Injuries to bones and joints of the lower limbs

Question 1

What is a fracture?

Answer 1

Breach of the integrity of part or whole of the bone

Question 2

What is a subluxation?

Answer 2

Partial separation of the articular surface of a joint

Question 3

What is a dislocation?

Answer 3

Complete separation of the articular surface of a joint

Question 4

What is a fracture dislocation?

Answer 4

A dislocation where there is also a fracture involving one or more articular surfaces of a joint

Question 5

What is a sprain?

Answer 5

Stretching of the joint capsule and ligaments of a joint, insufficient to produce subluxation or dislocation

Question 6

What factors can contribute to fracture?

Answer 6

Strength of bone (weak bone e.g. due to osteoporosis or pathology such as metastasised tumours)
Force (excess force or normal force to a weak bone)

Question 7

What are the clinical signs and symptoms of a fracture?

Answer 7

Pain 
Swelling 
Tenderness
Bruising 
Deformity
Crepitus 
Abnormal movement

Question 8

How does fracture cause pain?

Answer 8

No nerves in bones but surrounding nerves

Bleeding can also cause pain due to increased pressure (within compartment)

Question 9

What is a compound fracture?

Answer 9

Fracture where skin has been breached

Can be from within (e.g. tibia breaking skin) or from without (external source - trauma)

Question 10

What is delayed union?

Answer 10

Fracture takes longer to heal than expected

Question 11

What is a non-union?

Answer 11

Fracture fails to reunite

Question 12

What is mal-union?

Answer 12

Fracture heals in wrong alignment (can cause deformity and weakness)

[Nb. common in humerus fractures]

Question 13

What is the process for diagnosing a fracture?

Answer 13

1. History and examination
2. Standard X-ray
3. Can use CAT scan or MRI if necessary
4. Ultrasound
5. Bone scan can be used if necessary (e.g. if fracture is failing to heal)

Question 14

When is CAT scan useful in diagnosing fractures?

Answer 14

Useful for soft-tissue injury as well as bone

Question 15

When is MRI useful in diagnosing fractures?

Answer 15

Useful for seeing surfaces of bone, blood supply and fluid in joint

Question 16

When is ultrasound useful in diagnosing fractures?

Answer 16

Useful for fractures in children

Question 17

What complications can occur with pelvic fractures?

Answer 17

Blood loss (veins unable to contract to prevent blood loss unlike arteries) 
Abdominal injury (esp. colon or bladder/ urethra) 
Nerve damage

Question 18

How is the ilium most commonly damaged?

Answer 18

Lateral blow

Question 19

Which group of patients most commonly fracture the pubic ramus?

Answer 19

Elderly patients (esp. if osteoporotic)

Question 20

What should be prioritised in pelvic injuries? **

Answer 20

Maintenance of pelvic ring (sacroiliac joints to pubic symphysis)
Commonly injured together

Question 21

What is a subcapital fracture?

Answer 21

Intracapsular NOF# where fracture line extends through the junction of the head and neck of femur

Question 22

What causes a short, externally rotated leg in NOF fractures?

Answer 22

Contraction of gluteal muscles

Question 23

What is the timeframe for reducing a NOF fracture?

Answer 23

Within 6 hours

Question 24

What can cause tibial shaft fractures?

Answer 24

Direct trauma

Rotational strain

Question 25

How can tibial shaft fractures be treated?

Answer 25

External or internal immobilisation

Prevent rotation with metal rod and screws through tibia (or metal plate if fragmented)

Question 26

What is compartment syndrome and what are the 5 Ps used to identify this?

Answer 26

Increased pressure within compartment - pressure within fascia greater than systolic pressure
5 Ps: increasing pain, pallor, parasthesia, pulselessness, paralysis

Question 27

What fractures can occur at the ankle joint?

Answer 27

Lateral malleolus

Medial malleolus

Question 28

How does a ruptured achilles tendon occur?

Answer 28

Cannot happen to a healthy tendon

Degeneration occurs first (due to damage to synovial sheath)

Question 29

How is a ruptured Achilles tendon diagnosed?

Answer 29

Simmond’s Test - squeeze calf - no movement of foot if Achilles tendon is ruptured
Ultrasound

Question 30

What is the treatment for a ruptured Achilles tendon?

Answer 30

Conservative - plaster/ immobilisation

Operative - tendon repair