Ligament rupture

Question 1

What are the 3 grades of knee ligament injury?

Answer 1

• Grade 1 - sprain - tear some fibres, but macroscopic structure in tact
• Grade 2 - Partial tear - Some fascicles disrupted
• Grade 3 - Complete tear

Question 2

What the main ligaments that can be rupture in the knee?

Answer 2

ACL
PCL
MCL
LCL

Question 3

What is the ACL?

Answer 3

Anterior Cruiciate Ligament

Question 4

What is the MCL?

Answer 4

Medial Colateral Ligament

Question 5

What is the PCL?

Answer 5

Posterior Colateral Ligament

Question 6

What is the LCL?

Answer 6

Lateral Colateral Ligament

Question 7

What is the function of the ACL?

Answer 7

The ACL resists anterior subluxation of the tibia and internal rotation of the tibia in extension

Question 8

How are ACL ruptures mostly caused?

Answer 8

It is often caused by a twisting sports injury, with the upper body turning laterally on a planted foot

Question 9

Who is most at risk of ACL rupture?

Answer 9

Females

Question 10

How will an ACL tear present?

Answer 10

There is usually a classic presentation of a sports injury with a “pop”

There is also often haemarthrosis and giving way of the leg when turning as ACL rupture may lead to rotatory instability

Question 11

What clinical tests can be used in ACL tests?

Answer 11

Anterior drawer test
Lachmann test

Question 12

What investigations are used in ACL rupture?

Answer 12

MRI
Joint aspiration (Haemarthrosis)

Question 13

What are the 3 possible outcomes of ACL management?

Answer 13

• 1/3rd compensate and can function well
• 1/3rd can avoid instability by avoiding certain activities
• 1/3rd do not compensate and have frequent instability or cant get back to high impact sport

Question 14

How are most ACLs managed?

Answer 14

Time and physiotherapy

Question 15

When is surgery indicated in ACL rupture?

Answer 15

Surgery is indicated in cases where rotatory instability is not responding to physio, to protect meniscal repair or in athletes who do not want to give up high impact sport

Question 16

What surgery is is most commonly used in ACL rupture?

Answer 16

In cases where stabilising surgery is required, often grafting from the hamstring tendons or patellar tendons is performed

Question 17

What is the rehab period for surgery in ACL rupture?

Answer 17

There is a 3 month to 1 year rehab period, with around a 20% failure rate

Question 18

What is the function of the MCL?

Answer 18

The MCL resists valgus stress (Abduction of the knee)

Question 19

What is the most common mechanism for MCL rupture?

Answer 19

This is usually caused by extreme valgus (abductory) stress with possible external rotation, such as from a rugby tackle from the side

Question 20

How will MCL rupture usually present?

Answer 20

• Knee swelling
• Ecchymosis
• Pain
• Deformity
• Valgus instability

Question 21

What are some clinical signs of MCL rupture?

Answer 21

Tenderness over MCL origin or insertion
Pain and laxity on valgus stress

Question 22

How will MCL rupture be most commonly managed?

Answer 22

Conservatively:
- Early bracing
- Early motion
- Physiotherapy

Question 23

How is a diagnosis of MCL rupture made?

Answer 23

Isolated MCL tear is a clinical diagnosis, but X-rays and MRI can be used to rule out other associated injury

Question 24

What surgery can be carried out in MCL rupture?

Answer 24

Reconstruction with tendon grafting

Question 25

What is the function of the PCL?

Answer 25

Resists posterior subluxation of the tibia

Question 26

What is the most common cause of PCL rupture?

Answer 26

PCL rupture is often caused by a direct blow to the anterior tibia (dashboard, motorbike, fall) or hyperextension injury

Question 27

How will PCL tear usually present?

Answer 27

This will present with knee pain and bruising, as well as possible recurrent hyperextension or instability descending stairs

Question 28

What clinical test can be used to test for PCL rupture?

Answer 28

Posterior drawer test

Question 29

What investigations are required in PCL rupture diagnosis?

Answer 29

X-ray
MRI

Question 30

When may surgery be required in PCL rupture?

Answer 30

If the patient develops instability

Question 31

What is the function of the LCL?

Answer 31

This resists varus stress (Adduction of the knee)

Question 32

What is the most common cause of LCL rupture?

Answer 32

This often occurs as part of a multi-ligament injury

They are usually caused by varus injury with hyperextension

Question 33

How will LCL rupture present?

Answer 33

• Knee swelling
• Ecchymosis
• Pain
• Deformity

Question 34

What are some clinical signs of LCL rupture?

Answer 34

Pain and tenderness over LCL origin and insertion
Pain and laxity on varus stress

Question 35

How is LCL rupture diagnosed?

Answer 35

Isolated LCL tear is a clinical diagnosis but x-rays and MRI can be used to rule out associated injuries

Question 36

How does early presentation of LCL tear need treating?

Answer 36

The LCL does not heal and can cause instability

Complete rupture needs urgent repair within 2-3 weeks of injury

Question 37

How will later presenting LCL tear be treated?

Answer 37

Reconstruction with tendon grafting

Question 38

What is a possible complication of LCL rupture?

Answer 38

Common fibular nerve palsy

Question 39

What is the posterolateral corner?

Answer 39

This is a group of muscles consisting of the PCL, LCL, popliteal and other small ligaments which resist external rotation of the tibia in flexion

Question 40

How will posterolateral corner rupture present?

Answer 40

Varus and rotatory instability