Knee

Question 1

What causes fractures of the femoral shaft?

Answer 1

High velocity trauma (young and healthy)

Low velocity injuries (elderly with osteoporotic bones)

Question 2

What may a femoral shaft fracture look like?

Answer 2

Proximal fragment (abducted and flexed)
Distal fragment (varus and extended)

Tense swollen thigh 
Hypovolaemic shock (due to blood loss)

Question 3

How are distal femoral fractures caused?

Answer 3

Sporting injury with displacement (young)

Osteoporotic bones with fall from standing (elderly)

Question 4

Why is reduction essential in a distal femoral fracture?

Answer 4

The popliteal artery may become involved

Question 5

What causes tibial plateaued fractures?

Answer 5

High energy

Tibial loading with excess rotation of the knee

Question 6

What are complications of tibial plateau fractures?

Answer 6

Post traumatic osteoarthritis

Associated meniscal tears and ACL injuries

Question 7

What causes patella fractures?

Answer 7

Direct impact injury

Eccentric contraction of quadriceps

Question 8

How does an patella fracture appear on examination?

Answer 8

Palpable defect

If extensor mechanism disrupted then unable to perform leg raise

Question 9

What causes patella dislocations?

Answer 9

Twisting injury with slight flexion
Direct blow to knee

Most common direction is laterally

Question 10

What are common predispositions to patella fractures?

Answer 10

Ligament laxity 
Weakness of quadriceps muscles (VMO)
Shallow trochlea 
Long patella ligament 
Previous dislocations

Question 11

What is the treatment for patella dislocations?

Answer 11

Extending the knee and reducing the patella
Immobilisation
Physio to strengthen the VMO

Question 12

How do meniscus injuries occour?

Answer 12

Sudden twisting of weight bearing knee when in high flexion

Question 13

How does a meniscus tear present?

Answer 13

Intermittent pain localised to joint line
Clicking and locking of knee
Delayed swelling

Restricted motion
Loose meniscus fragments can act as a block to motion

Question 14

How are meniscus tears treated?

Answer 14

If from actuate injury surgery to replace/ repair

If chronic degeneration, conservative management

Question 15

What is the unhappy triad?

Answer 15

Injury to ACL, medical collateral ligament and medical meniscus
Due to strong force applied to knee on lateral aspect

Question 16

What causes ACL injuries?

Answer 16

Quick deceleration and hyperextension OR rotation
Or force to back of knee when flexed

Feel a popping sensation

Question 17

How do ACL injuries present?

Answer 17

Immediate swelling
Instability of the knee

Rotational instability as tibia rotates with PLC

Question 18

How are PCL injuries caused?

Answer 18

Flexed knee with large force to upper tibia (dashboard injury)
Falling on flexed knee with foot plantar flexed

Question 19

What test would you do for an ACL injury?

Answer 19

Anterior draw test

Lachman’s test

Question 20

What test would you for a PCL injury?

Answer 20

Posterior draw test

Question 21

How are knee dislocations caused?

Answer 21

High energy trauma uncommon injuries)

Question 22

What often accompanies a dislocated knee joint?

Answer 22

Damage to 3 out of 4 of the ligaments (MCL,LCL,ACL,PCL)

Damage to popliteal artery (as artery immobile)

Question 23

What is Housemaid’s knee a swelling of?

Answer 23

The pre-patella Burris

Question 24

What causes housemaids knee?

Answer 24

Repetitive trauma to the bursa

Question 25

What is clergyman’s knee also known as?

Answer 25

Infrapatellar burtisis

Question 26

What causes clergyman’s knee?

Answer 26

Micro trauma from the more upright position if kneeling

Question 27

What is a popliteal cyst or bakers cyst a swelling of?

Answer 27

Semimembranosus bursa

Question 28

What causes a popliteal cyst?

Answer 28

Fluid accumulating as an indirect consequence of swelling within knee joint
If effusion in knee joint can force its way to posterior capsule

Question 29

What causes suprapatellar bursitis?

Answer 29

A knee effusion
As bursa extension of synovial cavity of knee
Indicates a more significant pathology

Question 30

What causes effusion of the knee?

Answer 30

Osteoarthritis 
Rheumatoid arthritis 
Infection 
Gout 
Repetitive micro trauma

Question 31

What is Osgood-Schlatter’s disease?

Answer 31

Inflammation of insertion of patella ligament into tibial tuberosity
Causes localised pain and swelling (especially on exercise)

Question 32

What are the symptoms of knee osteoarthritis?

Answer 32

Stiffness
Swelling
Pain (fluctuating levels, worsening by activities, worsened after rest)

Deformity of the knee
Crepitus (as articular surface worn away)
Effusion may develop (limit movement)

Question 33

Why does the knee feel like its giving way in OA?

Answer 33

Weakened quadriceps muscles (joint instability)

Question 34

What is septic arthritis of the knee?

Answer 34

Invasion of joint space by microorganisms.

Differs from reactive which is sterile inflammation resulting from extra-articular infection

Question 35

What is the most common cause of septic arthritis?

Answer 35

Staph aureus

Question 36

What increased your risk of septic arthritis?

Answer 36

Having prosthetic joint
(Intra operative infection or spread from distant site)

Cement used inhibits wbc growth

Question 37

What is the main consequence of bacterial invasion?

Answer 37

Damage to articular cartilage
By;
-pathogens properties
-hosts immune response

Question 38

What are the signs of septic arthritis?

Answer 38

Fever
Pain/ redness
Produced range of motion