A comparative immunohistochemical and quantitative study of the epiligament of the medial collateral and anterior cruciate ligament in rat knee / Estudio inmunohistoquímico y cuantitativo del epiligamento del ligamento colateral medial y cruzado anterior en rodilla de rata

SUMMARY: The aim of the present study was to evaluate the importance of the epiligament for the difference in the healing potential of the knee anterior cruciate and medial collateral ligament. To do so, we compared the structure of the anterior cruciate and the medial collateral ligament and evaluated the differences in the expression of collagen types I, III and V in a rat knee. We have also conducted a comparative quantitative analysis of the number of cells per mm2 in the two ligaments. Tissue samples were obtained from the anterior cruciate and medial collateral ligament of 10 knee joints taken from five 8-month-old Wistar rats. We used standard hematoxylin and eosin staining, in addition to immunohistochemical staining with monoclonal antibodies against collagen types I, III and V. A semi-quantitative analysis of the expression was made through ImageJ, while Student's T-test was used for the statistical analysis. Our results showed higher expression of all collagen types in the epiligament, compared to the ligament proper and difference in the expression between the medial collateral and the anterior cruciate ligament in favor of the first. We also reported a statistically significant difference in the number of cells per mm2 between the two ligaments and their epiligaments. Our findings show a higher number of cells and a stronger expression of certain collagen types in the epiligament of the medial collateral compared to the anterior cruciate ligament, which may be related to the difference in their healing potential.

RESUMEN: El objetivo del presente estudio fue evaluar la importancia del epiligamento para la diferencia en el potencial de curación del ligamento cruzado anterior y colateral medial de la rodilla. Comparamos la estructura del ligamento cruzado anterior y el ligamento colateral medial y evaluamos las diferencias en la expresión de los tipos de colágeno I, III y V en una rodilla de rata. También se realizó un análisis cuantitativo comparativo del número de células por mm2 en los dos ligamentos. Se obtuvieron muestras de tejido del ligamento cruzado anterior y colateral medial de 10 articulaciones de rodilla tomadas de cinco ratas Wistar de 8 meses de edad. Utilizamos tinción estándar con hematoxilina y eosina, además de tinción inmunohistoquímica con anticuerpos monoclonales contra colágeno tipo I, III y V. Se realizó un análisis semicuantitativo de la expresión mediante ImageJ, mientras que para el análisis estadístico se utilizó la prueba T de Student. Nuestros resultados mostraron una mayor expresión de todos los tipos de colágeno en el epiligamento, en comparación con el ligamento y una diferencia en la expresión entre el ligamento colateral medial y el ligamento cruzado anterior. También informamos una diferencia estadísticamente significativa en el número de células por mm2 entre los dos ligamentos y sus epiligamentos. Nuestros hallazgos muestran un mayor número de células y una expresión mayor de ciertos tipos de colágeno en el epiligamento colateral medial en comparación con el ligamento cruzado anterior, lo que puede estar relacionado con la diferencia en su potencial de curación.

Reconstrucción ligamento patelofemoral medial / Medial patellofemoral ligament reconstruction

La reconstrucción del ligamento patelofemoral medial (LPFM) se ha convertido en un procedimiento quirúrgico habitual en el tratamiento de la luxación recidivante de rótula. Se describe una técnica de la reconstrucción del LPFM utilizando injerto autólogo de semitendinoso. Este artículo presenta la anatomía del ligamento, las indicaciones de la cirugía y describe la técnica quirúrgica utilizada. La técnica comienza con una artroscopía diagnóstica, luego se obtiene el injerto de semitendinoso y se realiza una incisión en el borde medial de la rótula. Se crea un hueco sobre el borde interno de la misma y se fija el injerto con un tornillo de tenodesis. La fijación femoral se realiza en el sitio de inserción anatómica mediante un tunel y un tornillo interferencial. Esta técnica evita la creación de un tunel completo en la patela lo cual debilita en menor medida la estructura ósea y además logra una fijación estable que permite una rehabilitación precoz.

Importance of the different posterolateral knee static stabilizers: biomechanical study

PURPOSE: The purpose of this study was to evaluate the relative importance of the different static stabilizers of the posterolateral corner of the knee in cadavers. METHODS: Tests were performed with the application of a varus and external rotation force to the knee in extension at 30 and 60 degrees of flexion using 10 cadaver knees. The forces were applied initially to an intact knee and then repeated after a selective sectioning of the ligaments into the following: section of the lateral collateral ligament; section of the lateral collateral ligament and the popliteofibular complex; and section of the lateral collateral ligament, the popliteofibular complex and the posterolateral capsule. The parameters studied were the angular deformity and stiffness when the knees were submitted to a 15 Newton-meter varus torque and a 6 Newton-meter external tibial torque. Statistical analysis was performed using the ANOVA (Analysis of Variance) and Tukey's tests. RESULTS AND CONCLUSION: Our findings showed that the lateral collateral ligament was important in varus stability at 0, 30 and 60 degrees. The popliteofibular complex was the most important structure for external rotation stability at all angles of flexion and was also important for varus stability at 30 and 60 degrees. The posterolateral capsule was important for varus stability at 0 and 30 degrees and for external rotation stability in extension. Level of evidence: Level IV (cadaver study).

Metric measurements and attachment levels of the medial patellofemoral ligament: an anatomical study in cadavers

OBJECTIVE: To determine the metric measurements and to verify the attachment levels of the medial patellofemoral ligament in human cadavers. METHODS: Seventeen knees (eight right and nine left knees) from 10 cadavers (nine male and one female) were dissected and stored in a 10 percent formaldehyde solution. All of the knees were whole and did not show any macroscopic signs of injuries. RESULTS: The medial patellofemoral ligament was present in 88 percent of the knees studied, localized transversally between the medial femoral epicondyle and the medial margin of the patella. Its dimensions were quite variable, even between the knees of the same individual. The width of the patellar insertion ranged from 16 to 38.8 mm, with a mean of 27.90 mm, and its mean length was 55.67 mm. The margins of the ligament were concave or rectilinear. At the upper margin, the concave form predominated and was better characterized, while at the lower margin, the rectilinear form predominated. CONCLUSIONS: The medial patellofemoral ligament is a very distinct structure with variable anatomical aspects and is always located in a plane inferior to the vastus medialis obliquus muscle.

Quantitative and descriptive analysis of the meniscotibial ligament in human corpses

The meniscotibial ligaments (LMT) of humans are capsular fibers with proximal origin in the lateral border of the menisci and distal insertion in the lateral border of the tibial condyle, also called coronary ligament of the knee. However, few studies describe the presence, course and anatomical variations of this ligament. Our objective was to evaluate the LMT through quantitative and descriptive methods. Eighty-five knees were examined(42 right knees [RK] and 43 left knees [LK]), dissected, evaluated, catalogued and photographed by four examiners. Twenty knees (23.53%) presented LMT, 6 (30%) in RK and 14 (70%) in LK. In two RKs, the LMT presented proximal insertion in the medial menisci and distal insertion in medial tibial condyle; in the other ones, the LMT presented proximal insertion in the lateral menisci and distal insertion in the lateral tibial condyle. In the LK, four LMT presented proximal insertion in the medial menisci and distal insertion in the medial tibial condyle, while the other ones presented proximal insertion in the lateral menisci and distal insertionin the lateral tibial condyle. One LMT in the LK presented proximal and distal insertion in both menisci and tibial condyle. The analysis of human corpses in our study suggests that the presence of the LMT is much more common in the LK than in the RK, with more frequent insertion in the proximal region of the lateral menisci and distal insertion in the lateral tibial condyle.

Estudo anatômico e artroscópico do ligamento femoropatelar medial / Anatomic and arthroscopic study of the media femoropatellar ligament

Os autores estudaram em joelhos de 11 cadáveres a presença do ligamento femoropatelar medial. Em 6 joelhos o estudo foi anatômico por dissecação e secção seriada das peças anatômicas. Em 5 joelhos o estudo foi artroscópico pela visibilização nos joelhos do ligamento encontrado nos seis joelhos estudados antomicamente. Em todas as peças anatômicas foi possível a dissecação da estrutura ligamentar descrita como o ligamento femoropatelar medial e nos cinco joelhos estudados sob visão artroscópica a visibilização e identificação do ligamento foi evidente.

Estudo mecänico dos complexos colaterais do joelho / Mechanical study of collateral complexes of the knee

Os autores realizaram estudo biomecânico dos complexos colaterais medial e lateral de 40 joelho de cadáveres frescos, com o objetivo de compara-los entre si e estabelecer relaçöes com a idade, peso e a altura dos espécimes. Após a análise dos dados, constatam que näo existe diferença entre os lados e nem entre os complexos colaterais mediais e laterais, sendo que o limite de resistência varia inversamente com peso para ambos os complexos colaterais e a idade relaciona-se inversamente com o complexo colateral lateral