822 TREATMENT OF SYNOVIAL DISTENSIONS. 



opening by the actual cautery is less dangerous than by the knife, 

 but the effect is not always reliable. When the exact degree of 

 inflammation necessary to prevent after-secretion of fluid is pro- 

 duced, a cure may result, but this degree is very difficult — indeed, 

 usually impossible — to secure at will. 



The same criticism applies to drainage of synovial sacs. This 

 treatment consists in puncturing the distension at the highest point, 

 passing a director and making a counter-opening at the lowest point 

 inserting a drainage-tube, and irrigating the sac with 1 in i,000 

 sublimate solution. Active inflammation follows and persists for 

 three or four weeks. In favourable cases, the endothelial lining 

 of the sac, though at first replaced by granulations, is said to be 

 restored. The treatment has hitherto been confined to enlargements 

 of the extensor sheaths in front of the knee and fetlock. 



To sum up : enlarged synovial cavities should at first be treated 

 by rest, cold applications, massage and compression. If they cause 

 lameness a blister can be tried ; in the event of this failing the parts 

 are fired in lines or points, or the swelling may be punctured with 

 the cautery and the contents evacuated, but only with full antiseptic 

 precautions. For enlargements of old standing which resist other 

 forms of treatment and cause permanent lameness neurectomy may 

 be performed. 



Frequently in hunters and steeple-chase horses, occasionally 

 in others, tendon sheaths are punctured by thorns, or opened by 

 wire, nails, splinters, &c. Acute synovitis, often complicated by 

 suppuration, follows, and a very serious wound results. Under 

 treatment usually the wound heals, leaving considerable permanent 

 distension or thickening of the sheath. Sometimes healing is 

 retarded or prevented by the presence of a foreign body, which may 

 be difficult to discover or remove, or the wound may close and after 

 an interval further swelling and pus formation occur near the seat 

 of the primary injury. In most cases counter-openings have to be 

 made for the free discharge of exudate or pus and to permit of thorough 

 disinfection of the sheath. Sometimes thorns penetrate the sheaths 

 and remain permanently without inducing important symptoms. 

 The sheath may be somewhat distended and painful, but the irritation 

 gradually subsides and the thorn may only be revealed, months or 

 years later, by post-mortem examination. Thorns — sometimes as 

 many as forty — have been found lodged in sheaths and beneath 

 the aponeuroses of the limbs of horses which during life exhibited 

 no symptoms of lameness attributable to this cause. 



