Hip and Proximal Femur Fractures

Question 1

Occurrence of proximal femur fractures?

Answer 1

Most are in those >80 years and 75% are female

Very common due to increase in the ageing population and osteoporosis

Question 2

Causes of proximal femur fractures?

Answer 2

Falls:
• There may be an underlying cause - CV disease (e.g: TIA), cardiac arrhythmia, postural hypotension
• Mechanical fall
• Usually, no obvious organic cause falls

Osteoporosis:
• Age-related qualitative defect of bone (more common in females)
• May be related to smoking, alcohol, steroids

Question 3

Why do most people have surgery, despite the assoc. morbidity and mortality?

Answer 3

Non-operative Mx is very painful and the risk of prolonged bed rest are just as high as the risk of surgery

Surgery affords the best chance of returning home

Question 4

Which patients do not have surgery for proximal femur fractures?

Answer 4

Patients with severe co-morbidites (massive stroke, MI, etc) and those who are expected to die with surgery

Question 5

Consequences of proximal femur fractures, in terms of independence?

Answer 5

Most patients drop a level of mobility:
• Stick - 2 sticks - walker / frame - needs assistance - wheelchair - hoist

Independent patients have a 1/5 risk of requiring institutional care

Question 6

What are the risk of surgical complications?

Answer 6

• Failure of fixation (screws may not hold in osteoporotic bone)
• AVN (avascular necrosis)
• Non-union
• Infection (risk is higher with this surgery than for THR)
• Dislocation

Question 7

Examination findings with a proximal femur fracture?

Answer 7

• Shortened and externally rotated leg
• Trochanteric bruising and tenderness
• Unable to SLR
• Severe groin pain on rotational movements

Question 8

What is the most powerful flexor of the hip joint?

Answer 8

Iliopsoas

Question 9

Describe the blood supply to the femoral head

Answer 9

Branches of the femoral artery winds around the neck and branches of these supply the femoral head

Artery of ligamentum teres only supplies 5%

Question 10

What is the capsule of the hip joint?

Answer 10

AKA capsular ligament - strong and dense

Question 11

3 types of proximal femur fractures?

Answer 11

• Intracapsular - inv. the femoral neck, between the edge of the femoral head and insertion of the capsule of the hip joint
• Extracapsular - distal to the insertion of the capsule, inv. or between the trochanters
• Subtrochanteric - below, but no more than 5 cm below, the lesser trochanter, i.e: inv. the proximal femoral shaft at/just distal to the trochanters

Question 12

Ix for proximal femur fractures?

Answer 12

X-ray (GOLD STANDARD - require 2 views at 90 degrees to one another)

MRI for occult fractures

Question 13

Complications of intracapsular proximal femur fractures?

Answer 13

Can interrupt the blood supply and there is a risk of AVN (higher with displaced fractures); AVN is not a risk with extracapsular fractures

Risk of non-union

Question 14

Signs of fractured proximal femur on X-ray?

Answer 14

Interrupted Shenton’s line - imaginary line drawn along the inferior border of the superior pubic ramus and along the inferomedial border of the neck of femur; it should be continuous and smooth (DIAGNOSTIC if interrupted)

Centre of the femoral neck does not bisect the centre of the femoral head

Question 15

Treatment of intracapsular proximal femur fractures?

Answer 15

Replacement is a reliable option:
• Hemiarthroplasty (acetabulum is left alone) is used in those with poorer function/cognitive deficit as there is a lower chance of dislocation
• THR gives a better functional outcome but there is a higher dislocation rate

Consider fixation in:
• Undisplaced fractures
• Intracapsular fractures in a younger patient

Question 16

What to do if the MRI is +ve for an intracapsular proximal femur fracture but the X-ray is -ve?

Answer 16

There is a risk of displacement with weight-bearing

Surgery may provide better pain relief and easier rehabilitation but the pros and cons should be discussed with the patient and their family

Question 17

Complications of internal fixation for intracapsular proximal femur fractures?

Answer 17

Fixation may fail, e.g: screws slide out, and this would then require a THR

Question 18

Treatment of extracapsular proximal femur fractures?

Answer 18

Usually heal with a sliding hip screw (Dynamic Hip Screw/DHS) which compresses the fracture site

An IM nail and sliding hip screw can also be used

Question 19

What does the success of fixation of an extracapsular fracture depend upon?

Answer 19

Quality of reduction

Centrality of screws in the head

Question 20

Occurrence of subtrochanteric fractures?

Answer 20

Assoc. with long-term bisphosphonate use

Question 21

Complications of subtrochanteric fractures?

Answer 21

Blood supply to this fracture site is not great so there is a higher risk of NON-UNION

Question 22

Treatment of subtrochanteric fractures?

Answer 22

Thomas splint or femoral nerve block can help with analgesia

IM nail is biomechanically superior (may last longer before breakage if there is delayed union)

Question 23

Describe pubic rami fractures

Answer 23

These are different from the high-energy pelvic fractures that tend to occur in young patients; these tend to occur in fragile patients who fall on their side

There is no major displacement or bleeding

Question 24

Examination findings with pubic rami fractures?

Answer 24

Tender groin

Less pain on rotation than in a hip fracture

Question 25

Treatment of pubic rami fractures?

Answer 25

Conservative Mx

Question 26

Treatment of greater trochanter fracture?

Answer 26

Usually conservative Mx

If an MRI shows that the fracture traverses the femoral neck, then internal fixation can be used

Question 27

Only proven method that prevents proximal fractures?

Answer 27

EXERCISE helps to maintain muscle strength and bone mineral density

There are no drugs that increase bone density; bisphosphonates may stop loss of bone density but they are assoc. with atypical fractures