case 25- physiology 2 Flashcards
Nutritional frailty
Common in vulnerable older adults.
Sudden weight loss and loss of muscle mass and strength
Loss of physiological reserve
Medication side effects that affect nutritional status
Appetite changes Nausea Dry mouth Changes in taste/smell GI effects Glucose levels Organ system toicity
Decrease in calorific requirements in the elderly
Decreased body mass and decreased activity levels and decreased BMR reduce calorie requirements
Micro/macro requirements in the elderly
Requirement for micro/macronutrients doesn’t really change but absorption might be less efficient due to multimorbidity so might actually need more
Assessing nutritional status
Nutritional screening should be used to identify any individuals at risk of malnutrition
When should it be done- On admission and at regular intervals
In the community should be done in care homes on admission and monthly and annually if >75 and living at home
Assessing nutritional status
Nutritional screening should be used to identify any individuals at risk of malnutrition
When should it be done- On admission and at regular intervals
In the community should be done in care homes on admission and monthly and annually if >75 and living at home
Assessing nutritional status- methods
BMI Skin fold thickness - % body fat Body circumference Waist-hip ration MUST - malnutrition universal screening tool Functional assessment Biochemical tests
MUST
Find out if low, medium or high risk of malnutrition
Management after MUST - special diet? local policy, treat underlying condition - advice on food choices, eating/drinking
Record presence of obesity
Functional and Biochemical tests for malnutrition
Functional- Grip strength, overall muscle strength
Biochemical- Blood index, Anaemia, Total lymphocyte count, Serum protein
Clinical features of neck of femur fracture
Shortened
Abducted
Externally rotated
Flexed
Retrograde blood flow
Blood goes from peripheral areas back to heart 3 bones in body - head of femur - talus - scaphoid
More prone to avascular necrosis
NOF fracture classification
Intracapsular - degree of displacement
Extracapsular - number of parts and displacement
Open or closed
Orientation
Displaced and undisplaced fracture
Displaced- bone ends are out of normal alignement
Undisplaced- the bone is without angulation or separation
Haematomas in healing
Part of healthy process of healing - contains growth and healing factors
Not present in intracapsular fractures
Gardens classification of intracapsular ligaments
Based on degree of displacement of bony trabeculae
Relates to risk of vascular disruption and healing
Treatment determined by these factors
Purely based off AP views of pelvis
Different classifications in Gardens classification
A - incomplete, vagus impacted, non displaced
B - complete, non displaced
C - complete, partially displaced
D - complete, fully displaced
Pauwels classification of fracture
Angle of fracture line
More angle means more vertical, more shear force, less chance of healing
Classification of fracture based on location
Intracapsular
- subcapital (just below head)
- transcervical (neck of femur)
- base of neck
Extracapsular
- intertrochanteric
- subtrochanteric
Fracture fixation
Young age
Undisplayed/reducible
Extracapsular
Arthroplasty- replaced
Surgical repair or replacement of a joint
- elderly/poor bone quality
- displaced
- intracapsular
- presence of arthritis
Fixation devices
Dynamic hip screw
Cannulated screw
Intramedullary nail
Types of arthroplasty
Hemiarthroplasty - Austin Moore and Thompson
Total hip replacement
Fracture healing
Need a good blood supply
Mechanical stability
Can heal directly or indirectly
Direct healing
Bony fragments are fixed together with compression
No callus formation
Bone ends are joined and healed by osteoblast and osteoclast activity
Direct healing
Bony fragments are fixed together with compression
No callus formation
Bone ends are joined and healed by osteoblast and osteoclast activity
Indirect healing
More common
Involved in endochondral and intramembranous bone healing
Usually occurs with non operative fracture treatment, operative treatments where some motion occurs at the fracture site such as intramedullary nailing, external fixation and internal fixation of comminuted fractures
Stages of fracture healing
- haematoma formation
- fibrocartilaginous callus formation
- bony callus formation
- bone remodelling
Haematoma formation
1-7 days post fracutre
- fracture causes soft tissue damage, disruption of blood vessels in bone and separation of small bony fragments
- haematoma forms and periosteum ruptures partly
- cells migrate into fracture haematoma
- coagulation starts, fibrin fibres are form and stabilise haematoma
Soft callus formation
2-3 weeks post fracture
- creation of soft callus
- new blood vessels invade haematoma, decrease pain and swelling
- fibroblasts derived from periosteum invade and colonise haematoma
- fibroblasts produce collagen fibres (granulation tissue)
- collagen fibres loosely linked to the bone fragments
- cells of granulation tissue gradually differentiate to form fibrous tissue and fibrocartilage
Hard callus formation
3-12 weeks post fracture
- endochondral ossification converts soft callus to woven bone starting at periphery and moving towards centre, further stiffening healing tissue
- continues until no more inter fragmentary movements
Remodelling process
Takes months-years
- conversion of woven bone into lamellar bone through surface erosion and osteomalacia remodelling once inter fragmentary movement ceases
- fracture healing becomes complete with remodelling of medullary canal and removal of parts of external callus
Primary bone healing
Intramembranous healing
Haversion canals form across the bone to aid healing
No fracture callus forms
Only occurs if edges are in close proximity
Absolute stability
Fracture callus
Temporary formation of fibroblasts and chondroblasts at the site of bone fracture where the bone heals
What affects bone healing
Diet
Diabetes
Nicotine
Medications- biphosphates, steroids NSAIDs
Secondary bone healing
Endochondral healing
Periosteal healing occurs via formation of a callus
Callus undergoes mineralisation and remodels to form bone tissue
Relative stability
Post menopausal osteoporosis treatment
Same therapy for prevention and treatment
Oral biphosphonate is first line
IV biphosphonate alternative if oral biphosphonate
HRT additional option if younger post menopausal woman, (adverse effects of CVD and cancer if used in older women and for long term use)
Teriparatide
Osteoporosis in postmenopausal women
Most frequent
Natural loss with ageing exacerbated
Lack of oestrogen promotes bone resorption (high turnover)
Most bone loss in first 10 years after menopause or oophorectomy
Oral biphosphonate
First line - alendrotnic acid, ridedronate sodium
Antifracture efficacy
Decreased occurrence of vertebral, non vertebral and hip fractures
Absorbed into hydroxyapatite
Induced apoptosis of osteoclasts
Decreased rate of bone turnover
IV biphosphonate
Ibandronic acid, zoledronic acid, denosumagb, raloxifene
Alternative if intolerant of oral biphosphonate or contraindicated
Teriparatide
Treatment limited to 24 months
Reserved for post menopausal women - severe osteoporosis
High risk of vertebral fracture
Useful investigations in the diagnosis of bone disease
X-ray BMD (DEXA calcaneum screening) DEXA (dual energy xray absorptiometry) FRAX Hormone levels Quantitative CT scan Body composition analysis to detect bone loss MRI
BMD screening
> -1 - normal
< -1 or >-2.5 osteopenia
Foot print changes from 6 months to adulthood
Starts much flatter and ends with a high medial arch
Medial longitudinal foot arch
Begins at the calcaneus, rises to the talus, then descends through the navicular, cuneiforms, and the head of the first three metatarsals
Lateral longitudinal arch
Composed of the calcaneus, talus, cuboid, and the fourth and fifth metatarsals
L and flatter than the medial longitudinal arch.
Transverse arch
Arch over the top of the foot
Cuboid, cuneiforms, base of 5 metatarsals and heads of metatarsals
Locomotion- walking cycle
- heel contact
- flat foot (toe down)
- mid stance
- heel off
- push off
- toe off
60% stance, 40% swing
Waling involves pelvic tilt and vertebral sway
Double support
When both feet are in contact with the ground at the same time
Gait changes with age
Strength peaks in 20s and declines after 5th decade
Gait speed slows
Age related changes in balance - compensatory responses
Age related decrease in balance and strength contribute to higher incidence of falls in older people
Posture doesn’t really change just with ageing, usually caused by disease
Older people walk with a 5 degree greater ‘toe out’ - possible reduction in internal rotation of hip
Gait velocity falls due to shorter steps
Rhythm doesn’t really change with age
Double stance increases with age
Double stance increasing with age
20% -> 26%
Decreased momentum
Reduced time for swing leg to advance - shorter step length
Elderly people with a fear of falling have an increased double stance time
Diplegic gait
Seen in people with cerebral palsy
Spasticity in limbs, usually lower
Abnormally narrow base
Drag both legs, scraping toes
Hemiplegic gait
Most commonly seen in stroke
Unilateral weakness on affected side causing leg drag
Arm flexed, adducted and internal rotated
Leg in extension with plantar flexion of the foot and toes
Trendelenburg gait
Drop in pelvis on non weight bearing leg
Indicates hip abductor (gluteus medius and minimus) weakness on weight bearing leg
Seen in muscular dystrophy
Ataxic/cerebellar gait
Wide base
When standing still, may sway back and forth
Clumsy, staggering movements
Not able to walk heel-toe or in a straight line
Neuropathic gait
Foot drop
Many causes including perineal nerve palsy, Charvot-Marie-Tooth disease
Parkinsonian gait
Rigidity Bradykinesia Stooped head, neck forward Flexion at knees Slow, little steps - shuffling gait Difficulty initiating steps and turning Festination Loss of arm swing
FRAX score
Tool to predict the chances of developing another fracture
If FRAX is high, need to find ways of decreasing the incidence of fracture
What is included in a FRAX assessment
Age of patient Sex (females more prone to osteoporosis) Weight (too light or too heavy) Height Previous fracture Smoker Glucocorticoids Rheumatoid arthritis Osteoporosis Alcohol
What does the FRAX score tell you
10 year risk of major osteoporotic fracture and also 10 year risk percentage of hip fracture
- if high risk, modify lifestyle: stop smoking/alcohol, osteoporosis scan, treatment for osteoporosis
How to use FRAX clinically
Treat like the patient has osteoporosis if the chance hip fracture is greater than 3% in the next 10 years and the chance of other major osteopathic fracture is greater than 20% in the next 10 years
Clinical implications associated with ageing
Polypharmacy
Multimorbidity
Non specific presentations - more complex appointments
Problems with communication
Health issues associated with ageing
Sexual dysfunction - ED in men Increased risk of cancer Osteoporosis Falls Gait problems Malnutrition Dementia and parkinsons
