Lecture 17 Metabolic Bone Disease

Question 1

What is the function of osteoclasts

Answer 1

Bone resorption

Question 2

What is the function of osteblasts

Answer 2

Bone formation

Question 3

What is Paget’s Disease

Answer 3

Increased bone resorption followed by increased bone formation

Question 4

What are the symptoms of Paget’s disease

Answer 4

• Presents >40 years
• Bone pain
• Occasionally bone deformity, excessive heat over the Pagetic bone
• Neurological complications such as nerve deafness

Question 5

What are the presentation of Paget’s disease

Answer 5

• Isolated elevation of serum alkaline phosphatase
• Bone pain and local heat
• Bone deformity or fracture
• Hearing loss
• Rarely the development of osteosarcoma in affected bone

Question 6

What is the treatment of Paget’s Disease

Answer 6

• No evidence to treat asymptomatic Paget’s unless in skull or in area requiring surgical intervention.
• Do not treat based on a raised alkaline phosphatase alone
• Intravenous Bisphosphonate therapy-One off zoledronic acid infusion

Question 7

What are the causes of Ricketts and Osteomalacia?

Answer 7

Severe nutritional Vitamin D deficiency or calcium deficiency
Osteomalacia in the adult when the epiphyseal lines are closed

Question 8

What is Osteomalacia

Answer 8

Softening of bones caused by impaired bone metabolism primarily due to inadequate levels of available phosphate, calcium and vitamin D

Question 9

What are the symptoms of Osteomalacia

Answer 9

Bone pain, muscle weakness, increased falls risk

Question 10

What is osteogenesis imperfects?

Answer 10

Genetic disorder of connectivity tissue characterised by fragile bones from mild trauma

Question 11

Name the 4 most common Type 1 collagen of Osteogenesis Imperfects

Answer 11

Type 1: milder form
Type 2: lethal by age 1
Type 3: progressive reforming with severe bone dysplasia and poor growth
Type 4: similar to type 1 but more severe

Question 12

Name other clinical features of defects in Osteogenesis Imperfects

Answer 12

Growth deficiency
Defective tooth formation
Hearing loss
Blue sclera
Scoliosis/Barrel Chest
Ligamentous laxity
Easy bruising

Question 13

What is the management of Osteogenesis Imperfects

Answer 13

• Surgical - to treat fractures
• Medical - to prevent fracture Intravenous Bisphosphonates
• Social-educational and social adaptions
• Genetic - genetic counselling for parents and next generation

Question 14

What is Osteoporosis

Answer 14

Metabolic bone disease characterised by low bone mass and micro architectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk

Question 15

Name the endocrine causes of osteoporosis

Answer 15

• Thyrotoxicosis
• Hyper and Hypoparathyroidim
• Cushings
• Hyperprolactinaemia
• Hypopituitarism
• Low sex hormone levels

Question 16

Name the rheumatic cause of osteoporosis

Answer 16

RA, ankylosing spondylitis, polymyalgia rheumatica

Question 17

Name the gastroenterological causes of osteoporosis

Answer 17

• Inflammatory diseases: UC and crohns
• Liver diseases: PBC, CAH, Alcoholic cirrhosis, Viral cirrhosis (Hep C)
• Malabsorption: Cystic Fibrosis, chronic pancreatitis, coeliac disease, whipples disease, short gut syndromes and ischaemic bowel

Question 18

Name some medications which cause osteoporosis

Answer 18

• Steroids
• PPI
• Enzyme inducting antiepileptic medications
• Aromatase inhibitors
• GnRH inhibitors
• Warfarin

Question 19

Name medications that help prevent osteoporotic fractures

Answer 19

HRT, SERM (Selective oEstrogen Receptor Modulator-Raloxifene), Bisphosphates, Denosumab

Question 20

What are the side effects of Denosumab

Answer 20

• Allergy/rash
• Symptomatic hypocalcaemia if given when vitamin D deplete
• ?ONJ- Osteonecrosis of the jaw (ONJ) is a severe bone disease (osteonecrosis) that affects the jaws (the maxilla and the mandible)
• ? Atypical femoral shaft fractures