Histologic Classifications of Bone Disease Associated with Chronic Kidney Disease

PTH receptors, vitamin D receptors, and calcium-sensing receptors are all present in osteoblasts. Osteoblast-mediated bone formation is coupled to osteoclast-mediated bone resorption through osteoblastic paracrine pathways. The circulating level of PTH is the primary determinant of bone turnover in CKD and is a major determinant of the type of bone disease present. The specific types of histologic changes also depend on the age of the patient, the duration and cause of kidney failure, the type of dialysis therapy used, the presence of acidosis, vitamin D status, accumulation of metals such as aluminum, and other conditions affecting mineralization of the extracellular matrix.


Bone disease associated with CKD (Fig. 58-2) has traditionally been classified histologically according to the degrees of abnormal bone turnover and impaired mineralization of the extracellular matrix. These histologic changes in bone have been best studied in dialysis patients. The current categories are as follows:

	1.	Secondary hyperparathyroidism or high-turnover bone disease or osteitis fibrosa cystica
	2.	Mixed uremic bone disease (a mixture of high-turnover bone disease and osteomalacia)
	3.	Osteomalacia (defective mineralization)
	4.	Adynamic bone disease (decreased rates of bone formation without a mineralization defect)