IN THE KEGION OF THE FEMORO-TIBIAL ARTICULATION. 105 



Palpation. — Generally the patella cau be readily felt in 

 its abnormal place, while the capsular ligament is rather 

 prominent below the knee. 



Differential Diagnosis. — Crural nerve paralysis and rupture 

 of the muscles, extending the stifle joint, shows similar 

 symptoms, but careful palpation and the abnormal position 

 of the patella usually suffice to settle the question. (See 

 page 97.) 



4.— Rupture of the Straight Ligaments 

 of the Patella. 



History. — Lameness following external violence, jumping 

 and slipping. 



Inspection. — In rupture of the outer straight ligament, 

 which seems to be the one most frequently involved, decided 

 supporting-leg lameness is the result. At first it is so severe 

 that no weight at all is borne by the lame leg, but later on 

 some weight is sustained. 



Palpation. — Unless swelling has set in, which is hot and 

 very painful, mainly below the patella, the presence of the 

 internal and the middle straight ligaments can be established. 

 The gap in the external straight ligament suggests rupture. 



5. — Fracture of the Patella. 



History. — Lameness following falls and external violence. 

 This trouble is rare in the horse^ 



Inspection. — Severe supporting-leg lameness. Any move- 

 ment is carefully avoided, apparently causing intense pain. 

 After a while swelling about the patellar region is noticeable. 



Palpation. — Crepitation is usually absent, and unless the 

 swelling interferes, the broken pieces can be felt. 

 Manipulation of the parts is painful. 



