EFFECTS ON THE SKELETON I 53 



In a typical section through an area of enchondral ossification (e.g., a 

 costochondral joint), as shown by Figs. 55-57, the structure of the cartilage 

 appears abnormal. The zone of proliferation is usually increased in thickness, 

 and the normally columnar arrangement of the cells becomes very irregular. 

 The provisional calcification of the cartilage matrix occurs. But since this 

 zone is not (as normally) invaded and replaced by the osteogenic tissue from the 

 marrow, the calcified trabeculae do not become covered with bone, but form a 

 widened and weak layer which easily fractures. The consequent hemorrhages, 

 with partial organization and resorption from the adjacent marrow and 

 periosteum, result in the very irregular and variable structure of this swollen 

 area ("Trummerfeld" of Fraenkel). 



Adjacent to this "Trummerfeld," the bone marrow presents a fibroreticular 

 structure with a gelatinous ground substance and few marrow cells 

 ("Gerustmark" of Schodel and Nauwerk). Scattered through the marrow 

 of this region multiple hemorrhages frequently occur. The marrow in the 

 remainder of the shaft is more nearly normal. The interspersed bony trabeculae 

 appear variably thinned, due to failure of bony apposition, combined with con- 

 tinued resorption. Schmorl ('07) opposed Looser's theory that the rachitic 

 bone changes are secondary to the marrow hemorrhages. 



Osteogenesis is also retarded or entirely inhibited in the periosteum, with 

 primary atrophy of the osteoblasts. Resorption continues, however, although 

 the osteoclasts are not abnormal in number. The entire bone, both cortex and 

 spongiosa, therefore becomes progressively osteoporotic. The bony tissue is 

 normally calcified, but great reduced in amount. Bahrdt and Edelstein C13) 

 and others have found that the fat content of the bones in infantile scurvy may 

 be nearly unchanged, although the calcium and phosphorus content is greatly 

 reduced. 



The histological changes in the skeleton of scorbutic adults appear very 

 similar to those in children, excepting the intensive changes in the cartilage at 

 the junction with the marrow. It may be noted that in children a coincidence 

 of rickets and scurvy is not infrequent, as in the case described by Ingier ('13). 

 Such complications, as also the changes during recovery from scurvy, may pro- 

 duce very puzzling structural conditions. 



Experimental Scurvy. — Bartenstein ('05), Frolich ('12), and others found 

 that young guinea pigs fed on raw or sterilized milk diet develop skeletal lesions 

 (including microscopic) which have a remarkable similarity to those of infantile 

 scurvy, excepting the absence of hemorrhagic tendency. Lipschiitz ('10) 

 obtained similar results in puppies fed a phosphorus-poor diet of rice and egg 

 albumin, supplemented by salt mixtures. The addition of casein, lecithin, 

 nucleins and phosphates gave normal structure in controls. Schmorl ('13) 

 obtained in puppies on phosphorus-poor diet skeletal lesions even more closely 

 resembling human scurvy, with occasional small hemorrhages in the subchondral 

 zone. The more typical hemorrhagic condition was absent, however, and 

 Schmorl concluded that the disorder is not identical with human scurvy. 



A new epoch in experimental scurvy began with the work of Hoist and 

 Frolich ('07, '12). They found that by means of various diets (cereals or bread) 



