Ji Hyun Kim1, Zhe-Wu Jin2, Shogo Hayashi3, Gen Murakami4, José Francisco Rodríguez-Vázquez5, Hiroshi Abe6. 1. Department of Anatomy, Jeonbuk National University Medical School, Geunji-ro 20, Deukjin-gu, Jeonju, 54907, Korea. 407kk@hanmail.net. 2. Department of Anatomy, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, China. 3. Department of Anatomy, Division of Basic Medicine, Tokai University School of Medicine, Isehara, Japan. 4. Division of Internal Medicine, Cupid Clinic, Iwamizawa, Japan. 5. Department of Anatomy and Embryology, School of Medicine, Complutense University, Madrid, Spain. 6. Emeritus Professor of Akita University School of Medicine, Akita, Japan.
Abstract
BACKGROUND AND PURPOSE: Ankle sprain is often attributed to damage of the anterior and posterior talofibular ligaments (ATFL, PTFL). We compared the morphology of these ligaments in fetuses of different gestational ages (GAs) with the horizontal configuration in adults. MATERIALS AND METHODS: Histological sections of unilateral ankles were examined in 22 fetuses, 10 at GA of 9-12 weeks and 12 at GA of 26-39 weeks. RESULTS: At a GA of 9 to 10 weeks, the ATFL and PTFL consisted of horizontally running straight fibers. The initial ATFL appeared as a thickening of the capsule of the talocrural joint, although the initial PTFL was distant from this joint. Until a GA of 12 weeks, the talus and fibula were separated by an expanding joint cavity. Thus, the initial horizontal ligaments were "pulled" in a distal direction. The distal parts of the ligaments consisted of thin collagenous fibers that had an irregular array, whereas the short proximal parts had thick fibers and a horizontal array. In near-term fetuses, the ligaments contained no horizontal fibers. The ATFL had a wavy course around the thick synovial fold, and was exposed to the joint cavity along the entire course; the distal part was thinner than the proximal part. The PTFL was bulky and consisted of fibers with an irregular array. Therefore, the morphology in a near-term fetus was quite different from that in adults. CONCLUSION: The horizontal and straight composite ankle fibers in adults apparently result from postnatal reconstruction, depending on mechanical demand.
BACKGROUND AND PURPOSE: Ankle sprain is often attributed to damage of the anterior and posterior talofibular ligaments (ATFL, PTFL). We compared the morphology of these ligaments in fetuses of different gestational ages (GAs) with the horizontal configuration in adults. MATERIALS AND METHODS: Histological sections of unilateral ankles were examined in 22 fetuses, 10 at GA of 9-12 weeks and 12 at GA of 26-39 weeks. RESULTS: At a GA of 9 to 10 weeks, the ATFL and PTFL consisted of horizontally running straight fibers. The initial ATFL appeared as a thickening of the capsule of the talocrural joint, although the initial PTFL was distant from this joint. Until a GA of 12 weeks, the talus and fibula were separated by an expanding joint cavity. Thus, the initial horizontal ligaments were "pulled" in a distal direction. The distal parts of the ligaments consisted of thin collagenous fibers that had an irregular array, whereas the short proximal parts had thick fibers and a horizontal array. In near-term fetuses, the ligaments contained no horizontal fibers. The ATFL had a wavy course around the thick synovial fold, and was exposed to the joint cavity along the entire course; the distal part was thinner than the proximal part. The PTFL was bulky and consisted of fibers with an irregular array. Therefore, the morphology in a near-term fetus was quite different from that in adults. CONCLUSION: The horizontal and straight composite ankle fibers in adults apparently result from postnatal reconstruction, depending on mechanical demand.
Authors: Fidel Hita-Contreras; Antonio Martínez-Amat; Raúl Ortiz; Octavio Caba; Pablo Alvarez; José C Prados; Rafael Lomas-Vega; Antonia Aránega; Indalecio Sánchez-Montesinos; Juan A Mérida-Velasco Journal: J Anat Date: 2012-03-19 Impact factor: 2.610