Neck of Femur Fractures

Question 1

List 4 factors which predispose an individual to neck of femur fractures

Answer 1

1. Increasing age
2. Osteoporosis
3. Female
4. Smoking

Question 2

How does a NOF present?

Answer 2

1. Shortened, abducted and externally rotated leg
2. Groin or hip pain, may radiate to the knee
3. Unable to weight bear

Question 3

Initial investigation of choice for a suspected NOF fracture?

Answer 3

AP and lateral X-rays

MRI or CT scanning may be used where the x-ray is negative, but a fracture is still suspected.

Question 4

What is a key sign on X-ray of a fractured NOF

Answer 4

Disruption of Shenton’s line

Question 5

What is Shenton’s line?

Answer 5

Continuous curving line formed by the medial border of the femoral neck and continues to the inferior border of the superior pubic ramus.

Question 6

On what x-ray view of the hip can Shentons line be seen?

Answer 6

AP

Question 7

Answer 7

Question 8

Give the 3 sources of blood supply to the femoral head

CHECK answer

Answer 8

1. Retinacular vessels
2. Intraosseous cervical vessels
3. The artery of the ligamentum teres

Question 9

Initial management of a NOF on admission

Answer 9

• Analgesia
• Investigations (X-rays)
• VTE risk assessment and prophylaxis (eg. LMWH)
• Pre-operative assessment (incl bloods and ECG)
• Orthogeriatrics input

Question 10

How are Intra-capsular NOF fractures classified?

Answer 10

Garden Classification ➞ undispaced (I/II) versus displaced (III/IV)

Increasing severity with increasing grade

Question 11

Which vessels are disrupted in a NOF fracture?

What is the implication of this?

CHECK

Answer 11

The intraosseous cervical vessels are disrupted

Femoral head nutrition is then dependent on remaining retinacular vessels and those functioning vessels in the ligamentum teres

Question 12

What defines an Intertrochanteric fracture?

How is this treated?

Answer 12

Occur between the greater and lesser trochanter

Treated with a dynamic hip screw (AKA sliding hip screw)

Question 13

What is a DHS?

Answer 13

Screw goes through the neck and into the head of the femur

A plate with a barrel that holds the screw is screwed to the outside of the femoral shaft

Allows compression of the fracture whilst maintaining the neck shaft angle of the femur

Question 14

Give 4 complications of a DHS

Answer 14

1. Cut out of lag screw through the femoral head
2. Detachment of plate from femur
3. Nonunion
4. AVN of femoral head

Question 15

The type of Inter-Trochanteric Fracture is based on what?

Answer 15

Number of parts - Increased severity with increasing grade

Question 16

What is defines a sub-trochanteric fracture?

How are these treated?

Answer 16

Fractures within 5cm distal to the lesser trochanter

May be treated with an IM nail

Question 17

What is an IM nail?

Answer 17

A metal pole inserted through the greater trochanter into the central cavity of the shaft of the femur

Question 18

What are the the deforming forces that act on the proximal fragment of a subtrochanteric fracture

Answer 18

1. Abduction; gluteus medius and gluteus minimus
2. Flexion; iliopsoas
3. External rotation; short external rotators

Question 19

What are the deforming forces that act on the distil fragment of a subtrochanteric fracture

Answer 19

Adduction and shortening; adductors

Question 20

Give 3 pros about operative-cephalomedullary nailing in the treatment of Subtrochanteric Fractures

Answer 20

1. preserves vascularity
2. load-sharing implant
3. stronger construct in unstable fracture patterns

Question 21

Give 4 cons about operative- cephalomedullary nailing in the treatment of Subtrochanteric Fractures

Answer 21

1. reduction technically difficult
2. nail can not be used to aid reduction
3. fracture must be reduced prior to and during passage of nail
4. may require percutaneous reduction aids or open clamp placement to achieve and maintain reduction

Question 22

What is an intra-capsular fracture?

Answer 22

A break in the femoral neck, within the capsule of the hip joint. Affects the area proximal to the intertrochanteric line

Question 23

What is the biggest danger with Intra-capsular fractures?

Answer 23

Blood supply to femoral head disrupted ➞ risk of avascular necrosis (AVN)

Question 24

Compare a displaced vs non-displaced intracapsular fracture

Answer 24

Displaced disrupts supply to the femoral head

Non-displaced may have an intact blood supply to femoral head

Question 25

List 3 Surgical managements for an Intra-capsular fractures

Answer 25

1. Internal Fixation
2. Hemiarthroplasty
3. THR

Question 26

When is Internal fixation used for Intra-capsular fractures?

Answer 26

Non-displaced or minimally displaced IC fractures

Also Displaced IC fractures in the young (but may require open reduction -orthopaedic emergency) or in the elderly (controversial)

Question 27

When is arthroplasty (hemi, THR) used for Intra-capsular fractures?

Answer 27

Displaced ICF

Question 28

Compare a Hemiarthroplasty vs THR?

When does one tend to be offered over another?

Answer 28

Hemiarthroplasty:

• Only head of the femur is replaced, the acetabulum is left in place.
• Generally offered to patients with limited mobility or significant co-morbidities

THR:

• Both the head of the femur and the socket are replaced.
• Generally offered to patients who can walk independently and are fit for surgery

Question 29

What is the most common approach for a hemiarthroplasty + explain?

List 2 risks of this

Answer 29

Lateral (Hardinge) Approach

• Fascia Lata split to expose Vastus Lateralis
• Splits both Gluteus Medius and Vastus Lateralis

Risks:

• Femoral nerve damage
• Denervation Gluteus Medius

Question 30

According to NICE guidelines, within what timeframe must a NOF fracture be surgically treated?

Answer 30

Either the same day or the day after the patient is admitted (within 48 hours).