What is a LCL Injury?

The knee has four main ligamentous structures that act to stabilise the joint and limit excess movement. One of these ligaments is known as the Lateral Collateral Ligament, or the LCL for short. The LCL runs over the outside of the knee and attaches the thigh bone (femur) to the bone found on the outside of the shin (the fibula). Due to its attachment points on the outside of the knee, the role of the lateral collateral ligament is to prevent the knee from collapsing outward (this is known as lateral, or varus collapse).

It is quite unusual to see an isolated lateral collateral ligament injury (these represent less than 2% of total knee injuries). A direct blow to the inside of the knee, forcing it to bend outwards is the most common mechanism for this type of injury. In some scenarios, hyperextension of the knee joint has also been known to harm the LCL. Because of the force required to damage a lateral collateral ligament, it is common to see anterior cruciate ligament, posterior cruciate ligament and other associated injuries simultaneously.

What are the Signs and Symptoms of a LCL Injury?

+ Pain, swelling and tenderness over the outside of the knee

+ Due to the swelling & inflammation, knee range of motion is reduced

+ Feel of instability in the knee

+ Pain with twisting and turning the knee

What is the Treatment of LCL Injuries?

The treatment of a Lateral Collateral Ligament injury is dependent on the grade of injury sustained. LCL injuries are graded from I to III, with grade I injuries involving a stretching of the ligamentous fibres. A partial tear of the LCL is considered a grade I or II injury, while a grade III injury describes a complete rupture of the ligament.

Grade I & II Lateral Collateral Ligament injuries are managed conservatively. This can involve bracing the knee in a particular range of motion for a period of time, as well as specific exercises prescribed by your physiotherapist. It can take at least 6-8 weeks to return to sport after an injury of this nature.

A grade III injury, or complete rupture of the Lateral Collateral Ligament is generally managed surgically, with a graft taken from one of the hamstring tendons.