Ligament rupture Flashcards
What are the 3 grades of knee ligament injury?
- Grade 1 - sprain - tear some fibres, but macroscopic structure in tact
- Grade 2 - Partial tear - Some fascicles disrupted
- Grade 3 - Complete tear
What the main ligaments that can be rupture in the knee?
ACL
PCL
MCL
LCL
What is the ACL?
Anterior Cruiciate Ligament
What is the MCL?
Medial Colateral Ligament
What is the PCL?
Posterior Colateral Ligament
What is the LCL?
Lateral Colateral Ligament
What is the function of the ACL?
The ACL resists anterior subluxation of the tibia and internal rotation of the tibia in extension
How are ACL ruptures mostly caused?
It is often caused by a twisting sports injury, with the upper body turning laterally on a planted foot
Who is most at risk of ACL rupture?
Females
How will an ACL tear present?
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
What clinical tests can be used in ACL tests?
Anterior drawer test
Lachmann test
What investigations are used in ACL rupture?
MRI
Joint aspiration (Haemarthrosis)
What are the 3 possible outcomes of ACL management?
- 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
How are most ACLs managed?
Time and physiotherapy
When is surgery indicated in ACL rupture?
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
What surgery is is most commonly used in ACL rupture?
In cases where stabilising surgery is required, often grafting from the hamstring tendons or patellar tendons is performed
What is the rehab period for surgery in ACL rupture?
There is a 3 month to 1 year rehab period, with around a 20% failure rate
What is the function of the MCL?
The MCL resists valgus stress (Abduction of the knee)
What is the most common mechanism for MCL rupture?
This is usually caused by extreme valgus (abductory) stress with possible external rotation, such as from a rugby tackle from the side
How will MCL rupture usually present?
- Knee swelling
- Ecchymosis
- Pain
- Deformity
- Valgus instability
What are some clinical signs of MCL rupture?
Tenderness over MCL origin or insertion
Pain and laxity on valgus stress
How will MCL rupture be most commonly managed?
Conservatively:
- Early bracing
- Early motion
- Physiotherapy
How is a diagnosis of MCL rupture made?
Isolated MCL tear is a clinical diagnosis, but X-rays and MRI can be used to rule out other associated injury
What surgery can be carried out in MCL rupture?
Reconstruction with tendon grafting
What is the function of the PCL?
Resists posterior subluxation of the tibia
What is the most common cause of PCL rupture?
PCL rupture is often caused by a direct blow to the anterior tibia (dashboard, motorbike, fall) or hyperextension injury
How will PCL tear usually present?
This will present with knee pain and bruising, as well as possible recurrent hyperextension or instability descending stairs
What clinical test can be used to test for PCL rupture?
Posterior drawer test
What investigations are required in PCL rupture diagnosis?
X-ray
MRI
When may surgery be required in PCL rupture?
If the patient develops instability
What is the function of the LCL?
This resists varus stress (Adduction of the knee)
What is the most common cause of LCL rupture?
This often occurs as part of a multi-ligament injury
They are usually caused by varus injury with hyperextension
How will LCL rupture present?
- Knee swelling
- Ecchymosis
- Pain
- Deformity
What are some clinical signs of LCL rupture?
Pain and tenderness over LCL origin and insertion
Pain and laxity on varus stress
How is LCL rupture diagnosed?
Isolated LCL tear is a clinical diagnosis but x-rays and MRI can be used to rule out associated injuries
How does early presentation of LCL tear need treating?
The LCL does not heal and can cause instability
Complete rupture needs urgent repair within 2-3 weeks of injury
How will later presenting LCL tear be treated?
Reconstruction with tendon grafting
What is a possible complication of LCL rupture?
Common fibular nerve palsy
What is the posterolateral corner?
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
How will posterolateral corner rupture present?
Varus and rotatory instability
