CASE 8 - FNOF

Question 1

Neck of femur fractures typically occur in the…

But can also occur in young patients as a result of…

Answer 1

Neck of femur fractures typically occur in the ELDERLY

But can also occur in young patients as a result of high-energy trauma (e.g. car crash)

Question 2

Name 3 factors which contribute to the stability of the hip joint

Answer 2

1. 12 muscles surrounding the coxafemoral joint
2. CAPSULE: composed of 3 ligaments (iliofemoral, ischiofemoral, pubofemoral)
3. Depth of the coxafemoral joint (compared to the glenohumoral joint, another ball and socket joint which has much less stability due to its shallowness)

Question 3

State the following information for INTRACAPSULAR NOF fractures:

• Location
• Prognosis
• Risk of avascular necrosis
• Damage to joint capsule

Answer 3

INTRACAPSULAR

Location: proximal to the intertrochanteric line

Prognosis: worse

Risk of avascular necrosis: high

Damage to joint capsule: YES (consequently, blood supply from the femoral circumflex arteries and nutrient arteries inside the bone are disrupted. The ligamentum teres remains, but this is insufficient).

Question 4

State the following information for EXTRACAPSULAR NOF fractures:

• Location
• Prognosis
• Risk of avascular necrosis
• Damage to joint capsule

Answer 4

EXTRACAPSULAR:

Location: below the intertrochanteric line

Prognosis: better

Risk of avascular necrosis: low (but there is a risk of massive bleeding lol)

Damage to joint capsule: NO (therefore better fracture healing)

(LOOK @ GEEKYMEDICS)

Question 5

Describe the 4 stages of the Garden classification for FNOF.

Answer 5

Stage 1: incomplete fracture line or impacted fracture

Stage 2: complete fracture line, not displaced

Stage 3: complete fracture line, partially displaced

Stage 4: complete fracture line, completely displaced

STAGES 1 & 2: NON-DISPLACED
STAGES 3 & 4: DISPLACED

Question 6

What does Pauwel’s classification of femoral neck fracture involve?

What are the 3 stages?

Answer 6

Defines FNOF based on the orientation and direction of the fracture line across the femoral neck.

3 STAGES:

1. STABLE, obliquity between 0-30 degrees
2. LESS STABLE, obliquity between 30-50 degrees
3. UNSTABLE, obliquity between 50-70 degrees (or more)

Question 7

As the fracture becomes more vertical, the instability…

Answer 7

As the fracture becomes more vertical, the instability INCREASES

Question 8

List 4 risk factors for a FNOF

Answer 8

Age (≥65 years in women and ≥75 years in men)

History and risk factors of osteoporosis including menopause, amenorrhoea, smoking, excessive alcohol or caffeine intake, physical inactivity, long term or high dose corticosteroid use

Previous fragility fracture

History of falls

Poor nutrition (e.g. low calcium)

Low body mass index (<18.5kg/m2)

Dementia

Visual impairment: due to the increased risk of falls

History of tumours (primary or secondary bone tumours, breast, bowel, prostate, kidney, lung, thyroid tumours)

Question 9

Name 3 symptoms of a FNOF

Answer 9

1. Pain: in the groin, hip, or knee
2. Inability to weight-bear
3. Decreased or painful mobility of the affected hip

Question 10

List 5 clinical findings of a FNOF

Answer 10

1. Leg is abducted, shortened, and externally rotated
2. Palpation of the hip causes pain
3. Cannot perform straight-leg raise (useful for discerning occult hip fractures)
4. Soft tissue symptoms: bruising, swelling
5. Log roll test: pain on gentle internal and external rotation of the affected leg

Question 11

Name the bedside investigation, laboratory investigations, and imaging that should be ordered for a FNOF.

Answer 11

BEDSIDE INVESTIGATION: ECG

LABORATORY INVESTIGATIONS: basic bloods (CBE, EUC, coags), creatinine kinase, urinalysis, group and save

IMAGING: X-ray of AP pelvis and lateral hip (first-line), MRI (gold standard. Also useful if plain radiographs are unrevealing)

Question 12

Explain why you would want to order an ECG for a FNOF

Answer 12

To determine the underlying cause: may identify an arrhythmia or cardiac event that precipitated the fall

Question 13

Explain why you would want to order:

• Baseline bloods (CBE, EUC, coags)
• Creatinine kinase
• Urinalysis
• Group & save

for a FNOF

Answer 13

• Baseline bloods: good to know
• Creatinine kinase: potential rhabdomyolysis if they’ve been on the floor for a while
• Urinalysis: UTI or hyperglycaemia may have precipitated a fall
• Group & save: blood loss from FNOF can be severe, and the patient may need a transfusion

Question 14

Which analgesics are used for FNOF?

Answer 14

1. Paracetamol (decreases the number of opioids needed)
2. Opioids
3. Local nerve block (iliofascial/femoral nerve blocks)

Question 15

What are the principles of surgical management for FNOF?

Answer 15

URGENT reduction and internal fixation

EARLY mobilisation

Question 16

When should surgery for FNOF ideally be performed?

Answer 16

In stable patients without significant comorbidities, within 24 hours

AVOID DELAYING SURGERY FOR MORE THAN 72 HOURS FOR ANY PATIENT

Question 17

What are the benefits of early mobilisation after surgery?

Answer 17

Prevention of post-operative complications, e.g.

• Venous thromboembolism
• Pressure ulcers
• Muscle loss
• Bronchopneumonia

Question 18

Falls in geriatric patients are often multi-factorial. List 5 INTRINSIC and 5 EXTRINSIC causes of falls.

Answer 18

INTRINSIC:

• Postural hypotension
• Polypharmacy
• Specific drugs (e.g. beta-blockers, antihypertensives, benzodiazepines, diuretics)
• Stroke
• Seizure
• Dizziness
• Peripheral myopathy
• Poor vision

EXTRINSIC:

• Poor lighting
• Hazards (e.g. rugs)
• No assistive equipment
• Low toilet seats
• Hard-to-reach items

Question 19

Identify different grades of FNOFs based on X-RAY imaging

Answer 19

Shenton’s line disruption: loss of contour between normally continuous line from medial edge of femoral neck and inferior edge of the superior pubic ramus.

Lesser trochanter is more prominent due to external rotation of femur

Femur often positioned in flexion and external rotation (due to unopposed iliopsoas)

Asymmetry of lateral femoral neck/head sclerosis in fracture plane

Smudgy sclerosis from impaction

Bone trabeculae angulated

Question 20

Name the artery that is commonly implicated in avascular necrosis

Answer 20

Medial circumflex femoral artery (look up a photo)

Question 21

Why do FNOFs cause external rotation of the leg?

Answer 21

There is an imbalance between the external and internal rotators: the external rotators are stronger.

(all external rotators attach to the greater trochanter)

Question 22

Why is the risk of avascular necrosis higher for INTRACAPSULAR fractures?

Answer 22

There is damage to the joint capsule, disrupting majority of the blood supply to the femoral head

Question 23

What is a normal INR value?

Answer 23

0.9-1.2

Question 24

High INR values indicate…

Low INR values indicate…

Answer 24

High INR values indicate THIN BLOOD (increased risk of haemorrhage)

Low INR values indicate increased CLOTTING propensity (e.g. thromboembolism)

Question 25

The target INR range for patients receiving warfarin differs depending on the indication for warfarin therapy. For which patient groups is the target INR 2-3?

Answer 25

AFib Venous thromboembolism Mechanical heart valve (not mitral)

Question 26

The target INR range for patients receiving warfarin differs depending on the indication for warfarin therapy. For which patient group is the target INR 2.5-3.5?

Answer 26

Mechanical heart valve (combined mitral and aortic)

Question 27

How can the anticoagulant effects of warfarin be reversed? (4 methods)

Answer 27

- Reducing or witholding warfarin - Vitamin K1 - Prothrombinex-VF - Fresh frozen plasma https: //tgldcdp-tg-org-au.proxy.library.adelaide.edu.au/viewTopic?topicfile=anticoagulant-therapy&guidelineName=Cardiovascular#toc_d1e933

Question 28

How can osteoporosis be diagnosed? (2 methods)

Answer 28

1. Fragility fracture (pathological fracture resulting from a minimal-trauma fall) 2. DEXA scan (dual-energy x-ray absorptiometry): T-score < -2.5 SD (between the patient's BMD and the BMD of a healthy young adult)

Question 29

List 4 RFs for osteoporosis

Answer 29

``` Smoking Alcohol Malabsorption, malnutrition Low body weight FHx of osteoporosis ```

Question 30

What is the pathophysiology of primary osteoporosis? (Types I and II)

Answer 30

Type I: postmenopausal --> decreased oestrogen --> less stimulation of osteoblasts and less inhibition of osteoclasts Type II: senile osteoporosis due to gradual loss of bone mass as patients age

Question 31

What is the pathophysiology of secondary osteoporosis?

Answer 31

Drug-induced / iatrogenic causes, most commonly from long-term CORTICOSTEROID use (but can also result from anticonvulsants, PPIs, etc.) Endocrine causes, e.g. hyperthyroidism, hypogonadism

Question 32

What is the MOA of bisphosphonates? What are common side effects?

Answer 32

Inhibition of osteoclasts, decreasing bone resorption Hypocalcemia GORD --> oesophagitis NV Osteonecrosis of the jaw

Question 33

What is the MOA of denusomab? What are common side effects?

Answer 33

A MAB against RANKL. Targets RANKL, which normally binds to RANK to stimulate OSTEOCLAST activity. Binding to RANKL = less osteoclast stimulation Common side effects: hypercholesterolaemia, eczema, MSK pain (in men)

Question 34

Apixaban and Rivaroxiban are Factor ___ inhibitors

Answer 34

Apixaban and Rivaroxiban are Factor Xa inhibitors

Question 35

Discuss 3 suitability issues related to DOACs

Answer 35

- No reversibility agents (there is for dabigatran, but it's expensive and not commonly used) - No monitoring option, making compliance essential - No monitoring & dosing info for the following demographics: extremes of age, frail, underweight - Renal impairment

Question 36

Discuss 3 suitability issues related to Warfarin

Answer 36

1. Bleeding risk 2. Requires regular INR monitoring: becomes an issue if people are needle-phobic, 3. Need to be able to adjust warfarin dose based on INR results (e.g. mental capacity) 4. Hepatic impairment (though some are mixed)

Question 37

What is the MOA of warfarin? What are common side effects?

Answer 37

Vitamin K antagonist; inhibits synthesis of vitamin K-dependent clotting factors (II, VII, IX, X) and the antithrombotic factors protein C and S. Common side effects: bleeding

Question 38

What are the possible outcomes one year after a FNOF?

Answer 38

1/3 recover completely 1/3 have permanent disability 1/3 die

Question 39

Outline the surgical management of displaced and nondisplaced hip fractures

Answer 39

DISPLACED: poorer prognosis. Hemiarthroplasty where the head of the femur is replaced with a prosthesis. NON-DISPLACED & INTERTROCHANTERIC: internal fixation with screws

Question 40

Name 3 types of hip fracture and the implications of each one

Answer 40

1. Femoral neck/subcapital fracture: high risk of AVN and nonunion. High mortality in the elderly. 2. Intertrochanteric fracture: less AVN risk because it's EXTRACAPSULAR, but there is risk of ecchymosis 3. Subtrochanteric fracture: typically due to high-stress load. Risk of nonunion and ecchymosis. https: //www.youtube.com/watch?v=y5my4uXomls

Question 41

Name the hip fractures that fall under the INTRACAPSULAR and EXTRACAPSULAR categories

Answer 41

INTRACAPSULAR: femoral head and neck EXTRACAPSULAR: intertrochanteric, trochanteric, subtrochanteric

Question 42

What are the benefits of prothrombinex in patients with CHF?

Answer 42

Dry powder mix: won't affect fluid status

Question 43

What is an ACAT assessment?

Answer 43

The Aged Care Assessment Team (ACAT) assesses the needs of older people. It makes recommendations for government-funded care and support. Must be >65 years old (or >50 for Aboriginal and Torres Strait Islanders)

Question 44

Which neurovascular obs should be checked for compartment syndrome?

Answer 44

5 P's: ``` Pain Pallor Pulselessness Paresthesia Paralysis ```

Question 45

Why is the leg shortened and externally rotated in FNOFs?

Answer 45

Shortening and external rotation of the leg occurs because the muscles acting on the hip joint rely on the CONTINUITY of the femur. When there is displacement of the femur, the actions of the iliotibial tract and gluteus maximus are unopposed. The iliotibial tract pulls the leg UP (causing shortening) and the gluteus maximus causes external rotation.

Question 46

Name the 3 types of INTRACAPSULAR fractures

Answer 46

- Subcapital - Transcervical - Basicervical https://www.radiologymasterclass.co.uk/tutorials/musculoskeletal/x-ray_trauma_lower_limb/hip_fracture_x-ray

Question 47

Name the 2 types of EXTRACAPSULAR fractures

Answer 47

- Intertrochanteric - Subtrochanteric https: //www.radiologymasterclass.co.uk/tutorials/musculoskeletal/x-ray_trauma_lower_limb/hip_fracture_x-ray

Question 48

List 3 adverse effects of bisphosphonates and denosumab

Answer 48

BISPHOSPHONATES: - GORD - NV - Diarrhoea - Hypocalcemia - MSK pain - Osteonecrosis of the jaw DENOSUMAB: - Eczema - Hypercholesterolaemia - Musculoskeletal pain (in men)

Question 49

DEXA scan costs & benefits?

Answer 49

.

Question 50

Name 2 triggers for instituting a resuscitation plan

Answer 50

- Surprise question - SPICT tool etc. https://www.sahealth.sa.gov.au/wps/wcm/connect/11f77a004dc97fde967dfeb05b75bb55/Tool+1-+Resuscitation+Plan+7+step+diagram+WebS.pdf?MOD=AJPERES&CACHEID=ROOTWORKSPACE-11f77a004dc97fde967dfeb05b75bb55-nwLZqqr

Question 51

Why is Enoxaparin initiated alongside warfarin for post-operative DVT prophylaxis?

Answer 51

There is a delayed effect when using warfarin (can take a few days for it to work). The anticoagulation effect of enoxaparin is more immediate; it stimulates antithrombin III, which inhibits factor X and thrombin. As a result, fibrin is not produced (clots required fibrin and platelets). Fibrin has a half-life of around 60 hours; warfarin does not affect fibrin, so the existing fibrin in the bloodstream can still contribute to clotting risk. Proteins C and S (which warfarin act on, and which inhibit coagulation) also have shorter half-lives than most of the vitamin k-dependent clotting factors that are inhibited by warfarin, resulting in a pro-coagulable state for the first few days.

Question 52

To which drug class does Enoxaparin belong?

Answer 52

LMWHs / low-molecular weight heparins

Question 53

What is the mechanism of action of LMWHs?

Answer 53

Binds to antithrombin III, subsequently inactivating clotting factors IIa and Xa. Fibrin cannot be formed. https://www.youtube.com/watch?v=gM5q-7JHnqw

Question 54

Name the contents of the femoral triangle, from lateral to medial

Answer 54

NAVEL: - Femoral nerve - Femoral artery - Femoral vein - Empty space (to accommodate different levels of flow/distension of the vessels) - Lymph nodes (within the femoral canal)

Question 55

Benzodiazepines act by potentiating the effect of which neurotransmitter?

Answer 55

GABA Benzodiazepines potentiate the inhibitory effects of GABA throughout the CNS, resulting in anxiolytic, sedative, hypnotic, muscle relaxant and antiepileptic effects.