Case 8 Hip Fracture Flashcards
What are risk factors of osteoporosis?
- Low oestrogen Female after menopause
- Low serum calcium
- Alcohol consumption
- Smoking
- Malnutrition/malabsorption celiac, IBD
- Medication glucocorticoid, heparin, L-thyroxine
Antagonists of Vit D dec Ca2+ absorption from GUT - Physical inactivity
Lack of stress on bones dec bone deposition, in resorption - Vit D deficiency low exposure to sunlight (concealing clothing), dark skinned people
- Diseases
Turner Syndrome, hyperprolactinemia (induce low oestrogen level), Klinefelter Syndrome, Cushing Syndrome, DM, hyperthyroidism (inc basal metabolic rate), hyperparathyroidism
What are primary and secondary osteoporosis?
primary - postmenopausal, senile, calcium deficiency secondary - drug-induced - endocrine diseases
What are symptoms of osteoporosis?
usually asymptomatic until fractures occur
- vertebral/compression
- hips, wrists, femoral neck, distal radius
Diagnosis of osteoporosis
fragility fractures OR DEXA scan - T score (deviation away from young normal population) < -2.5 --> osteoporosis -2.5
What is the treatment for osteoporosis?
Risk factor reduction
- smoking, alcohol cessation
- inc calcium intake
- enough sun exposure and Vit D supplement
- weight-bearing exercise
- prevent falls
Medication
- Vit D and calcium supplement
- bisphosphate (inhibit osteoclasts to prevent bone breakdown)
- RANKL inhibitor (inhibit osteoclasts maturation)
- SERM –> postmenopausal, binds and induces conformational changes of oestrogen receptors
What are different types of femur fractures
Femoral neck (intracapsular) - subcapital: just below the head - midcervical: across neck - basicervical: base of neck young people from MVC elderly fall from standing
Intertrochanteric (extracapsular) including greater and less trochanters and transitional zone b/w neck and shaft
Subtrochanteric including below less trochanters and proximal femoral shaft
Risk factors for falls
- Oestopprosis/osteopenia 3 fold inc
- Age > 65
- Low BMI
- Elderly: fall from standing height SCREEN FOR SECONDARY CAUSES
- Recurrent falls
- Female
- High energy trauma in young
What are some differentials for fall
accidents: trips/falls, fall hazards (footwear, slippery bathmat, hearing/vision impairment, incontinence at night)
Diseases: CVS, neuro, MSK
medications: polypharmacy, antidepressants/antipsychotics, sedatives, diurectics, antihypertensives
Physical exams for hip fractures
- Shortening and external rotation of the fractured hip
Shortening: NOF fracture is above the attachment of iliopsoas muscles, which is the lesser trochanter. When fracture occurs, the iliopsoas muscles have the ability to pull the lesser trochanter higher than when its intact.
External rotation: iliopsoas muscles originate medially from the vertebrae and attach to the lesser trochanter. Due to the displacement of the femur from the fracture, the axis of action of iliopsoas muscle is altered. Hence, along with external rotator muscles such as gluteus maximus, the displaced femur is being elevated and eternally rotated.
Investigations for hip fractures
ray (order in all patient with hx of fall/presenting with hip pain)
- AP/lateral of pelvis and affected hip
- Displacement: shortened femoral neck, disruption of Shenton line, bone overlap, less trochanter more prominent due to external rotation of the hip
secondary causes
- ECG
- CBE, blood group and hold, coagulation studies, EUC
What are some pre-operative management?
- IV fluids, oxygen, catheter –> vitals, haemodynamically stable
- Capacity of consent by doing a baseline cognitive screening (SDM, next of kin)
- ask for end of life care/ADC discuss patient’s wishes of following treatment
- Resuscitation plan (7 step pathway resus plan) should be done at admission
Analgesia - Should be offered on presentation
- Unless contraindicated, paracetamol is given and 6 hourly after
- Opioids as required
Check for INR due to warfarin
- Stop warfarin, give Vit K/prothrombinex/FFP
- If INR<1.5, surgery can proceed
Relevant investigations
- ECG
- CBE, blood group and hold, Coagulation studies, EUC
What are some post-operative management?
- Monitor urine output and give fluid accordingly
Oliguria: first sign that smth is wrong - Anticoagulant (VTE prophylaxis) mobilise within 24 hours, stocking compression
Analgesia
Antibiotics (2 hrs pre-operation, 24 hrs post operation), wound infection and MRSA
Aperients (laxatives)
All other patient medications: chart and RECOMMENCE - Compartment syndrome secondary to surgery
- Falls prevention education
- Would site inspection
- DEXA scan
- ACAT assessment need for home care package, aged care home, transition care ask functional status, medical health and lifestyle, memory problems, issues relating to home and personal safety, speaking to GP
What are some causes of post-operative dyspnoea?
- Pneumonia
- PE due to DVT
- Infection leading to sepsis
- Resp failure due to opiate overdose/anaesthetic agents causing neuromuscular block not reversed
- HF/fluid overload
- Exacerbation of COPD, MI/ACS
What some allied health for hip fracture?
- OT: inc independence in daily activities, falls assessment and prevention
- Pharmacy: patient education with ongoing medications upon discharge, complete pharmaceutical review
- Physio: primary rehab (weight bearing), gait and balance, inc mobility, falls prevention
- Social worker: complete psychosocial assessment, assist in transition to other care facilities
- Dietician: nutritional balance + osteoporosis support
What are some fall prevention?
- Identification and treatment of osteoporosis
nutrition, alcohol/smoking cessation, medications - Fall assessment of household
remove hazards, assistance at home such as handrails - Adequate weight-bearing exercises
- Talk to pharmacists regarding side effects of medications and any changes should be made
- treat secondary causes
- talk to podiatrists to check for proper shoe wear
What is MRSA
- Age > 50
- Indwelling device/current wound
- Previous hx of MRSA
- Prior antibiotics use
- HIV infection
Management
- Vancomycin IV if severe
- Clindamycin, doxycycline orally
Warfarin vs DOAC
Warfarin - Mechanical valves, non-valvular Afib, pregnancy, blood clots due to malignancy HAVE TO BE on warfarin Can be monitored via INR Reversal agents (Vit K, Prothrombinex, FFP) Inferior in action More drug and food interaction Required warfarin Education Inc risk of intra-cranial haemorrhage Titration possible Extensive studies have been done Once a day
DOAC Cannot be monitored so compliance is KEY Only available for dabigastran but expensive Superior in action Minimal interaction Easy to use less risk of intra-cranial haemorrhage Less info on dosing only two doses (prophylactic and treatment doses) no titrating possible Less data for extreme age, underweight Twice a day (might affect compliance)
MOA of warfarin
- Inhibit Vit K by inhibiting VKOR inhibit Vit K dependent activations of factors II, VII, IX and X (2,7, 9, 10) as well as protein C and S which are anticoagulants
initial precoagulant when first started and full effect takes 3-5 days
suitability
- bleeding risk: current bleeding ulcers, severe thrombocytopenia, current alcoholism –> might use heparin
- INR: if cant have INR, NO WARFARIN
refuse to have INR (needle phobia, frequent visits)
- Need to be able to make warfarin dosage changes based on INR
Deaf patients: go in face to face and have new dosage written down
Cognitively intact to understand new dosage and how to change
New medication can affect INR level
What’s the target INR for monitoring
2-3
INR daily until INR stable alternate daily, twice a week, weekly and eventually monthly
Interrupting warfarin for surgery
o For minor procedures where bleeding risk is low –> continue
o Surgeries can be conducted with minimal risk of bleeding if INR < 1.5
o Warfarin can be withheld for 5 days before surgery, or IV Vit K given night before surgery
o Prothrombinex use should be restricted to emergency settings
What are some reversal agents for warfarin?
Vit K: oral route takes 24hr, IV route within 6-8 hours
Prothrombinex –> INR > 1.5 and urgent surgeries
- containing factor II, IX and X
- small amount, fast onset of 30 min
- Vit K might be needed to sustain the reversal effect
FFP
- When prothrombinex is unavailable, along with Vit K to sustain the reversal effect
- Life-threatening bleeding or INR > 10 accompanied by high risk of bleeding FFP is used in addition to prothrombinex
- Have to be cross-matched chance of adverse reaction, have to give slowly
What happens with warfarin after surgery?
Recommence warfarin the night of surgery
For patient with high bleeding risk, start low molecular weight heparin/unfractionated heparin for 12-24 hours continue LMWH or UFH for minimum 5 days and cease 48 h after target INR is reached
MOA of DOAC
Apixaban and rivaroxaban: Factor Xa inhibitor block thrombin production, conversion of fibrinogen to fibrin and thrombus formation
- Reversible inhibitors: short half-life around 12 hours
- They have different clearance pathways do not act on Vit K so FEWER drug interactions and NO food interactions
If patient cannot have oral anticoag, what other choices to prevent VTE?
- Subcut heparin
- IVC filter
What is Polypharmacy?
- Concurrent use of 5+ regular medications
- Drug-drug interactions, less likely to adhere, more adverse drug reactions, inc risk of falls/hospitalisation/medication errors, inc costs
How is consent obtained?
DECISION SPECIFIC
assess the capability of
- understanding the information that may be relevant to the decision, including the consequences
- retaining such info even for a short time
- using info to make decisions
- communicate the decision
- not under influence of alcohol, drugs, psychiatric conditions
Who can consent for a person with impaired decision-making capacity?
If there’s ACD –> SDM
If no ACD
- guardian with healthcare decision making power appointed by Guardianship Board
- prescribed relative with a close and continuing relationship
- close friends available
- someone in charged with day to day care such as nursing staff in aged care
- guardianship board/tribunal (last resort)
Discharge against medical advice
- over age 16 with decision-making capacity (consent can be removed as long as they have capacity)
- risk of morbidity and mortality does not stop the patient from leaving
What is treatment for Garden classification?
Garden I: no displacement, internal fixation to prevent displacement
Garden II: no displacement, internal fixation to prevent displacement
Garden III: some displacement, young: ORIF, elderly: hemi/total-hip arthroplasty
Garden IV: complete displacement, young: ORIF, elderly: hemi/total-hip arthroplasty
What are some complications of hip fractures?
thromboembolic complications avascular necrosis non-union Early local: compartment syndrome, infection early systemic: sepsis, DVT/PE Late: malunion, osteomyelitis
What is the blood supply of the hip?
The profunda femoris artery or sometimes femoral artery gives
- medial and lateral circumflex arteries –> extracapsular arterial ring
- retinacular arteries arise from medial circumflex artery give rise to subsynovial arterial ring that supplies the base of femur head
- epiphyseal arteries perforate into femur neck
- foveal artery (from obturator artery) inside ligamentum teres
What is the structure of bones?
Compact bones outside and spongy/trabecular bone inside
Osteon (compact bone)
- haversian canal in the centre (blood supply and nerve)
- lamellae (calcium phosphate) around haversian canal
- between lamellae –> lacunae containing osteocytes
How does bone remodelling occur?
Osteoclasts: bone resorption/breakdown
Osteoblasts: bone formation
- Osteoblasts sense micro cracks, produce RANKL (Receptor Activator of Nuclear Factor Ligand)
- RANKL binds to RANK receptors on nearby monocytes –> fuse together to form & activate a multinucleated osteoclast
- Osteoclast secretes lysosomal enzymes (collagenase) –> digest collagen protein in organic matrix
HCl –> dissolve hydroxyapatite –> calcium + phosphate into bloodstream - Osteoclasts also phagocyte osteocytes that are trapped within bony matrix
- Osteoblasts secrete OPG –> binds to RANKL to prevent it activating RANK receptors –> slow down the activation of osteoclasts
- When osteoclasts complete their job –> apoptosis
- Osteoblasts secrete osteoid seam to fill in lacunae –> calcium + phosphate –> Hydroxyapatite
- Osteoblasts get trapped within tiny lacunae become osteocytes
How does bone remodelling affect by hormones?
- Low Serum Ca2+ –> Parathyroid glands release PTH –> stimulate osteoblasts to release RANKL –> bone resorption –> release calcium into blood
- High Serum Ca2+ –> Parathyroid glands –> parafollicular cells release calcitonin –> inhibit PTH –> osteoblasts secrete OPG –> inc. bone formation & dec. bone resorption –> dec blood calcium
- Vitamin D –> promote Ca2+ absorption in gut –> inc. Serum Ca2+ –> parathyroid glands –> Calcitonin release –> inhibit PTH –> inc. bone formation & dec. bone resorption
What are the steps of fracture healing?
- Fracture haematoma
Fracture breaks blood vessels, leading to bleeding and clot formation. It eventually forms a haematoma –> death of bone cells around fracture. - Cartilaginous/soft callus
Chondrocytes from endosteum have created an internal callus via secretion of fibrocartilaginous matrix between the two ends of broken bone.
Chondrocytes and osteoblasts create an external callus of hyaline cartilage to stablish the fracture - Bony/hard callus
Osteoclasts resorb dead bones.
Osteogenic cells become active, differentiating into osteoblasts.
Cartilage in callus is replaced by trabecular bone –> bony callus of spongy bone - Remodelling
Internal and external callus unite –> compact bone replaces spongy bone
