FRACTURE OF THE PATELLA 59 



FRACTURE OF THE PATELLA 



This is usually due to a blow, such as a kick, or it may be caused by 

 the stifle being flexed to an extraordinary degree. Owing to the manner in 

 which the ligaments and tendons are inserted into the front of the patella, 

 fractures which are due to violent muscular contraction are usually in 

 the horizontal direction. When the fracture is due to a blow, the 

 bone is usually broken into several pieces, and the fracture is of the 

 comminuted variety. The numerous ligaments and tendons which are 

 attached to the patella are more or less connected with one another by 

 a plentiful supply of fibrous tissue in the part. After the infliction of 

 the injury, therefore, this binding structure has the effect of keeping the 

 fractured pieces in position, so that there is rarely any displacement. It 

 will thus be understood that crepitation is not frequently a symptom of 

 fracture of the patella, and on account of the numerous structures which 

 are attached to the bone, there will be inability on the part of the animal 

 to move without being subjected to great pain. 



The patella is not a bone which lends itself readily to the healing 

 of fractures, and this is particularly so when the fracture concerns the 

 inferior portion of the bone. This is due to the fact that the nutrient 

 vessels of the bone pierce its superior surface and the lower portion is very 

 poorly supplied with blood. 



Treatment of fractured patella in the human subject by the insertion 

 of ivory connecting pegs or screws of steel or silver, has in recent years 

 met with a considerable amount of success. In equine practice, however, 

 prognosis is usually unfavourable, particularly when the joint is associated 

 with the injury, as is very frequently the case. The animal should be 

 placed in slings, and adhesive strapping applied to the joint to keep the 

 part as still as possible. Further than this, little can be done. 



