Session 11 - Ageing in the MSK Flashcards
What is sarcopenia?
-Loss of muscle mass due to loss of muscle fibres and reduced muscle cross sectional area
What happens to bone with age?
-The bone mineral density decreases
What are the consequences of sarcopenia?
- Loss of muscle strength and endurance
- Increased fall risk
- Increased fracture risk
- Reduction in ability to perform movements
When does bone mineral begin to decline?
-30 years
What promotes the loss of bone in addition to ageing?
- Low reproductive hormone levels
- Poor calcium and/or vitamin D,
- Inactivity
- Endocrine or gastrointestinal pathologies
What happens to the bone architecture with age?
-The trabecular network changes resulting in a irregular, weaker architecture = bone having decreased strength
What is the result of sarcopenia?
-Loss of muscle mass= loss of contractility
=Loss of neuronal innervation
Why do the elderly have an increased fall risk resulting in fracture?
- Decreased mobility
- MSK-related changes in posture and gait
- Neuro-related gait and proprioception changes
What are the three most common clinical consequences to bone of ageing?
- Osteoporosis
- Fractures
- Osteoarthritis
What is osteoporosis?
-A skeletal bone disease characterised by a low bone mass, with deterioration of micro-architecture causing increased bone fragility and susceptibility to fractures
What is a DEXA scan?
-Dual Energy Xray Absorptiometry scan used to assess bone mineral density
List some risk factors for osteoporosis
- Increasing age
- Early menopause
- Caucasian/Asian
- Previous fragility fracture
- Low BMI (under 19)
- Lifestyle (smoking, diet)
What is the pathophysiology of osteoporosis?
-Increased osteoclastic activity (Type 1)
or
-Attenuated osteoblastic activity (type 2)
What is type 1 osteoporosis associated with?
-Oestrogen withdrawal
What is type 2 osteoporosis related to?
-Age/Ca2+ deficiency, hyperparathyroidism
How do bisphosphonates help prevent osteoporosis?
They are anti-resorptive agents which inhibit osteoclastic activity and thus decrease bone turnover
How do bisphosphonates work?
- The bisphosphonates are taken up by the osteoclasts and inhibit the mevanolate pathway responsible for the activation of small GTPases which cause membrane ruffling
- Without membrane ruffling, the osteoclasts cannot sit on the lining of bone and resorb it
How many hip fractures per year in the UK?
-Approx 80,000
Why is there a risk of avascular necrosis with intracapsular NOF fractures?
-The medial circumflex femoral artery forms retinacular anastamoses around the femur head and is disrupted during the fracture leavinf a relatively scarce blood supply and avascular necrosis ensues
What are the morbidities associated with hip fractures?
- PE/DVT
- Pressure sores
- Chest infections/UTI
What is osteoarthritis?
-A disorder of synovial joints that is characterised by focal areas of damage to the articular cartilage and undergoes remodelling of the underlying bone with the formation of osteophytes
What is the prevalence of symptomatic OA in the UK?
-8.5 million people
What are the clinical features of OA?
- Pain
- Stiffness
- Deformity
- Joint swelling
What are the radiological features of OA?
- Decreased joint space
- Osteophytes
- Sclerosis
- Bone cysts
Name some non-operative treatments of OA
- Weightloss
- Exercise/physiotherapy
- Analgesia/NSAIDs
- Joint injection
What are the operative treatments of OA?
- Atheroscopy
- Osteotomy (Spreads the weight load)
- Arthrodesis (fusion of bones across a joint space which eliminates movement)
- Arthroplasty (Surgical refashioning of a joint)
What are the components of a total hip replacement?
- Acetabular component
- Femoral head and femoral stem
What are possible local complications of hip replacements?
- Leg length inequality
- Dislocation
- Infection
- Loosening
- Neurovascular damage
What are the possible systemic complications of THR?
- UTI/chest infections
- Clinical DVT
- Non-fatal PE
- Fatal PE
What MSK structures become affected by age?
- Bone
- Cartilage
- Fibrous tissue (ligaments, tendons etc)
- Skeletal muscle
- Fat
