Paget disease of bone: Nursing

Paget disease of bone is a disorder in which there’s a lot of bone remodeling that happens in some regions of the bone. Typically, there’s excessive bone resorption followed by disorganized and excessive bone growth, leading to skeletal deformities, fragile bones, and potential fractures. Paget disease of bone can affect a single bone or several bones, and most often, it involves the skull, spine, pelvis, arms, and legs.

Now, let’s quickly review the physiology of bones.Normally, the surface of the bones is covered by a dense layer of connective tissue called the periosteum, and it's where the muscles, tendons, and ligaments are attached.

Beneath the periosteum, there’s a dense and tough external layer called compact bone or cortical bone composed of collagen and hydroxyapatite which contains calcium and phosphate.

In the center of the bone, there’s the medullary canal, a hollow space lined by a honeycomb- looking structure called the spongy or cancellous bone. The spaces in the spongy bone are occupied by the bone marrow, which is the site of blood cell production.

At first glance, a bone may appear inert and unchanging, but it’s actually a very dynamic tissue. In general, a bone is replaced with new cells every three to ten years in a process called bone remodeling, which has two steps: bone resorption, when specialized cells called osteoclasts break down bone, and bone formation, which is when another type of cells called osteoblasts form new bone.

The exact cause of Paget disease of bone is unclear, with some theories suggesting that it can get triggered by infections like the measles virus, and is linked to genetic mutations. Risk factors include being assigned male at birth, age over 40, family history of Paget disease, Caucasian race, or northern European descent.

The pathology of Paget disease has three phases, called lytic, mixed, and sclerotic phases. Phase one is the lytic phase, and that’s where osteoclasts increase in number and activity to aggressively demineralize the bone.