20 ON TPIE NAVICULAR DISEASE. 



navicular l)onc. When this adhesion, or morbid 

 insertion of the tendon into the bone, is present, 

 there is generally, exclusively of the loss of carti- 

 lage, a diminution also of the navicular bone itself, 

 leaving a hole in its centre formed by absorption. 



In the earlier stage of the complaint, there is a 

 deficiency of synovia, but not a total absence of it ; 

 the secreting or synovial membranes highly in- 

 flamed ; an absorption of part of the cartilage of the 

 inferior surface of the navicular bone, more parti- 

 cularly in the centre ; and a roughness of the cor- 

 responding surface of the tendon. At this crisis 

 there is only a slight adhesion of the tendon to the 

 bone. 



In very recent cases I have not found the tendon 

 adhering to the bone, but I have invariably perceived 

 a lesion or abrasion of a small portion of synovial 

 membrane from the tendon, and generally that part 

 of it which is opposed to the centre of the bone, 

 exhibiting small streaks or shreds in the tendon ; 

 whilst the cartilage covering the corresponding part 

 of the bone has appeared discoloured. 

 Thick strong This discasc more especially attacks that very 

 di*spos( mi\o na- foot wliicli wc are in the habit of calling a strong 



vicular lame- , i oi /« i i n i i 



ness. one, where the iibrcs of the horn are nrm and touo-h, 



the toe thick and round, the wall or quarters strong, 

 and high at the heels ; the bars strong and deeply 

 buried in the foot ; the sole thick and concave. 

 Such a foot is not so much disposed to a})proxima- 



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