CHAPTER III. 



DISEASES OF THE SYNOVIAL MEMBRANES AND 

 OF THE ARTICULATIONS, 



I.— SYNOVIAL MEMBRANES AND ARTICULATIONS. 

 SYNOVITIS. 



Inflammation of the synovial membranes, or synovitis, may affect the 

 synovial sacs either of the joints or of the tendon sheaths. It may be 

 acute or chronic and occur either idiopathically or follow the infliction of 

 an injury. Its two chief forms are simj^le, or " closed," synovitis and 

 suppurative, or " open," synovitis, the essential distinction between which 

 is that in the latter micro-organisms are present, whilst in simple 

 synovitis they are absent. In all cases the disease is characterised by 

 distension of the sac affected. 



Synovitis produced by a wound communicating with the outer air 

 may be complicated by suppuration, and if the synovial membrane of a 

 joint be involved the primary synovitis is almost always followed by 

 traumatic arthritis. 



The commonest forms of chronic simple synovitis are : — 



INFLAMMATION OF THE PATELLAR SYNOVIAL CAPSULE. 



Liflammation of the synovial membrane of the femoro-patellar joint 

 is most commonly seen in working oxen as a consequence of strains 

 during draught. It is also found in young animals which have 

 injured the synovial capsule through falls, slips, or over-extension of 

 the limb. 



Symptoms. Development is slow and progressive, and injury may 

 not be discovered until the lameness which follows has become fairly 

 marked. This lesion is characterised by swelling in the region of the 

 stifle. On palpation, fluctuation may readily be noted both on the outer 

 and inner surfaces of the joint. The exudate is sometimes so abundant 

 and distension so great that the straight ligaments, the neighbouring 

 bony prominences, and the ends of the tendons are buried in the liquid 

 swelling. 



Lameness, which is at first marked, often diminishes with exercise. 

 The length of the step is lessened. 



