836 RUPTURE OF THE FLEXOR TENDONS AND SUSPENSORY LIGAMENT. 



lameness. Either no weight can be borne by the limb, or if weight 

 is placed on it for a moment the affected joint is abnormally 

 flexed ; this symptom, however, is less marked in rupture of the 

 perforatus tendon. In consequence of the dorsal flexion of the 

 coronet-joint, the toe of the foot is directed upwards. Rupture 

 of the superior sesamoid ligament produces abnormal dorsal flexion 

 of the fetlock (Fig. 478), but the toe retains its normal position. 

 The same is true of ruptures of the inferior sesamoid ligaments. 

 In rupture of the flexor perforans, all three phalangeal joints show 

 abnormal dorsal flexion, the hoof sometimes only touching the 

 ground at the heels. Unless swelling has become pronounced the 

 rupture may be detected by palpation. The degree of pain varies 

 greatly ; usually the animal is very restless. 



Course. Ruptures of the flexor tendons, excepting those following 

 neurectomy, unite regularly and completely, provided the- ends of 

 the tendon are not too far apart. The extent to which the ends of 

 the tendons are displaced may be estimated from the change in 

 position of the fetlock. Under favourable circumstances, rupture of 

 the flexor perforans or perforatus unites in six weeks, though two 

 to three months may elapse before the animal is fit for use. A 

 race-horse which had suffered rupture of the suspensory ligament, 

 with fracture of a sesamoid, in one fore limb was no better after 

 six weeks. It was killed, and on post-mortem it was found that 

 though union had begun, yet there was no visible callus formation 

 between the displaced fragments of the sesamoid bone. 



Ruptures of one branch of the suspensory ligament unite in 

 from six to eight weeks, usually without leaving any lameness. The 

 condition is much more grave when the rupture occurs above the 

 bifurcation of the ligament. In rupture of the tendons following 

 neurectomy or necrosis the prognosis is hopeless. 



Treatment of complete ruptures is generally useless, because in 

 the majority of cases it is accompanied by much deformity of the 

 limb, and degenerative changes in the tendons. Even in the most 

 favourable cases where the tendon substance is normal, treatment 

 is confined to bringing the divided parts as near together as possible 

 and fixing them, for which purpose plaster bandages are useful. If 

 the animal be quiet, an iron splint fixed to the heel of a bar shoe 

 and of a curve corresponding to the normal position of the fetlock 

 is useful in rupture of either flexor above the fetlock. After covering 

 the foot with a pad to equalise pressure, the splint is padded and 

 fixed in position by means of circular bandages. Slinging is generally 

 necessary when using this apparatus. 



