MSK - Ageing Flashcards
What are the two main categories of metabolic bone disease?
- Disorders of Bone Remodelling
- Disorders of Mineralisation
What is osteoporosis?
Osteoporosis is disorder of bone quantity, not quality - decreased bone mass and bone mineral density
Results in…
Deterioration of microarchitecture
Compromised bone strength
Increased risk of fractures
What is paget’s disease? What the associated clinical features?
Characterised as abnormal localised bone remodelling
Primarily increased OC resorption - resulting in increased but disorganised bone formation
Polyostotic disease – multiple bones are diseased
2nd most common metabolic bone disease
Clinical features…
1. Enlarged skull
2. Bowing of long bones
3. Large joint OA
4. Fractures
5. Nerve compression (e.g. due to thickening of the skull) - Deafness
What is Paget’s sarcoma?
Pagets disease turns into a malignant bone cancer
Makes up less than 1% of Paget’s cases
Most commonly osteosarcoma
Osteo = osteoblastic differentiation and malignant osteoid production
Sarcoma = malignancy from mesenchymal cells
Metastatic disease has poor prognosis
Outline the pathogenesis behind paget’s disease.
Most cases are spontaneous but with a significant genetic component - appears to be a genetic predisposition, that requires an environmental trigger
Pathology - Abnormal osteoclasts/precursors
Greater in number, unusually large and hypersensitive to stimulation
3 phases which can co-exist in the same bone
1. Lytic – Intense osteoclastic resorption
2. Mixed – resorption and compensatory formation (OB activity)
3. Sclerotic – predominant osteoblastic formation
What investigations and treatments are used for paget’s disease?
What is osteopetrosis?
Summary of osteoporosis, paget’s disease and osteopetrosis.
What are the two disorders of mineralization?
Disorders of Mineralisation
1. Hyperparathyroidism
2. Vitamin D-related disorders (osteomalacia, rickets)
What is hyperparathyroidism?
What are the consequences of having elevated PTH?
All resulting in increased bone breakdown
How does hyperparathyroidism present itself clinically?
Symptoms and signs
‘Bones, stones, abdominal groans. Thrones and psychic moans’
Bones - arthiritis, osteoporosis, gout, pseudo-gout.
Stones - Kidney stones - elevated Ca2+
Abdominal groains - constipation, GI Ulcers and acute pancreatitis, polyuria
Psychic moans (most common presentation) - fatigue, depression, confusion
What are the treatments for hyperparathyroidism?
Depends on whether it is primary or secondary
Primary
Parathyroidectomy = 97% cure - surgical removal of gland/tumour
Secondary
Tackle the underlying cause
Vit D deficiency most common
Renal disease - complex
Recap what are the sources of Vitamin D, how is it metabolized and what effects does it have on the body (Calcium and Phosphate)?
What is rickets?
Rickets – disease of childhood
How does rickets appear clinically?
What are the treatments used for rickets?
What is Osteomalacia?
How does osteomalacia present itself clinically? What treatment is required?
- Bone and muscle pain
- Atypical fractures - ‘Looser zones’
- Femur/femoral neck fractures
- Proximal muscle weakness
- Fatigue
- Hip arthritis with ‘protrusio’ - head of the femur pushes into the acetabulum – left hand side
Treatment = Large doses of vitamin D
What does the epidemiology of osteoporosis look like?
How does bone mass/density change as we age?
- Increase in bone mass - Men – higher peak bone mass – more muscle mass – greater pull – greater bone density - peaks at late 20’s - Men start at a higher peak bone density relative to women
- Consolidation period
- Decline – age related bone loss – after the age of 40
Quicker drop off in females - drop in oestrogen after menopause which is protective - inhibits Rank-L
Eventually people’s bone density decreases to a point where it is below the fracture threshold – in terms of bone density – at this point their at a high risk of low energy fractures
How does bone mass/density change as we age?
- Increase in bone mass - Men – higher peak bone mass – more muscle mass – greater pull – greater bone density - peaks at late 20’s - Men start at a higher peak bone density relative to women
- Consolidation period
- Decline – age related bone loss – after the age of 40
Quicker drop off in females - drop in oestrogen after menopause which is protective - inhibits Rank-L
Eventually people’s bone density decreases to a point where it is below the fracture threshold – in terms of bone density – at this point their at a high risk of low energy fractures
What are insufficiency and fragility fractures?
Insufficiency - like a stress fracture -repeated loading
Fragility - normal force, abnromal bone - fracture
What is a common spinal fracture observed in older patients?
Forms a vicious cycle – compression – more forward lean – increased compression
Osteoporosis - risk factor
What is a common fracture observed in the arm in older patients?
Proximal Humerus Fracture
What is a common fracture seen in the forearm in older patients?
Wrist fractures - associated with displacement of wrist reltaive to radius
Most common MSK injury
17.5% of all fractures
3:1 female:male
Eponymous terms
Smith’s = volar extra-articular (forward)
Colles’ = dorsal extra-articular (backwards)
How do fractures in the pelvis normally present? How are they normally treated/managed?
Pelvis can be divided into multiple rings - usually have two fractures in a single ring structure
Conservative management - bedrest, NSAIDs, physio
What are the different form surgery used for hip fractures?
Important consideration - Blood supply of the femoral head – retinacular vessels – fractures that are before the neck, the vessels are not effected but if its higher up –> bone may lose blood supply – necrosis – replacement – usually hemi-arthroplasty
Intracapsular & extracapsular refer to the location of the fracture
What is an important consideration when deciding whether to fix or replace a fractured hip?
Blood supply of the femoral head – retinacular vessels – fractures that are located before the neck, the vessels are not effected
But if its higher up – bone may lose blood supply – necrosis – replacement – usually hemi-arthroplasty
What are atypical femor fractures?
Atypical femoral fracture is an uncommon complication of long-term use of bisphosphonates
Features…
1. Insufficiency fracture - No trauma
2. Subtrochanteric - within 5cm below lesser trochanter
3. mainly transverse
4. Involve lateral cortex
5. Endosteal or periosteal thickening
6. Cortical beaking - little bump
Why?
Osteoclast remodelling inhibited
Unable to heal micro-trauma
Goal - Aim to prevent complete fracture - Biphosphonate holiday and surgery (intramedullary nail)
What are the different components that make up hyaline cartilage?
How is hyaline cartilage structured?
When looking at the overarching arragnment of collagen fibres in hyaline cartilage, what do we observe?
Organization of fibers – loop structure
How does the healing of superficial and deep lacerations differ in hyaline cartilage?
Superficial laceration – low levels of healing + some cell proliferation – common in arthritis
How do the following factors change with age and in OA - Water content, elasticity/stiffness, chrondrocytes, proteoglycans and collagen?
How does bossman Gavin define OA and what are the primary & secondary causes?
What are the four cardinal signs of OA on a radiograph?
What are the defining features that characterize OA
Missing from diagram - primarily effects larger joints
How is OA normally diagnosed?
What are the treatment options for OA?
Conservative should be considered first…
- Patient education
- Physiotherapy and exercise
- Lifestyle changes and adaptations
a) Lose weight
b) Simple Analgesia
c) Walking aids
If conservative means are exhausted or in the presence of disabling symptoms, joint replacement should be considered
Are the outcomes for joint athroplasty normally succesful?
What is the underlying pathophysiology behind RA?
Increased levels of protein citrullination (arginine converted to citruline) - these modified protein are immunogenic, in turn and triggering an autoimmune response
Results in a T-cell mediated immune reponse
- B-cells receive antigen - processed
- Presents antigen to T-cell
- T-cell activates presenting B-cell
- B-cell population amplify and produce auto-antibodies (RF and anti-CCP)
RF - antibody that recongizes the Fc portion of IgG antibodies
Anti-CCP - antibodies that target citrulinated proteins/peptides
How does RA present itself clinically?
Deformities also possible but less common
What are the extra-articular and systemic symptoms in RA patients?
Average of 10 year reduction in life expectancy
How does RA differ to OA in terms of their presentation and symtpoms?
RA - smaller joints progressing to larger ones
OA - primarily effects larger joints
How is RA diagnosed?
Basically perform a blood test looking at levels of RF and anti-CCP (Better sensitivity - present in 96-98% of RA patients)
Possibility of also performing an x-ray
What does the X-ray of RA patients look like?
Erosive arthritis
- Joint space narrowing
- Subchondral erosions
- “Gull-wing” appearance
- Joint ankylosis - stiff joints
- Subluxations/dislocations - less common
Apart from DMARDs, what other ways is RA managed?
How does septic arthritis normally present?
What investigations should be conducted on patients that are suspected of having septic arthritis?
