Dr Apoorva D1 , Dr Lalitha C2 , Dr Girish V Patil3 Assistant Professor, Dept of Anatomy, DM WIMS, Meppadi, Kerala
Professor, Dept of Anatomy, Kempegowda Institute of Medical Sciences, Bangalore
Associate Professor, Dept of Anatomy, DM WIMS, Meppadi, Kerala
Ankle joint (talocrural) is a hinge joint. The ligaments of the ankle joint are medial and lateral collateral ligaments. Medial deltoid ligament has superficial and deep components. Lateral collateral ligament has Anterior Talofibular (ATFL), Calcaneofibular (CFL) and Posterior Talofibular ligaments (PTFL) as three discrete parts. These two major ligamentous complexes are the main stabilizers of ankle joint which are appreciated both in MRI and cadaveric dissections. Ankle sprains are most common in atheletes and in other sports like basketball, soccer, football and volleyball. Lateral ankle sprains account for about 85% of all ankle sprains; with anterior talofibular ligament being the most frequently injured. Morphometry and variations of ligaments of ankle has not been well documented in literature. Hence this study has been taken up. Study was done by dissection on 60 cadaveric lower limbs, irrespective of sex from the Department of Anatomy, Kempegowda Insitute Of Medical Sciences, Bangalore.
By dissection, both single (18%) as well as double banded (82%) ATFL were found. The average length and width of ATFL irrespective of side was noted. There was no statistical significance in the values between the right and the left ankles.
The data represented in this study may be important when considering surgical repair or reconstruction of traumatized or attenuated collateral ligaments.
Introduction “Ligament” most commonly refers to a band of tough, fibrous dense regular connective tissue bundles, made of attenuated collagenous fibers; with said bundles protected by dense connective tissue sheaths. Ligaments connect bones to other bones to form a joint. Some ligaments limit the mobility of articulations, or prevent certain movements altogether
The ankle or talocrural region is the region where the foot and the leg meet.1
Ankle joint (talocrural) is a hinge joint, formed by the lower end of tibia, its medial malleolus, together with the lateral malleolus of the fibula and inferior transverse tibiofibular ligament, forms a deep recess for the body of the talus.
The ligaments of the ankle joint are medial and lateral collateral ligaments.2
Acute injuries of the ankle are the most common type of injury seen by general practitioners and emergency departments. They involve about 25% of all injuries of the musculoskeletal system with over 20000 cases occurring in USA everyday. Inversion trauma constitutes a large percentage of these injuries. In about 10% to 15% of all inversion injuries, there is rupture of the lateral ligaments of the ankle with involvement of the anterior talofibular ligament.1
The Anterior TaloFibular Ligament( ATFL ) is the most frequently injured ligament of the ankle and is the most frequently observed injury in the emergency room. This ligament plays an important role in limiting anterior displacement of the talus and plantar flexion of the ankle.
The ATFL is the weakest of the three lateral ankle ligaments, having the least elastic transformation properties. The ATFL is a flat, quadrilateral ligament that is incorporated in the joint capsule and passes from the distal area of the anterior margin of the lateral malleolus to the body of the talus just infront of the cartilaginous margin of its lateral
articular surface. The ligament is approximately 6- 10 mm in width, 15 – 20 mm in length and 2 mm in thickness.3
The center of the ligament is on an average of 10mm proximal to the tip of the fibula as measured along the axis of the fibula. The overall width does not appear to vary greatly irrespective of the number of bands present, suggesting that the variations observed do not modify the ligaments function. From its origin, it runs anteromedially to insert on the talar body immediately anterior to the joint surface occupied by the lateral malleolus. They also described that, in plantar flexion, the inferior band of the ligament remains relaxed while the upper band becomes taut. In dorsiflexion, the upper band becomes relaxed and the inferior band becomes tight.
The ligament is closely related to the joint capsule and is typically composed of two separate band. The bands are separated by vascular branches from the perforating peroneal artery and its anastomosis with the lateral malleolar artery.
The ligament is virtually horizontal to the ankle in the neutral position but incline upward in dorsiflexion and downward in plantar flexion. In plantarflexed position , the ligament comes under strain and is vulnerable to injury, particularly, when the foot is inverted. Also, in cases of two banded ATFL, the inferior band of the ligament remains relaxed while the upper band becomes taut. In dorsiflexion, the upper band remains relaxed and the inferior band becomes tight.4
Figure 1: Normal lateral collateral ligament complex of ankle joint MATERIALS AND METHODS Study was conducted on 60 formalin fixed adult cadaveric lower limbs, irrespective of sex from the Department of Anatomy, Kempegowda Insitute Of Medical Sciences, Bangalore.
Cadavers with congenital abnormalities of ankle like club foot or congenital Talipus Equino Varus were excluded from the study.The study was conducted by dissection of ankle region according to Cunningham’s manual. Variations of the ligament were noted and their length and breadth measurements were taken. The ligament length was measured from one insertion point to another on the opposite borders of the ligament, i.e free length. Width was measured at three points; proximal insertion site, the distal insertion site and midway between the two for ATFL.
Values were compared with previous studies for their statistical significance. The data obtained was analyzed by computing descriptive statistics arranged in tabular form and compared with the other studies available in the literature and conclusions were drawn.
RESULTS Both double as well as single banded ATFL were found in the present study. Double banded ATFL had superior as well as inferior bands.