Femur and hip

Question 1

Discuss AVN of the hip

Answer 1

Should be considered in any patient with increasingly painful hip buttock thigh or knee and no history of recent trauma.

It is the result of ischaemic bone death of the femoral head after compromise of its blood supply. It is bilateral 40-80% of cases

It is common in relatively young patients with a mean age at diagnosis of 38

Specific cause is not identified in 20% of cases but known atraumatic causes include 
-chornic corticosteroid
-chronic alcoholism 
Haemoglobinopathy 
dysbarism 
-chronic pancreatitis 

Traumatic AVN is a subacute manifestation after hip dislocation or femoral neck fracture it is a direct result fo disruption of the blood supply to the femoral head - time to hip reduction direct relationship to AVN with >12 hours causing AVN in 60% of cases compared to 5% when under 6 hours

Question 2

Discuss myositis ossificans

Answer 2

Pathologic bone formation at a site where born is not normally found. Traumatic myositis ossificant results most commonly from a direct blow to muscle.

Question 3

Discuss neoplastic disease of the hip

Answer 3

The most common neoplastic disease of bone is metastatic generally from breast, kindey, lung, thyroid or prostate

Primary bone lesesions can be osteoblastic or osteolytic, Osteosarcomas or osteochondroma

Question 4

Discuss contraindications to traction splints

Answer 4

• Pelvic fractures
• patella fracrture
• ligamentous knee injuries
• tib and fib fractures
• open fractures

Question 5

Describe classifcation of open wounds

Answer 5

Type 1 - usually from bony fragment piercing skin

• < 1cm
• minimal soft tissue damage
• cover with 1st gen cephalosproin

Type 2 - 1- 10cm

• moderate softer tissue damage without nerve or arterial damage
• variable mechanisms
• requires additional gram -ve cover - genta

Type 3 >10cm

• Extensive muscle devitalization; nerve and arterial involvement
• high energy shotgun, high velocity gun shots

Question 6

Discuss compartment syndrome of the thigh

Answer 6

Due to the large volume of the compartments in the thigh it is much rare as greater volume of bleeding is required.

Can be difficult to differentiate the expected amount of swelling from that of compartment syndrome in these injuries

Question 7

Discuss classification femoral neck fractures

Answer 7

Subcapital - femoral head /neck junction
transcervical - mid way through femoral neck
basicervical - through the base of the femoral neck

Question 8

Discuss management of femoral neck fractures

Answer 8

TO avoid further drisuption of the blood supply to the femoral head ROM should not be tested

Treatment consist of either ORIF, hemiarthroplasty or THA
In all displaced femoral neck fractures the femoral head is rendered largely avascular and signs of AVN and collapse might develop over the ensuring years

Question 9

What are the complications of femoral neck fractures

Answer 9

The two major complications of femoral neck fractrurs are AVN and non unioun

Joint infection, osteomyelitis, and PE are also frequent complications
Patient should be anticoagulated for at least 10 days post major hip surgery in patients without significant contraindications.

Question 10

Discuss intertrochanteric fractuers

Answer 10

Extends between the greater and lesser trochanters of the femur. These injuries are considered extracapsular.

The fracture line extends through cancellous bone which has execellent blood supply.

Often associated with other distant fractures caused by the same trauma such as distal radius, prximal humerus ribs and lumabr and thoracic spine

The majority of intertrochanteric fractures require fixation - should be performed on an urgent rather than emergent as stabilistaion and fluid status of the patient should be addreessed

Dynamic hip screw is treatment of choice
-intermedullary vs sliding hip screws

Question 11

Discuss isolated fractures of the greater or lesser trochanter

Answer 11

Rare fracture
Stable
Mainstay is pain control and early mobilisation

Question 12

Discuss sub trochanteric fractures

Answer 12

occur between the less trochanter and the proximal 5 cm of the femoral shaft - this region is almost entirely cortical bone which lacks the blood supply to form new bone

Occurs in two groups of patient

• extremely high energy trauma in which it is rarely an isolated injury
• elderly fall and fracture through already weakened area of cortex (malignancy, osteroporosis, osteogenic imperfecta, pagets disease)

Question 13

Discuss Femoral shaft fracture

Answer 13

Occurs in young adults with high energy trauma
Neurovascular injury is rare however bleeding into the thigh can cause significant haemorrhage

Fixed with intermedullary screws with good affect with almost 100% union

Question 14

Discuss hip dislocations

Answer 14

Hip joint has impressive inherent strength and stability and as such a dislocation should act as a red flag for significant systemic injury
As many as 70% of patient with hip dislocation have accompanying acetabulum fracture

Posterior dislocation are almost always the result of MVAs.

Posterior dislocation account for 80-90% of dislocations

Anterior account for 10-15%

• this can dislocate medial towards the obturator canal (obturator dislocation)
• or laterally towards the pubis (pubic dislocation)

Central dislocation (2-4%) are not true dislocation as the entire femoral head is forced centrally through a communicated fracture of the acetabulum

Inferior dislocation associated with ivnersion of the femoral shaft is very rare condition that occurs wiht or without assocatied trochanteric fracture.

Sciatic nerve is the most commonly affected in hip dislocations

Question 15

Discuss management of hip dislocations

Answer 15

True orthopeadic emergency and should be reduced as promptly as possible
Complications such as AVN, traumatic arthritis, permanent sciatic nerve palsy and joint instability increase logarithmically with the duration of dislocaiton

Question 16

Describe Allis technique for hip reduction

Answer 16

1) patient is in supine with hip stablised by assistanct
2) with the knee flexed apply steady traction in line with the deformity
3) slowly bring the hip to 90 degrees of flexion while applying steading upward traction and gentle rotation
4) ask the assistant to push the greater trochanter foward toward the acetabulum
5) once reduced bring the hip to the extended position while maintaining traction.

Question 17

Describe captain morgan technique for hip reduction

Answer 17

1) with the patient supine on the stretcher in its lowest position secure the pelvis to the stretcher with a bed , place the straps over the ischial wings and pubic symphysis
2) stand at the side of the bed and place one foot up on the bed
3) place the patients ipsilateral left over your leg so that your knee is resting in his or her pop fossa
4) while holding the ankle in position with slight downward pressure lift up with both legs to apply traction on the femur
5) if traction alone does not work us your hands to internally and externally rotate the leg to achieve the reduction

Question 18

List other reduction techniques for hip dislocations

Answer 18

Whistler
stinsons
Sciatic nerve palsy
Vascular injury

Question 19

List complications of hip dislocations

Answer 19

AVN - no risk for non native hips

Long term instability

Question 20

Describe the garden classification system

Answer 20

Used to classify intracapsular neck of femur fractures.
Type 1 – undispalced incomplete  
Type 2: undisplaced complete 
Type 3- Complete paritaly displaced  
Type 4- Compelte completely displaced  

Further classified into
Non displaced 1&2
Displaced 3&4