SPLINTS. 857 



of the disease. Whilst on the outside the unciform rests partly 

 on the outer small splint bone, partly on the metacarpal bone, on 

 the inside the trapezoid rests almost entirely on the inner small 

 splint bone. This explains why faulty action or unequal distribution 

 of pressure in the knee may throw an excessive load on the inner 

 small metacarpal and cause ruptures in the interosseous ligament 

 attaching the small to the large metacarpal. The fibrous union 

 between the bones in young animals explains the frequent occurrence 

 of splints during early life. In aged horses the disease seldom occurs. 



This explanation of Havemann's was generally viewed as correct, until 

 Dieckerhoff raised a doubt about it, and stated that the disease of the 

 periosteum was produced by the pull of the fascia of the fore-arm. He 

 describes splints so produced as " spontaneous," in contra-distinction to 

 those caused by blows, which he terms " traumatic." The lower insertion 

 of the fascia of the fore- arm is partly into the metacarpal bones, especially 

 the inner small metacarpal, partly into the subcutaneous connective tissue. 

 Ruptures of it, and especially of its point of insertion into the bone, are 

 said by Dieckerhoff to give rise to disease in the subfascial connective 

 tissue, which disease extends to the periosteum. The facts adduced by 

 Dieckerhoff in support of this modification of Havemann's view seem 

 insufficient, and by no means conclusive. There is much evidence in 

 support of Havemann's showing. The disease generally begins in the 

 interosseous ligament, between the small and large metacarpal bones, 

 whilst no disease process of any kind can be detected in the fascia. Nor 

 can oedematous swelling of the subcutis be regarded as an infallible sign 

 of the condition referred to, for it is scarcely ever absent in periostitis in 

 other positions. To this must be added that inflammation may also be 

 caused by violent tension on the other ligaments, which become attached 

 to the inner small metacarpal bone, and may lead to disease in the spot 

 in question. For prognosis and treatment, it is, of course, of little import- 

 ance which view one takes. 



Splints may be divided into two classes— those due to unequal 

 distribution of pressure, and those due to blows. The two kinds 

 admit of easy clinical distinction. The first is generally of a long 

 shape, and is found in the groove between the small and large meta- 

 carpals or on the small metacarpal alone ; not infrequently several 

 lie one above the other, having been formed simultaneously or soon 

 after one another. Those produced by blows are generally further 

 forward and on the large metacarpal, i.e., they appear in front of the 

 small metacarpal, are generally of a rounded shape, and are discrete. 

 Cicatrices or injuries of the skin cannot always be detected. 



Horses with bad action often strike themselves. The weight is 

 irregularly distributed in their joints, and therefore such animals 

 have a double disposition towards the production of splints. This 

 is particularly true of those which turn the toes either outwards 



