overcome these problems and may present an alternative to the conventional bone-patellar tendon-bone graft by means of optimised mechanical and biological boundary conditions. We therefore studied anatomic interference fit fixation of hamstring tendon grafts in different mechanical and animal experimental setups. Methods: In six different biomechanical projects and two animal studies, we studied the capability of hamstring tendon interference fit fixation to be used as a secure and reproducible technique of anterior cruciate ligament reconstruction and compared these data to the bone-patellar tendon-bone graft and other conventional hamstring tendon graft fixation techniques. Results: We could demonstrate that the initial femoral fixation strength, as well as a hybrid fixation is sufficient. However, the tibial fixation presents the weak link and underlies different variables, such as bone density and screw geometry. Compared to conventional extra-cortical fixation techniques, the viscoelastic and viscoplastic deformation behaviour could be optimized, but did not reach comparable data to the bone-patellar tendon-bone graft. Animal experiments could clearly demonstrate that interference fit fixation promotes osseous tendon incorporation and minimises the likely hood of a tunnel enlargement. We further found that in contrast to conventional fixation techniques the use of interference screws resulted in the development of a direct ligament insertion anatomy, directly at the joint line, like it is found with the native anterior cruciate ligament. Conclusion: With the present studies we could first describe the mechanical and biological boundary conditions of hamstring tendon interference fit fixation, a technique which gains increased world wide attention as a standard procedure in cruciate ligament surgery. By using an anatomic joint line fixation of hamstring tendon grafts, there are optimised boundary conditions, which therefore presents an adequate alternative to the conventional bone-patellar tendon-bone graft in cruciate ligament reconstruction.

INTRODUÇÃO: As lesões do joelho são muito comuns na prática esportiva, dentre as quais se destaca a lesão do ligamento cruzado (LCA) pela frequência e gravidade. O objetivo deste estudo foi avaliar força muscular concêntrica de abdução e adução do quadril e o equilíbrio postural dinâmico em atletas pós reconstrução de ligamento cruzado anterior. MÉTODOS: Foram avaliados 54 atletas, com média de idade 23,2 ± 4,3 anos, divididos em dois grupos: Grupo LCA (n=27) operados de lesão do LCA e Grupo Controle (n=27) não operados. Foram realizadas a dinamometria isocinética dos abdutores e adutores do quadril e a avaliação do equilíbrio postural dinâmico pelo Y Balance Test (YBT). RESULTADOS: Não houve diferença no escore composto do YBT entre os grupos avaliados; houve diferença do deslocamento anterior no Grupo LCA entre o lado operado e não operado e 63% (17 atletas) mostraram 4 cm ou mais de assimetria entre os membros inferiores. Na avaliação de força e potência muscular dos abdutores do quadril houve maior na atividade muscular do lado operado na velocidade de 60º/segundo e menor na velocidade de 30º / segundo na comparação com o lado não operado. Não houve correlação significativa entre os resultados do YBT com os parâmetros isocinéticos. CONCLUSÃO: O membro operado dos sujeitos avaliados apresentou deficiência do equilíbrio funcional pelo YBT. Não houve perda da força muscular isocinética nos abdutores e adutores do quadril do lado operado. A condição muscular não se associou com a deficiência de equilíbrio / INTRODUCTION: Knee injuries are very common in sports, among which stands out the cruciate ligament injury (LCA) by the frequency and severity. The aim of this study was to evaluate concentric muscle strength of hip abduction and adduction and dynamic postural balance in athletes post reconstruction of anterior cruciate ligament. METHODS: we evaluated 54 athletes, with average age 23.2 ± 4.3 years, divided into two groups: ACL Group (n = 27) operated from ACL injury and control group (n = 27) not operated. The isokinetic dynamometry was carried out of the hip abductors and hip adductors and dynamic postural balance assessment by the Y Balance Test (YBT). RESULTS: there were no differences in the composite score YBT among groups evaluated; there was difference from forward displacement in the ACL Group between operated and non-operated and 63% (17 athletes) showed 4 cm or more of asymmetry between the legs. In the evaluation of strength and muscle strenght of hip abductor the muscular activity was greater at the 60º/second and less at the speed of 30°/second in comparison to the non-operated side. There was no significant correlation between the results of YBT with the isokinetic parameters. CONCLUSION: The operated limb of the subjects showed deficient functional balance by YBT. There was no decrease of isokinetic muscle strength in hip abductors and adductors of the operated side. The muscular condition was not associated with the deficit of balance

O objetivo deste estudo foi comparar o equilíbrio postural entre sedentários e jogadores recreacionais de futebol com e sem reconstrução do LCA usando o Biodex Balance System (BBS). Métodos: é um estudo descritivo transversal, controlado e observacional, sem intervenção terapêutica que avaliou 64 indivíduos do sexo masculino, idade entre 20-40 anos. Foram avaliados três grupos: jogadores de futebol com reconstrução do LCA, jogadores de futebol sem lesão e um grupo de sedentários. Todos os indivíduos realizaram o teste de equilíbrio postural em dois níveis de estabilidade oito (mais estável) e dois (menos estável). Os índices de estabilidade avaliados foram: geral, ântero/posterior e medial/lateral. Resultados: Os resultados da avaliação do equilíbrio postural intragrupo foram: o lado operado dos atletas operados foi mais estável do que o lado não operado. Não houve diferenças entre o lado dominante e não dominante dos grupos de atletas sem lesão e sedentários. Na comparação intergrupos, o lado operado dos atletas operados foi mais estável que o dos atletas sem lesão (lado dominante e não dominante). O grupo dos sedentários foi mais estável que os atletas operados nas duas comparações feitas: com o lado operado e não operado, e que o grupo dos atletas sem lesão: lado dominante e não dominante. Conclusão: O membro operado apresentou maior equilíbrio postural comparado ao lado não operado e ao grupo de atletas sem lesão. Os sedentários apresentaram maior equilíbrio postural comparado aos atletas operados e sem lesão. A dominância dos membros inferiores não exerce influência significante no equilíbrio dos indivíduos sem lesão e sedentários / The objective this study was to compare the postural balance between sedentary recreational players of soccer with and without reconstruction of the LCA using the Biodex Balance System (BBS). Methods: This was a descriptive, transversal, observacional and controlled study, without therapeutic intervention, that evaluated 64 male individuals, aged between 20-40 years, assessed three groups: Soccer players with reconstruction of the LCA, soccer players without injury and a sedentary group. All the individuals realized the test of postural balance in the BBS in two levels of stability: eight (more steady) and two (less steady). The evaluated indexes of stability were: general, anterior/posterior and medial/lateral. Results: The result of the postural balance evaluation in intragroup were: the operated side of the athletes was steadier than the side not operated. There were no difference between the dominant and not dominant side of the athletes without injury and sedentary. In the comparison intergrups, the operated side of the athletes was steadier than athletics without injury. The group of the sedentary was steadier that athletes operated in two comparisons: with operated limb and, not operated, and than the group without lesion: dominant limb and, not dominant. Conclusion: The operated member shown greater postural balance than the not operated side and group of athletes without injury. The Sedentary shown greater postural balance compared to the group of the operated athletes and without injury. The dominance of inferior limbs does not influence significantly in the postural balance in subjects without lesion and sedentary

Rupture of the anterior cruciate ligament (ACL) of the knee leads to chronic joint instability and reduced range of motion while the long term results are marred by a high prevalence of degenerative joint disease especially osteoarthritis. Bundles of collagen threads have been widely investigated for the repair of torn ACL, but are limited by insufficient tissue ingrowth to repopulate and completely regenerate these grafts. We have developed a novel in vitro method of characterizing fiber-based thread matrices by probing their ability to promote tissue ingrowth from a wound margin as a measure of their ability to promote repopulation and regeneration. This method is useful in the optimization of thread scaffolds, and is sensitive enough to distinguish between subtle variations in biopolymer chemistry and organization. Furthermore, this method was used to characterize the effects of crosslinking on the cell outgrowth and correlated the findings with the mechanical properties of collagen threads. The results suggest that crosslinking is required to achieve sufficient mechanical properties for high stress applications such as ACL replacement, but regardless of technique, crosslinking attenuated the cell outgrowth properties of the threads. To improve the regenerative capacity of these scaffolds, novel fibrin microthread matrices were developed with a similar morphology to collagen threads and sufficient mechanical strength to be incorporated in composite thread scaffold systems. These fibrin microthreads were loaded with FGF-2, a potent mitogen and chemotactic agent that works synergistically with fibrin in regulating cell signaling and gene expression. Increases in fibroblast migration and proliferation in FGF-2-loaded fibrin threads were successfully demonstrated with the concomitant promotion of oriented, aligned, spindle-like fibroblast morphology. These results suggest that fibrin-FGF-2 microthreads have distinct advantages as a biomaterial for the rapid regeneration of injured tissues such as the ACL.

O teste do pivot shift é a manobra semiológica mais específica para o diagnóstico da lesão do ligamento cruzado anterior (LCA). É também o único teste que se correlaciona com a probabilidade de desenvolvimento de osteoartrose em joelhos com instabilidade rotacional persistente, após a reconstrução do LCA. Entretanto, há uma grande variabilidade na técnica utilizada para a realização deste teste, comprometendo a sua reprodutibilidade e a sua quantificação objetiva. O teste do pivot shift é influenciado pela associação entre a lesão do LCA e a de outras estruturas anatômicas do joelho. A padronização e a mensuração quantitativa do pivot shift auxiliam na categorização objetiva da frouxidão ligamentar do joelho. O objetivo desta tese foi o de compilar uma série de contribuições do autor, num total de seis publicações, na linha de pesquisa sobre a padronização, quantificação e interpretação do teste do pivot shift. A padronização do teste contribuiu para o aumento da reprodutibilidade da manobra semiológica. Nossos estudos laboratoriais em peças de cadáver demonstraram que a padronização do teste do pivot shift diminuiu de forma significativa a variação da aceleração da redução da tíbia no pivot shift (joelho esquerdo 3,0 ± 1,3 e joelho direito 2,5 ± 0,7 mm/s2) comparada ao teste realizado pela técnica de preferência do cirurgião (joelho esquerdo 4,3 ± 3,3 e joelho direito 3,4 ± 2,3 mm/s2) em cadáver cirurgicamente preparado para apresentar um pivot shift positivo com diferentes gradações em cada joelho. A validação de dispositivos não-invasivos de avaliação da frouxidão ligamentar do joelho, contribuiu para que o teste possa ser medido quantitativamente. Quando comparamos um método invasivo de referência para a mensuração do pivot shift (sensores eletromagnéticos fixados ao osso do fêmur e da tíbia) com três métodos não-invasivos (sensores eletromagnéticos fixados a pele, acelerômetro e um método de análise de imagens), constatamos que todos os métodos não-invasivos apresentaram correlação (r) positiva estatisticamente significante (p <0,01) com o método de referência. Os sensores fixos à pele tiveram r = 0,67 e r = 0,88 para os parâmetros de translação e de aceleração respectivamente. O acelerômetro apresentou r = 0,75 para o parâmetro de aceleração e o método de análise de imagens r = 0,24 para o parâmetro de translação anterior da tíbia. Portanto, neste estudo, métodos não invasivos, adequados para uso em consultório médico, puderam quantificar de forma reprodutível os parâmetros da aceleração e da translação anterior da tíbia no teste do pivot shift. A aplicação clínica destes resultados foi proposta pelo autor por meio de um novo algoritmo para o tratamento individualizado das lesões do LCA, em uma de suas recentes publicações. Embora este algoritmo precise ser validado, a sua proposta abre perspectiva para novos estudos que objetivem melhores resultados no tratamento de pacientes com lesão do ligamento cruzado anterior. / The pivot shift test is the most specific semiologic maneuver to diagnose the anterior cruciate ligament (ACL) injuries. It is also the only test capable of predicting the development of osteoarthritis in the presence of persistent rotatory knee laxity after an ACL reconstruction. However, the test has great technique variability among surgeons compromising reliability and objective quantification. The pivot shift test is influenced by the pattern of the ACL tear and associated lesions. The standardization and the quantitative measurement of the pivot shift can aid in the knee rotary laxity categorization and can provide valuable information on possible additional affected structures besides the ACL, thus contributing for an individualized treatment algorithm for this ligament injury. The purpose of this thesis was to compile a series of author\'s contributions, in a total of six publications, in the field of standardization, measurement and interpretation of the pivot shift test. The standardized technique for the pivot shift test improved the maneuver reliability. Our laboratory studies utilizing cadaveric knees demonstrated that the standardized technique significantly reduced the variation of the acceleration of the tibial reduction during the pivot shift test among surgeons (left knee 3.0 ± 1.3 mm/s2; right knee 2.5 ± 0.7 mm/s2) compared to the surgeons\' preferred technique (left knee 4.3 ± 3.3 mm/s2; right knee 3.4 ± 2.3 mm/s2) in a surgically prepared cadaver for a different positive grade pivot shift in each knee. The validation of non-invasive devices for the knee ligament laxity evaluation aided in the quantitative measurement of the pivot shift. The comparison of an invasive reference method for the pivot shift measurement (electromagnetic tracking device fixed to the femur and tibia) with three non-invasive devices (electromagnetic tracking device attached to the skin, accelerometer and image analysis system) showed statistically significant (p > 0.01) positive correlation (r) for all of them. The electromagnetic tracking device attached to the skin had r = 0,67 and r = 0,88 for the anterior translation and acceleration parameters respectively. The accelerometer has r = 0,75 for the acceleration parameter and the image analysis system had r = 0,24 for the anterior tibial translation parameter. Therefore, in this study, non-invasive methods, affordable for a clinical use, could reliably quantify the acceleration and anterior tibial translation parameters during the pivot shift test. The clinical application of these results was proposed by the author by means of a new algorithm for individualized treatment of the ACL injuries in one of his recent publications. Although this algorithm is yet to be validated, its proposal opens perspective for new studies that aim for better treatment results in patients with an anterior cruciate ligament injury.