SPRAIN OF PERFORATUS AND PERFORANS 129 



SPRAIN OF TENDONS OF FLEXOR PERFORATUS AND 

 FLEXOR PERFORANS 



The tendons of the superficial and deep flexors of the digit are very 

 frequently sprained. The injury may be confined to one or other of 

 the two tendons, or both may be involved. Frequently in addition to 

 the two tendons the suspensory ligament is also sprained. 



When the perforans tendon only is affected, the usual seats of the 

 injury are : 



1. Just below the knee, where the subcarpal or check ligament is 

 united to the tendon. This is the most common seat, and in -this 

 connection the student is here reminded of the slight enlargement 

 which is normally present where the ligament is united to the tendon. 



2. About two inches above the fetlock articulation, just behind the 

 point of bifurcation of the suspensory ligament. This is a common seat 

 in light horses which do fast work. 



3. Below the fetlock, immediately above the heels. This is most 

 commonly met with in race-horses. 



Sprain of the perforatus tendon only, is met with most frequently in 

 the following situations : 



1. In the middle third of the metacarpal region. 



2. Immediately behind the fetlock, slightly below the second seat 

 given in sprain of the perforans. 



3. At the bifurcation of the tendon, just above its insertion. 



In all cases some of the tendon fibres are ruptured, and there is 

 injury to the sheath, which may be lacerated. Exudation takes place 

 as a result of the inflammation set up, and the exudate accumulates in 

 the lymphatic spaces. 



Repair may take place and leave no permanent thickening, but as a 

 rule the tendons remain thickened. The degree of the injury varies 

 from rupture of a few fibres to almost complete rupture of the tendon. 



