98 THE SURGICAL ANATOMY OF THE HORSE 



which extends the articular surface of this bone. The inferior insertion 

 of each of these ligaments is into the anterior tuberosity of the tibia. 

 The middle ligament is attached to the lower part of the vertical groove 

 which this tuberosity presents, and the remaining two to the elevated 

 portions of the tuberosity, which bound this groove. The middle 

 ligament is more deeply seated than the other two, and is embedded in a 

 pad of fat. Between this ligament and the groove on the anterior tibial 

 tuberosity, is placed a small synovial bursa which facilitates the 

 movements of the ligament. 



The external ligament is the largest and most powerful of the three. 

 It is in the form of a strong, flattened band. A tough aponeurotic sheet, 

 which is a dependency of the Fascia Lata, runs from this ligament over 

 the middle band to be attached to the internal ligament. 



The internal ligament is also in the form of a flattened band. It is 

 longer than the external but it is not so powerful. The aponeurosis of 

 the adductor muscles of the leg is confounded with the inner aspect of 

 this ligament. 



The anterior face of the straight patellar ligaments gives attachment 

 to the common tendon of insertion of the quadriceps extensor cruris 

 muscles. When these muscles contract, therefore, the patella is drawn 

 upwards, and the straight ligaments are made tense, the stifle being 

 extended by the action of the muscles being transmitted to the tibia 

 through the medium of the ligaments. 



The Femoro-tibial Ligametits. — Of these there are five, namely, two 

 crucials, two laterals and a posterior. 



The Crucial Ligaments. — These are termed anterior and posterior 

 respectively. They are placed in the middle of the joint, and to expose 

 them satisfactorily a vertical and antero-posterior section of the joint 

 should be made. 



The Anterior Crucial Ligament. — This is the more external of the 

 two ligaments. It is much the shorter. It is a strong, fibrous cord 

 which is attached superiorly to the posterior part of the inner surface 



