Metabolic bone disease

Metabolic Bone Diseases

• Presenter: Prof. Tim Helliwell

• Audience: Year 3 B.D.S.

Key Topics:

1. Normal Bone Remodelling: Co-ordinated 3-4 month cycle involving osteoclast activation, bone resorption, formation of new bone matrix, and mineralization.

2. Bone Formation Control: Triggered by physical factors sensed by osteocytes; hormones like PTH and Vitamin D play critical roles in calcium metabolism and bone health.

3. Hyperparathyroidism:

   • Primary: Often asymptomatic, characterized by elevated calcium and low phosphate; severe cases show bone pain and fractures.

   • Secondary: Adaptive changes due to hypocalcemia (e.g. renal failure).

   • Tertiary: Autonomous nodules after chronic secondary hyperparathyroidism.

4. Paget's Disease:

   • Incidence: 3% among those over 40, possibly linked to viral infections.

   • Presents with bone deformities and may cause fractures and osteosarcoma in rare cases.

5. Osteoporosis:

   • Defined by reduced trabecular bone mass; common in postmenopausal women leading to fractures.

   • Diagnosis through imaging and treatment involves hormone therapy, exercise, and medication to enhance bone density.

6. Osteomalacia:

   • Resulting from defective mineralization leading to weak bones; often due to Vitamin D deficiencies.

   • Clinical presentations include bone pain and deformities, with varying degrees of altered bone density visible on X-rays.