Fig. 102. Horizontal Section through the Dorsum of the Right 



Hand; Articulations. 



A horizontal section lias exposed to vieiu from the dorsal aspect all the arti- 

 culations ivhich lie between the forearm above and the Metacarpal bones below, 

 but those joints which do not lie in the plane of the section have been opened 

 independently, viz: a) Cuneiform — Pisiform, b) Trapezium — ist Metacarpal. 



The following Joint Cavities or combination of Joint Cavities are found 

 in the hand : — 



i) Joint between Radius, Scaphoid & Semilunar extending almost to the 

 Cuneiform but separated from the following joint by the Triangular 

 Articular Fibro-Cartilage, "the Radio-Carpal Articulation", the Wrist 

 Joint Proper. 



2) Joint between Head of Ulna, Radius and Inter-articular Fibro-Cartilage, 

 "the Inferior Radio-UInar Articulation". 



3) Joint between the Cuneiform and Pisiform Bones. 



4) Joint between the Trapezium and the ist Metacarpal Bone. 



5) Joint between tlie Unciform Bone and the bases of the 4th and 5th 

 Metacarpal Bones; this may communicate with the following (6). 



6) Combination of the joint cavities between the distal surfaces of the 

 Scaphoid, Semilunar and Cuneiform Bones, the proximal surface of the 

 Unciform Bone, all the articular surfaces of the Os Magnum and the 

 Trapezoid, the inner surface of the Trapezium and the bases of the 

 2nd and 3rd Metacarpal Bones. "Intercarpal and Carpo-Metacarpal 

 Articulation". 



The wide extension of No. 6 forms an important point in the spreading 

 of pathological processes. 



The Dorsal and Palmar ligaments of the Carpal Joints are very strong 

 so that extreme Dorsitlexion (e. g. as in a fall on the hand) is more likely to 

 result in a fracture of the lower end of the radius than in a rupture of these 

 ligaments. (Lecomte; cf. the behaviour of the malleoli, in particular the external 

 or fibular.) 



