Metabolic Bone diseases

Question 1

What is Paget’s disease of bone?

Answer 1

Localised increased bone turnover, affecting long bones and skull.
Bone becomes disorganised, more vascular and deformed (high risk of break)

Question 2

Presentation of Paget’s disease of bone?

Answer 2

Deep seated pulsing pain unchanged by exercise (due to increased vascularity)
Unilateral bone deformity or fracture
Excess heat over bone
Neurological signs (if skull affected) cranial or spinal nerve compression, deafness, headache, weakened limbs

Question 3

Risk Factors for Paget’s disease of bone?

Answer 3

Genetic link (SQSTMI)
Males more than females
Chronic viral infection - esp. MMR

Question 4

Investigation of Paget’s disease of bone?

Answer 4

Isolated elevation of serum alkaline phosphatase

X-ray and triple phase isotope bone scan

Question 5

Treatment for Paget’s disease of bone?

Lifestyle, medical and surgical

Answer 5

Lifestyle: fall prevention, regular exercise, Dietary calcium and Vitamin D
Medical: IV or oral Bisphosphonates (zoledronic acid)
Surgical Fracture fix, Joint replacement, deformed bone realignment, relieve compressed nerves

Question 6

Differences between Rickets and Osteomalacia?

Answer 6

Rickets: skeletal disorder due to lack of Vitamin D, Calcium or phosphate in a growing child; leads softened bones
Osteomalacia: they same but seen in adults (epiphyseal lines are fused) and bones soften to a lesser extent

Question 7

Symptoms of Rickets in a child?

Answer 7

Bone pain
Skeletal deformities (bow legs, thickened ankles, wrists and knees)
Fragile bones (fractures)
Dental problems
Poor development + reduced growth
Macrocephaly (front fontanelle late to close)
Seizures (hypocalcaemia)

Question 8

Symptoms of Osteomalacia?

Answer 8

• Muscle weakness (waddling, slow walking),
• Muscle dysfunction
• Fragile bones (fracture NO DEFORMITY)
• Joint pain
• Microfractures in cortex (pepperpot skull and ends of long bones)

Question 9

Risk factors for Rickets/Osteomalacia?

Answer 9

Lack of dietary Calcium/Vit. D (no sunlight, dark skin)
Premature/solely breastfed babies
Genetic kidney/liver disorders
Malabsorption (gastrectomy, coeliac, IBD)
Phenytoin (anti-seizure medication)

Question 10

Investigations of Rickets/Osteomalacia?

Answer 10

Bloods and Urine for calcium, phosphate, vit D levels

X-ray (micro/fractures), DEXA scan

Question 11

Treatment for Rickets/Osteomalacia?

Answer 11

Surgical realignment (rickets)
Sun exposure, dietitian (calcium, vitamin D)

Question 12

What is Osteogenesis Imperfecta?

Answer 12

Genetic: disorder of Type 1 collagen: Fragile bones

- varies e.g. death in utero or diagnosis after osteoporosis in 40s

Question 13

Types of Osteogenesis Imperfecta?

Answer 13

Type 1; Milder, childhood walking presentation -less collagen production
Type 2; death before 1 y/o
Type 3; Progressive deformations, severe bone dysplasia, poor growth, normal lifespan severely disabled -low quality collagen
Type 4; poor quality collagen

Question 14

Symptoms/signs of Osteogenesis Imperfecta?

Answer 14

Low energy fractures, bone deformation, growth deficiency 
Defective tooth formation (dentigenesis imperfecta); dentine feels pain, collagen beneath enamel (T1 and 4) 
Triangular face (T3) 
Hearing loss, Blue sclera (T1) Scoliosis, Barrel chest, Hypermobility, Easy bruising (thin blood vessels), Joint or bone pain

Question 15

Investigations for Osteogenesis Imperfecta?

Answer 15

Family history, DEXA scan, X-ray

Question 16

Treatment for Osteogenesis Imperfecta?

Answer 16

Surgical fracture treatment, realignment surgery (scoliosis, long bones)
IV Bisphosphonates, Vitamin D supplements, no impact sports, can’t be jostled

Question 17

What is osteoporosis?

Answer 17

Metabolic Bone disease:

reduced bone mass and density - low trauma fracture risk

Question 18

Presentation of Osteoporosis?

Answer 18

Female over 50

Back pain, Height loss, Stooped, low posture, Low trauma fracture

Question 19

Risk Factors for Osteoporosis?

Answer 19

• Age, Female, Previous fractures
• Endocrine: thyrotoxicosis, hypo/hyperparathyroidism, Cushing’s, hyperprolactinaemia, hypopituitarism, early menopause
• Rheumatoid disorders - STEROIDS,
• PPIs, Warfarin

Question 20

Investigations for Osteoporosis?

Answer 20

Q-Fracture (30-85)
FRAX (>40),  score 10% or more needs intervention
DEXA scan 
-1 = osteopenic
< -2.5 = osteoporosis

Question 21

Medical treatment for Osteoporosis and associated fractures?

Answer 21

Oral bisphosphonates - SE later
SERMs (raloxifene)
Denosumab (RANK ligand -can be used in pts with poor renal function)
HRT, Vitamin D, calcium supplements, Parathyroid hormone injections

Question 22

How do bisphosphonates work?

Answer 22

Poison osteoclasts - leaving behind the bone previously ingested

Question 23

Problems with bisphosphonates for osteoporosis?

Answer 23

Must be taken with lots of water and lie down after.
Needs adequate renal function, affects teeth.
Must take 1-2 year drug holiday after 10 years due to inflammatory effects.
Osteonecrosis of jaw
Atypical femoral shaft fracture (Asians)

Question 24

Non-medical treatment for Osteoporosis?

Answer 24

Treat risk factor conditions, fall prevention strategies