Collateral Ligament Injuries
What is a collateral ligament injury and how do they get injured?
- Collateral ligaments of the knee are the ligaments which brace the sides of the knee joint.
- There is the Medial Collateral Ligament (MCL) and the Lateral Collateral Ligament (LCL).
- As with other types of ligament tears, collateral ligament injuries are categorised as a grade 1, 2 or 3 injuries, where grade 1 is slightly stretched and grade 3 is a complete tear or rupture.
- The MCL is more frequently damaged than the LCL due it being easier to create a valgus strain versus a varus strain.
- These are often triggered by contact sport injuries or by a twisting injury with the planted foot stuck to the ground.
What are the symptoms of a collateral ligament injury?
- Pain and swelling within a few hours of injury.
- If the MCL is involved, this is typically on the inside of the knee and an LCL injury is typically on the outside.
- Bruising may occur over the next few days
- Instability and the feeling of the knee giving way or the knee feeling loose.
- Surgical treatment may be advised if the patient wishes to return to a high level of function or it may be appropriate to test the injury in a knee brace.
How is a collateral knee injury diagnosed?
- The MRI can clearly show a collateral tear and helps assess if other ligaments are involved.
- X-Rays can’t detect damage to the ligament but can detect concurrent small breaks, where a small part of the bone attached to the ligament, pulls away from the main bone.
- This is called an avulsion fracture.
What are the treatments for collateral knee injury tears?
- In many cases surgery is not required. Treatments include anti-inflammatory medications and physiotherapy to improve knee function and application of a knee brace.
- Icing and bracing is important as the knee needs to be protected from the sideways force that caused the injury.
- To further protect the knee, you may be given crutches
- Most isolated collateral ligament injuries do not require surgery unless it is associated with other ligament injuries.