NAVICULARTHRITIS. 171 



through the articulating cartilage." This shews the cartilage was 

 in the preparatory condition for ulceration. 



When, on the other hand, navicularthritis steals on by degrees — 

 as is the usual mode of its attack — we have evidence sufficient 

 that inflammatory action has set in, and to this we are bound to 

 ascribe most, if not all, of the anormal phenomena which follow. 

 In this case, the probability is, that the injury giving rise to the 

 inflammation amounts to no more than a contusion or bruise of the 

 synovial membrane; and this is Mr. Turner's opinion: — "lam 

 thoroughly convinced," says he, ''that this complaint (navicular- 

 thritis) at its commencement, is neither more nor less than a bruise 

 of the synovial membrane lining the joint." 



Brauell tells us that the commencement of the disease is usually 

 marked by " either inflammation of the bursal membrane only, or 

 of that and the navicular. The superior portion of the bursa which 

 unites with the superior border of the navicular bone, and is con- 

 tiguous to the tendon, presents upon its internal surface a blush of 

 redness, accompanied at times with slight tumefaction. The por- 

 tion which covers the trochlear cartilage, as well as the anterior 

 surface of the tendon, has lost its pearly whiteness, and taken on 

 a safl'ron hue. And the bursa itself is frequently thickened. The 

 fluid contained within the bursa is of a reddish hue. The vessels 

 passing underneath the navicular are often found injected; and 

 the flexor tendon at its insertion often has the appearance of 

 having been compressed at its sides : its anterior surface looking 

 wrinkled." — '' When the navicular bone is inflamed it is red and 

 strongly injected. The vessels traversing it are dilated. But when 

 macerated, it is found to have decreased in weight — its texture to 

 have become more porous ; occasionally the bone having a pufly 

 appearance." 



Inflammation having set in, what follows] — Remem- 

 bering that the inflamed tissue is a secreting structure, and being 

 acquainted by observation with what happens in like circum- 

 stances in other joints, we are prepared to meet with 



Defective secretion of synovia. The late Professor Cole- 

 man had observed this change ; and the fact has since received 

 ample confirmation at the hands of Mr. Turner, whose words are — « 



