Hip, Femoral and Knee Trauma

Question 1

What causes the majority of hip and femoral trauma?

Answer 1

Osteoporosis

Majority of patients are over 80, with 3/4s being female

Question 2

What is the mortality of a hip fracture at…

• 1 month
• 4 months
• 1 year?

Answer 2

1 month - 10%

4 months - 20%

1 year - 30%

Question 3

How much time is there typically between a hip fracturing and the patient being in surgery to manage it?

Answer 3

Almost all are done within 24 hours

Question 4

Describe the blood supply to the head of the femur

Answer 4

Ring anastomosis between the medial and lateral circumflex arteries

Both of these are branches off of the deep femoral artery (a.k.a. the profunda femoral artery)

There is also a branch of the obturator artery supplying the head of the femur directly known as the foveolar artery, or artery to the head of the femur

Question 5

What is the name of the ligament that attaches to the head of the femur?

Answer 5

The ligamentum teres

Question 6

What are the two classifcations of hip fracture?

Which is more likely to disrupt blood supply to the femoral head and result in AVN?

How does this affect management?

Answer 6

Intracapsular and Extracapsular

Intracapsular is more likely to disrupt the blood supply to the head of the femur and cause AVN. As a result, intracapsular hip fractures are more likely to require hip replacement

Extracapsula fractures can be fixed using internal fixation, and preserve the hip joint. Can use either compression or a sliding dynamic hip screw

Question 7

Where exactly do the fractures occur in a) intracapsular and b) extracapsular hip fractures?

Answer 7

Question 8

How is a Subtrochanteric femoral shaft fracture managed?

Answer 8

Pre-operative pain relief and stabilisation with a Thomas splint

Usually treated with strong fixation using an IM nail

Healing takes a long time due to poor blood supply and non-union occurs frequently

Question 9

Under what circumstances would you use a Thomas splint?

Answer 9

To immobilise fractures of the femur or around the knee

Question 10

How much blood loss can occur in a displaced femoral shaft fracture?

How are these fractures managed?

Answer 10

Up to 1.5L!

Fat can also enter the venous system, resulting in a fat embolism

Initial anaelgesia with a femoral nerve block and immobilisation with a Thomas splint

Then usually closed reduction and fixation with an IM nail

Question 11

Why do distal femoral shaft fractures usually cause the knee to develop a flexed position?

How are these usually treated?

Answer 11

Because of the pull of the gastrocnemii muscles

Distal femoral shaft fractures are typically managed with plates and screws (casting would be a difficult position to maintain)

Question 12

Why are “true” knee dislocations a surgical emergency?

Answer 12

High incidence of vascular injury, nerve injury and compartment syndrome

Will typically be very unstable as at least 3 of the 4 ligaments around the knee must have been ruptured for dislocation to occur. Mutliple ligament reconstruction will probably be required, and maybe also external fixation

Question 13

Almost all patellar dislocations are (medial/lateral)

What is the prognosis?

Answer 13

Lateral

Most spontaneously relocate after straightening the leg, but some may require manipulation. Haemarthrosis may occur

Around 10-20% of people with patellar dislocations will go on to have another, and 50% of these will have multiple further dislocations

Question 14

What classification system is used to score fractures of the proximal tibia (plateau fractures)?

How are they managed?

Answer 14

The Schatzker system is used to assess these fractures (similar to Salter-Harris)

Treated with fixation using plates and screws

Temporary external fixators spanning the joint may also be used before definitive ORIF