Skeletal Conditions, Signs, Causes And Differentials

Question 1

What is Paget’s disease?

AKA Paget’s disease of the bone

Answer 1

A common (11% of those >80) chronic bone disease, characterised by localised areas of excessive bone remodelling (metabolic hyperactivity).

The bones become larger, with the skull, spine, pelvis and long bones affected most frequently.

MOA: Strange multinucleate osteoclasts are present. Ostoclast activity increases and in order to compensate, osteoclast activity is dramatically increased in the lesions. This forms woven bone (not lamellar), which is weaker and prone to deformities and microfractures. The new bone is highly vascularised which in combo with the microfractures causes the pain of the disease.

Stages -

1. Multinucleate osteoclast activity peaks initially
2. Mixed phase; osteo- clast/blast activity increase
3. Chronic sclerotic phase; bone deposition outstrips bone resorption

Classifications:

• Monostotic = only one bone involved
• Polostotic = more than one bone involved

Question 2

What are the signs of Paget’s disease?

Answer 2

Most people are asymptomatic

Localised pain/tenderness

Increased local temperature (increased vascularity)

Increased bone size

Kyphosis

Bowing deformities

Decreased range of motion

Nerve impingement

Osteoarthritis

Fractures (risk is increased)