252 



ARTICULATION. 



Fig. 111. 



ever, anatomists are by no means likely ever 

 to be unanimous, because of the difficulty or 

 impossibility of tracing by the ordinary me- 

 thods of dissection the synovial membrane 

 over the articular cartilages. The continuity of 

 this membrane over the cartilage was first 

 distinctly announced and described by Dr. 

 W. Hunter, in the paper to which we have 

 already referred in the Philosophical Trans- 

 actions : after him Soemm erring described it, 

 and still later Bichat, who insisted more par- 

 ticularly on its analogy with serous mem- 

 branes. Bichat's description has been followed 

 by Meckel, Beclard, and most of the anato- 

 mists of modern times; but its accuracy has 

 been called in question by Cruveilhier,* 

 Gordon,f Magendie,J Blandin, and more re- 

 cently by Gendrin|| and Velpeau.^F 



The advocates for the continuity of the syno- 

 vial membranes over the diarthrodial cartilages, 

 found their opinion on the following facts : 

 1 . Synovial membranes elsewhere, lining ten- 

 dinous sheaths or bursae mucosae, are distinctly 

 and obviously shut sacs. 2. We do not find 



* Observations sur les Cartilages diarthrodiaux. 

 Arch. Gen. de Med. torn. iv. p. 161. 



t Gordon says, " the continuation of the syno- 

 vial membranes over the surface of articulating 

 cartilages is, I am convinced from a number of ex- 

 periments, altogether an anatomical refinement." 

 System of Human Anatomy, p. 261 . 



$ Compend. of Physiology, by Milligan, p. 450. 



Additions a Bichat, par Beclard et Blaiidin, 

 p. 345. 



(I Hist. Anat. des Inflam. t. i. p. 60. 



II Anat. Chir. ed. 2de, t. i. p. 176. 



cartilage to present the smooth and polished 

 aspect exhibited by the articular surfaces, ex- 

 cepting where it is connected with synovial 

 membrane, as it evidently is to at least a cer- 

 tain extent in the moveable articulations. 3. If 

 by an oblique cut we raise a slice from an arti- 

 cular cartilage, and turn it back so as to rupture 

 it at its base, we shall find it still retained in 

 connexion with the rest of the cartilage by a 

 thin pellicle, which seems to have all the cha- 

 racters of synovial membrane. A similar mem- 

 brane may be seen by sawing a bone vertically 

 down to the cartilage, and then breaking the 

 cartilage by forcibly separating the segments. 



4. Some observers state that they have seen the 

 redness of inflammation affecting the synovial 

 membranes prolonged over the cartilage,* but 

 becoming gradually less marked towards the 

 centre (this, I must confess, I have never seen). 



5. Bands of adhesion are also said to have been 

 met with in some cases of chronic inflammation 

 of the synovial membrane, passing from the ar- 

 ticular surfaces, as well as from other parts of 

 the interior of the joint. 6. In that peculiar 

 disease of the synovial membrane described by 

 Brodie,the pulpy substance has been seen on the 

 articular cartilages, as well as on the menisci.f 



On the other hand, the opponents of this 

 opinion deny : 1, that the membrane demon- 

 strable by slicing the cartilage in the way above 

 described, is any thing else than a very thin 

 lamina of cartilage ; 2, they say that by even 

 the most successful injection the fluid cannot 

 be made to pass beyond the margin of the car- 

 tilage ; 3, they assert that inflammation always 

 stops abruptly at the circumference of the car- 

 tilage ; 4, and that if a synovial membrane did 

 exist on the free surface of the cartilage, there 

 would take place a continual exhalation of sy- 

 novia from the articular surface, contrary to what 

 was~found to be the case in an experiment tried 

 by Cruveilhier : synovia was freely exhaled from 

 the membrane lining the ligaments, and after 

 having been wiped off reappeared with rapidity ; 

 but not so over the articular cartilage, the sur- 

 face of which became quite dry. J 



Cruveilhier, however, relates a case which in 

 some degree invalidates his own conclusions ; 

 it was one in which fungous granulations sprang 

 from the articular surfaces of the femur and 

 tibia in the knee-joint, and by their adhesion 

 produced anchylosis of the joint : this fact Cru- 

 veilhier very candidly expresses his inability 



* I am uncertain whether the fourth case related 

 by Sir B. Brodie in the last edition of his work on 

 the joints, may not be regarded as affording an in- 

 stance of this. In the account of the post-mortem 

 examination it is said, " The synovial membrane 

 was everywhere of a red colour, as if stained by 

 the secretion," p. 15. Beclard, whose powers 

 and accuracy of observation few will be disposed 

 to question, speaks with the confidence of one who 

 had seen this extension of the vessels over the car- 

 tilage. Anat. Gen. p. 214. 



t Vide the 17th, 18th, 19th, 21st, and 22d cases 

 recorded in Sir B. Brodie's work. 



| Cruveilhier, loc cit. 



He confesses, " ma conviction n'est pas cepen- 

 dant pleine et enliere." 



