398 



rmST, MACDOXALD, MOSS, AND SKOOG 



Fig. 5D. Photomicrograph showing dii area of devitahzed bone in the 

 center of the cortex of the tibia in severe osteoporosis. The lacunae are en- 

 kirged everywhere and the osteocytes are either pvknotic, fragmented, or 

 absent. The thin hne inchcated by the arrow represents a rapidly deposited 

 metachromatic-staining cement substance on the outer wall of a resorption 

 cavity; this is the reversal line that marks the beginning of construction of a 

 new osteon. ( X approx. 400.) 



Case No. 8 



M. R., a retired school teacher, 71 )'ears of age, had severe back- 

 aches, pam in both lower extremities, and was unable to walk with- 

 out the aid of two canes. At the age of 68, while lifting an emptv 

 bookcase weighing less than 25 pounds, she incurred a compression 

 fracture of the 12th dorsal vertebra. One month later, three addi- 

 tional vertebrae, the 9th and 10th dorsal and the 1st lumbar vertebra, 

 collapsed following a trixial injurw She lest 6 cm in height and 25 

 pounds in weight in a period of 6 months (Figs. 6A and 6B). The 

 treatment of the fractures consisted simply of bed rest and 5 mg 



