The Meniscofemoral Ligament Mimicking a Lateral Meniscus Tear

A 58-year-old male patient who had developed left knee pain with a history of trauma was referred to our hospital. Physical examination and further examination by magnetic resonance imaging revealed results that closely resemble a horizontal tear of the lateral meniscus and a tear of the medial meniscus. Arthroscopically, we found a cord-like structure originating from the posterior 1/3 portion of the lateral meniscus and passing obliquely toward the medial femoral condyle in front of the posterior cruciate ligament without a tear of the lateral meniscus. In this report, we describe a rare case of anterior meniscofemoral ligament that was clearly seen on arthroscopy and mimicked a meniscal tear, which is also known as a pseudo-tear of the meniscus.

Relaciones anatómicas y correlaciones estadísticas entre los ligamentos meniscofemorales y el ligamento cruzado posterior en individuos chilenos / Anatomical relationships and statistical correlations between the meniscofemoral ligaments and the posterior cruciate ligament in Chilean individuals

Entre las estructuras que conforman la articulación de la rodilla, los ligamentos meniscofemorales (LMF) son considerados como elementos inconstantes, que están en relación al ligamento cruzado posterior (LCP). Con el propósito de correlacionar los LMF con el LCP y clasificar al ligamento meniscofemoral posterior (LMFP) con respecto al LCP, se estudiaron 30 rodillas de individuos Chilenos, fijadas en formaldehído al 10 % y pertenecientes a los Laboratorios de Anatomía, de la Facultad de Medicina de la Universidad Católica del Maule. Las medidas fueron registradas con un cáliper electrónico y se fotografiaron las muestras. Con respecto al trayecto de las fibras del LMFP, se observó un trayecto recto en 76 % los casos (tipo I) y sus fibras rotando sobre su eje en el porcentaje restante (tipo II). Además las fibras del LMFP se fundieron con las del LCP (66,7 %) y en menor porcentaje van directa e independientemente al cóndilo femoral medial. Se obtuvieron los promedios y se correlacionaron las variables a estudiar. De esta manera se determinó que existe correlación entre la distancia epicóndilo lateral del fémur- maleólo lateral (ELF-ML) y la longitud del LCP, y de esta misma distancia con la longitud del LMFP. Además hay correlación entre la longitud del LCP y la longitud del LMFP.

Among the structures that make up the knee joint, the meniscofemoral ligaments (MFL) are considered unstable elements which are related to the posterior cruciate ligament (PCL). In order to correlate the MFL with the PCL and classify the posterior meniscofemoral (PMFL) with respect to PCL, 30 fixed knees of Chilean individuals were studied, all belonging to the Anatomy Laboratory of the Faculty of Medicine of the Universidad Catolica del Maule, Chile. The measures were recorded with an electronic caliper and samples were photographed. Regarding course of fibers of the PMFL, 76 % of the cases had a straight direction (type I) and 24 % had a rotation on its axis (type II). In addition, the fibers of PMFL were fused with PCL (66.7 %) and a lower percentage reached directly and independently to the medial femoral condyle. Averages were obtained and correlated. Thus, it was determined that there is correlation between the lateral epicondyle of the femur-lateral malleolus distance (LEF-LM) and the length of the PCL, and this same distance with de PMFL length. Also there was correlation between the length of the PCL and the length of PMFL.

Características biométricas de los ligamentos meniscofemorales en individuos chilenos / Biometrical characteristics of meniscofemoral ligaments in Chilean individuals

El conocimiento de los ligamentos meniscofemorales anterior y posterior (LMFA y LMFP) es de gran importancia para la anatomía y clínica quirúrgica. Con el propósito de efectuar un análisis de su frecuencia y biometría en individuos Chilenos, se disecaron 30 rodillas, de cadáveres de individuos adultos, de sexo no conocido, fijadas en formaldehído al 10 % y pertenecientes a los Laboratorios de Anatomía, de la Facultad de Medicina de la Universidad Católica del Maule, Chile. Utilizando un caliper digital se registraron medidas de longitud, ancho y espesor de los mismos a diferentes niveles. Todas las muestras fueron fotografiadas. En relación a la frecuencia, el LMFP se presentó en 21 casos (70 %) y el LMFA en 13 (43,4 %). La longitud promedio del LMFA fue de 29,04±2,66 mm y la del LMFP de 27,46±3,08 mm; el ancho proximal del LMFA fue de 9,88±4,34 mm y la del LMFP de 6,55±2,14 mm; el espesor promedio del LMFA fue 1,19±0,47 mm y el del LMFP de 1,8±0,68 mm. Los otros resultados registrados se muestran en el texto correspondiente. Los resultados obtenidos son un aporte al conocimiento anatómico de los ligamentos de la articulación de la rodilla en nuestra población.

The knowledge of the meniscofemoral ligaments (MFL) is of great importance to the anatomy and surgical clinic. In order to conduct an analysis of their frequency and biometry in Chilean individuals, 30 knees of corpses of adult individuals, sex unknown, fixed in 10 % formaldehyde and belonging to the Laboratory of Anatomy, Faculty of Medicine of the Universidad Católica del Maule, Chile. Using a digital caliper, measurements of length, width and the thickness to different levels were recorded. All the samples studied were photographed. Regarding frequency, PMFL occurred in 21 cases (70 %) and AMFL in 13 (43.4 %). The average length of AMFL was 29.04±2.66 mm and the PMFL 27.46±3.08 mm; the proximal width of the AMFL was 9.88±4.34 mm and the PMFL of 6.55±2.14 mm and the average thickness of the AMFL was 1.19±0.47 mm and the PMFL of 1.8±0.68 mm. Other measurements are shown in the text. The obtained results are a contribution to the knowledge of ligaments of the knee joint in our population.

Anterolateral Meniscofemoral Ligament of the Lateral Meniscus

Anatomical variations of the meniscus are a common anomaly that knee surgeons frequently encounter. However, anomalies of the anterior horn of the lateral meniscus (AHLM) are extremely rare. In this report, we present a newly discovered anomaly of the AHML: an anterolateral meniscofemoral ligament is described with clinical features and radiographic and arthroscopic findings.

Meniscus Hoop Tensioning Function of the Meniscofemoral Ligament: An Experimental Study Using the Knee Joint of the Pig

PURPOSE: To prove experimentally if the posterior meniscofemoral ligament (PML) has hoop tensioning function for the lateral meniscus using the knee joint of the pig. MATERIALS AND METHODS: Amputated stumps with the knee joint of the pig (Yorkshire) were used. The experiment was performed under 6 conditions; 1) intact PML with intact lateral meniscus (LM), 2) intact PML with radial tear of posterior horn of LM, 3) intact PML with total lateral meniscectomy, 4) cut PML with intact LM, 5) cut PML with radial tear of posterior horn of LM, and 6) cut PML with total lateral meniscectomy. The pressure-sensitive film (Prescale,Fuji) was inserted under the lateral femoral condyle and axial loads was transmitted to the knee joint with universal testing machine (Instron, model No.4469, USA). The pressed area, maximum pressure and average pressure were measured by the Prescale imaging analysis system FDP-901E series. RESULTS: With the intact PML, there was little difference in pressed area and maximum and average pressures between the conditions of intact meniscus and radial tear of posterior horn of LM. With the cut PML, regardless of the states of the LM, pressure concentration (much decreased pressed area, and increased maximum and average pressures) occurred, which had similar results to the condition of total lateral meniscectomy with intact PML. CONCLUSION: The PML of the pig had hoop tensioning function for the LM under axial loads.