Complejo ligamentoso lateral de la articulación talocrural (tobillo): biometría y patrones de división / Lateral ankle ligamentous complex: biometrics and division patterns

El complejo ligamentoso lateral de la articulación talocrural o «tobillo» (CLT) contempla básicamente tres estructuras denominadas como ligamento talofibular anterior (LTFA), ligamento calcaneofibular (LCF) y ligamento talofibular posterior (LTFP). En los últimos artículos publicados en relación con la morfología del CLT, se clasifica al LTFA en tres tipos, basada en el número de bandas o fascículos. Esta variabilidad morfológica plantea nuevos desafíos de estudios anatómicos en la biomecánica y estabilidad de la región talocrural. El objetivo de este estudio fue profundizar la anatomía de este complejo, en base a disecciones por capa que nos permitan visualizar las relaciones existentes entre estos ligamentos y estructuras aledañas. Se utilizaron 10 piezas congeladas pertenecientes al Departamento de Anatomía y Medicina Legal de la Facultad de Medicina de la Universidad de Chile, cuyos ligamentos fueron localizados y medidos en ancho y longitud. Para el LTFA se observó un patrón único en 5 muestras, bifurcado en 4, mientras que en un caso se visualizó un patrón trifurcado. El conocimiento del complejo ligamentoso lateral de tobillo, así como de su dirección, biometría y bandas o fascículos son un importante aporte para la imagenología, rehabilitación, clínica y cirugías que aborden esta región.

SUMMARY: The lateral ankle complex (LAC) basically includes three structures called anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL) and posterior talofibular ligament (PTFL). In recent works published in relation to the morphology of LAC, ATFL is classified into three types, based on the number of bands or fascicles. This morphological modification poses new challenges for anatomical studies in biomechanics and ankle stability. The objective of this is to deepen in greater detail the anatomy of this complex, based on dissections by layer that allow us to study the existing relationships between these ligaments and surrounding structures. 10 frozen pieces belonging to the Department of Anatomy and Legal Medicine of the Faculty of Medicine of the University of Chile were used; whose ligaments were located and measured in width and length. For ATFL, a single pattern was found in 5 samples, bifurcated in 4, while a trifurcated pattern was seen in one case. Knowledge of the lateral ligamentous complex of the ankle, as well as its direction, biometry and bands or fascicles, are an important contribution to imaging, rehabilitation, clinics and surgeries that address this region.

Ankle Ligaments: Comparison of MR Arthrography with Conventional MR Imaging in Amputated Feet

PURPOSE: To compare magnetic resonance (MR) arthrography with conventional MR imaging in the evaluation of ankle ligaments. MATERIALS AND METHODS: Eight freshly amputated human feet underwent conventional MR imaging and MR arthrography. For the former, 1.5-T magnets in the axial, coronal and sagittal planes were used, and T1-weighted sequences were obtained. Following the injection of 6 -10 ml of diluted contrast media (Gd-DTPA 1:250), T1-weighted images were obtained in the same positions as conventional MR images. Paired conventional MR imaging and MR arthrography of each ankle ligament were rated on a five-point scale, and to reflect inter-group differences a Wilcoxon singed-rank test was used to compare the different measurements (p<0.05). In two ankles, MR images of the ligaments were correlated with ankle dissection. RESULTS: Anterior and posterior talofibular ligaments were more clearly revealed by MR arthrography than by conventional MR imaging, while calcaneofibular ligaments showed no difference between these two modalities. With regard to deltoid ligaments, visualization of the anterior and posterior tibiotalar ligament was much improved when contrast material was used to outline the ligament's articular aspect. Visualization of the posterior inferior tibiofibular ligament and inferior transverse ligament were also improved when the use of contrast material provided delineation of the articular side of the ligaments and separated them from adjacent bone. In addition, MR arthrography was very useful for identification of the posterior intermalleolar ligament, though its use did not enhance visualization of the calcaneofibular, tibiocalcaneal, spring or tibiospring ligaments. CONCLUSION: MR arthrography accurately revealed the anatomic details of ankle ligaments, and may therefore be more useful than conventional MR imaging for evaluation of these structures.