862 DISEASES OF THE FETLOCK AND DIGIT. 



iii which the leg is immersed to above the knee, may be continued for 

 several hours every day until pus formation and pain diminish. Dry 

 dressings are then useful. The horse should afterwards have several 

 months' rest and be very slowly brought into training. 



E. DISEASES OF THE FETLOCK AND DIGIT. 



In solipeds, the digit consists of three phalanges, the pastern, coronet, 

 and pedal bones, with two sesamoids at the fetlock, and a third (navicular 

 bone) within the hoof. In ruminants, two completely developed and 

 two rudimentary digits exist, with four sesamoids, and two navicular bones. 

 The pig has four digits, two true and two rudimentary ; eight sesamoid 

 and four navicular bones. 



In the digits of carnivora, the first consists of two, the others of three 

 phalanges. Each digit has two sesamoid bones, whilst the navicular 

 is replaced by a prominence on the third phalanx. 



The horse's fetlock, a complete ginglymoid joint, possesses a capsular 

 ligament, which encloses the joint in front of the lateral ligaments, and 

 its single synovial membrane when distended forms a dilatation which 

 extends upwards between the branches of the suspensory and constitutes 

 " articular wind-gall." The intersesamoid ligament connects the two 

 sesamoid bones, which are attached to the first phalanx by two lateral 

 sesamoid and two inferior sesamoid ligaments, and to the metacarpus 

 by the lateral ligaments of the fetlock and the suspensory. The inferior 

 sesamoid ligaments are three in number : the superficial band is fixed 

 below to the glenoid fibro-cartilage of the second phalanx and above to 

 the base of the sesamoid bones ; the middle ligament is attached to the 

 back of the first phalanx and the base of each sesamoid, while the deep 

 Ligament is represented by a few crossed fibres which connect the sesamoids 

 with the upper part of the back of the first phalanx. The superior 

 sesamoid (suspensory) ligament descends from the lower row of carpal 

 bones and upper end of the metacarpus to near the " buttons " where it 

 bifurcates. Each branch is implanted on the excentric surface of the 

 corresponding sesamoid, and a portion of each band is continued dow nward 

 and forward to join the extensor pedis tendon in front of the pastern. 

 The fetlock joint is so fixed by the upper and lower sesamoid ligaments 

 as to prevent excessive dorsal flexion and assist the function of the flexor 

 tendons. The strong lateral ligaments, assisted by the suspensory in 

 conjunction with the cylindrical form of the articular surface, prevent any 

 side movement. The flexor tendons in crossing the sesamoids are firmly 

 braced in position by a strong aponeurosis which assists in supporting 

 the joint. 



The coronary is an imperfect ginglymoid joint lying about an inch 

 above the upper margin of the hoof. On account of its flat articular 

 surface, it allows of limited side movements, especially when in a position 

 of volar flexion. The anterior capsular ligament is formed by the expanded 

 extensor pedis tendon. At the sides are two stout lateral ligaments, whilst 

 behind is the glenoid fibro-cartilage. The synovial membrane presents 

 posteriorly a dilatation which extends upwards behind the lower part 

 of the first phalanx. Each lateral ligament sends a band downwards 

 to form part of the postero- lateral ligaments of the pedal joint. The 



