Bone disorders - Osteoporosis, Osteomalacia, Multiple Myeloma, Bone Mets, Paget's Disease

Question 1

Osteoporosis
-pathophysiology
-risk factors
-presentation
-investigations
-management

Answer 1

Increased osteoclast bone breakdown + decreased osteoblast bone formation => decreased mineral density

Age
Prolonged CS, alcohol use
Hyperthyroid, high PTH
Immobilsiation

Asymptomatic until fragility fractures occur
-vertebral compression
-NOF, Colles

FRAX or QFracture - 10 year risk of fragility fracture

DEXA - assess bone density
T score
-1+ normal
-1 to -2.5 osteopenia
U-2.5 osteoporosis => TREAT
Z score - adjusted for age gender ethnic

Xray - asymptomatic fractures

Other bloods to exclude secondary causes
-FBC, U&E, LFT, TFT, VitD, T, PRL

Lifestyle
-falls risk assessment, FRAX tool
-weight bearing, muscle strengthening exercises
-Ca, Vit D supplementation

1st line - PO alendronate once a week
-taken before breakfast with water, sitting upright for 30mins
-reduce risk of esophagitis
2nd line - risendronate
IV zolendronate, denosumab consdered
Denosumab

Question 2

Osteoporosis
-assessing risk, when to do this
-available tool and interpretation

Answer 2

Women 65+
Men 75+

Younger if
-past fragility #, falls
-current/past frequent PO/systemic CS
-FHx H#
-other causes of 2ndary osteoporosis
-Underweight BMI
-smoking, alcohol intake 14U+

FRAX
-green - reassure, lifestyle
-amber or red - DEXA

DEXA - T score (based on young reference population)
-> -1 = normal
- -1 to -2.5 = osteopenia
- < -2.5 = osteoporosis

REASSESS FRAX AFTER 5 YEARS

Question 3

Management of patients after a fragility fracture

Answer 3

75+ - assumed to have osteoporosis
Alendronate without DEXA

U75 - DEXA to confirm osteoporosis
-reassess with FRAX

Question 4

Management of GC induced osteoporosis
-when does risk increase
-how do we manage

Answer 4

Pred 7.5mg/day for 3 months+
If steroid use likely to last 3 months+

65+ => bisphosphonates, Ca, VitD
GENERALLY GIVE BISPHOSPHONATES REGARDLESS OF DEXA

If U65 => DEXA
If T score 0+ => reassure
If T score between 0 and -1.5 => repeat in 3 years
-if T score U-1.5 => offer bone protection

Question 5

Osteomalacia
-pathophysiology
-risk factors
-presentation

Answer 5

Low VitD => softening of bones

VitD uptake low - lack of sunlight/diet/malabsorption
-coeliac, liver disease, drug induced
VitD activation - CKD

Bone pain
Muscle tenderness
Proximal myopathy => waddling gait
Fractures

Low VitD, Ca, PO4
High PTH => High ALP
Xray - translucent bands

VitD supplementation
Ca supplementation if dietary inadequate

Question 6

Multiple myeloma
-pathophysiology
-risk factors
-presentation

Answer 6

Genetic mutation - Plasma cell proliferation

60-70s

CRABBI
Calcium => hypercalcemia
-constipation, nausea, anorexia, confusion
Renal damage from light chain deposition
-dehydration, thirst
Anemia - BM crowding suppresses RBC formation
-fatigue, pallor
Bleeding - BM crowding suppresses platelet formation
-bruising, bleeding
Bones - plasma cell infiltration, increased osteoclast activity
-pain, pathological fractures
Infection - reduced no of normal ABs

Question 7

Myeloma
-referral criteria

Answer 7

Offer
60+ AND persistent bone pain (back, unexplained fracture)
=> FBC, Ca, plasma viscosity/ESR

Offer within 48hrs (v urgent)
60+ AND highCa, lowWCC with presentation consistent with myeloma
=> protein electrophoresis, Bence-Jones protein urine test

REFER 2WW if results of protein electrophoresis/Bence Jones protein urine suggest myeloma

Question 8

Myeloma
-investigations

Answer 8

Bloods
-FBC - anemia
-U&E - renal failure
-Bone profile - hypercalcemia
-Peripheral blood film - rouleaux

Protein electrophoresis
-serum - [high IgA/IgG monoclonal AB]
-urine - Bence Jones protein

BM aspiration - confirm diagnosis if plasma cell no v high

Whole body MRI over skeletal survey
-raindrop skull

Question 9

Myeloma
-diagnosis

Answer 9

1 major criteria or 3 minor criteria

Major
-High plasma cells on biopsy
-30% of plasma cells in BM sample
-High M protein in serum/urine

Minor
-10-30% plasma cells in BM
-small elevations in M protein in serum/urine
-osteolytic lesions
-low AB levels in blood (not cancer cells)

Question 10

Myeloma
-management

Answer 10

Treatment aims to control symptoms, reduce complications, prolong survival

Induction therapy
-targeted drugs
-chemo
-steroids

Autologous stem cell transplants
-remove own stem cells before chemo
-stem cells reintroduced after chemo
Only used for younger, healthier individuals who are suitable and strong enough to cope with chemo

Complication management
Pain - WHO pain ladder
Pathological fractures - IV zolendronate
Infection - annual flu vaccine, Ig replacement therapy
VTE prophylaxis
Fatigue - treat underlying cause, consider EPO analogue

Question 11

Paget’s disease
-pathophysiology
-risk factors
-presentation
-investigations

Answer 11

Disorder of bone remodelling starting with excess bone breakdown followed by excess bone formation

Older men
FHx

Often asymptomatic
-bone pain (pelvis, lumbar, femur)
-tibia bowing, skull bossing

High ALP
Normal Ca, PO4
Xray - osteolysis , thick skull vault
Bone scintigraphy

Treat if - bone pain, skull/long bone deformity, #, periarticular Paget
-PO risendronate or IV zolendronate

Question 12

Bone mets
-most common tumours causing mets
-most common met sites
-presentation
-investigations
-management

Answer 12

PROSTATE
Breast
Lung

SPINE
Pelvis
Ribs
Skull
Long bone

Pathological #
High Ca, ALP

Radiotherapy
Prophylactic fixation and analgesia

Question 13

Management of DEXA confirmed osteoporosis

Answer 13

Ca, VitD given unless adequate intake and VitD replete

Bisphosphonates
1st line - alendronate
Alt - risendronate

If bisphonates not tolerated
-strontium ranelate
-raloxifene
-denosumab
-teriparitide

Question 14

Osteoporotic fractures
-most common locations and presentation
-risk factors
-investigations
-management

Answer 14

Spine - acute back pain
But can be asymptomatic

Older age
Hx falls
PHx fragility #
FHx hip #
Predisposing factors
-prolonged GC
-hyperthryoidism
-Cushings
-low BMI
-smoking
-high alcohol intake

Localised tenderness on palpation of fracture site
Xray
-loss of height
-kyphosis

Post menopausal or 50+ male with vertebral fracture => PO bisphosphonate
Hips fracture => PO bisphosphonates
-BMD measured for baseline

Question 15

Open fractures management

Answer 15

Neurovascular assessment
Locate any bleeds
Examine extent of injury
Medical photography
Cover wound
IV ABx

Early debridemenet in theatre
Irrigate with saline
Stabilise fracture
External fixation until wound heals