LUXATION OF THE FETLOCK JOINT 103 



man. A peculiarity of it in the horse is the preponderance of white 

 fibrous over muscular tissue. 



There are three inferior sesamoidean ligaments, termed respectively 

 superficial, middle, and deep. All are attached superiorly to the bases of 

 the sesamoid bones. Their inferior attachments are as follows : The 

 superficial ligament runs vertically to the superior border of the comple- 

 mentary cartilage of the second phalanx. The middle ligament has two 

 subdivisions. One of these is made up of two bundles of fibres arranged 

 after the manner of the letter V. They are attached to the V-shaped 

 roughened area on the posterior surface of the first phalanx. The other 

 subdivision of this ligament runs vertically, and is attached to the 

 back of the suffraginis within the strands of the V-shaped division. The 

 deep ligament has two strands of fibres, which cross one another and 

 are attached inferiorly to the upper extremity of the back of the 

 suffraginis. 



The fetlock has a single synovial membrane. In front and laterally 

 it is supported by the anterior common and lateral ligaments. Posteriorly 

 the sesamoid bones support it. Above these bones it is unsupported, whilst 

 below them it is supported by the deep inferior sesamoidean ligament. 



The fetlock joint is capable of flexion and extension. Lateral move- 

 ment is restricted by the lateral ligaments. When the joint is completely 

 flexed, however, it is capable of slight lateral movement, since the lateral 

 ligaments are then slightly relaxed. 



DISEASES OF THE FETLOCK 



LUXATION OF THE FETLOCK JOINT 



Luxation of the fetlock joint is rare. This is readily under- 

 stood when we consider the firm manner in which the bones are 

 bound together by ligaments. The strong anterior common ligament 



