LIGAMENT INJURIES OF THE KNEE

The knee has a complicated system of ligaments that act as passive stabilisers of the joint. When the knee is put under undue stress some of these ligaments can partially or completely tear. We have a mild sprain one end of the spectrum and complete tear of the ligament on the other. The main ligaments of the knee are the two cruciate ligaments inside the joint and the two collateral ligaments on either side. The medial patello-femoral ligament stabilises the kneecap so it does not dislocate when bending the knee. Besides the ligaments the meniscus (sports cartilage) and the muscles with their respective tendons around the knee also contribute to the stability of the joint.
The knee ligaments can tear in isolation or in combination depending on the injury. It is common to have meniscus and cartilage surface injuries along with the ligament tear.

This is by far the most common ligament injury in the knee that requires surgical treatment. It is uncommon for the ACL to tear only partially and once torn it cannot heal leaving the knee unstable. It may require keyhole surgery to restore the stability of your knee. You can find out more here.

The MCL is a broad ligament on the inner side of the joint. This is the most common ligament injury around the knee which is caused by a knock from the outer side.  The MCL usually tears only partially.

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• Symptoms: you may feel a pop at the time of the injury with pain and swelling on the inner side of the knee

• Diagnosis: based on the typical history and symptoms. An x-ray should exclude any bone damage. An MRI scan will confirm extent of the tear of the ligament and can show any other damage to the rest of the knee.

• Treatment: if torn in isolation the MCL tear can be treated in a brace and should heal in about 6 weeks. Sometimes a niggling pain lingers for a few months which may indicate a chronic sprain. This responds well to a steroid injection. 

The LCL is a chord-like ligament which stabilises the outer side of the joint. It usually tears along with other structures  collectively called the postero-lateral corner. Postero-lateral corner injuries in turn are usually associated with the tear of the posterior cruciate ligament (PCL) or the ACL. This injury is usually caused by a combination of twisting and a knock from the inner side.​​

• Symptoms: you may feel a pop at the time of the injury with pain and swelling.

• Diagnosis: based on the typical history, symptoms and clinical examination. An x-ray should exclude any bone damage. An MRI scan will confirm extent of the tear of the ligaments and can show any other damage to the rest of the knee.

• Treatment: the postero-lateral structures do not heal well on their own and as they are usually associated with other ligament injuries  resulting in significant instability, a multi-ligament reconstruction is necessary to restore knee function.

The PCL is strong ligament in the middle of the knee just behind the ACL. Its main function is preventing any excess backwards shift of the the shin relative to the thigh bone. Its tear is much less common then the ACL's, but it is often associated with other ligament tears. This injury is usually caused by a combination of twisting and a knock from the front.​​

• Symptoms: you may feel a pop at the time of the injury with pain and swelling.

• Diagnosis: based on the typical history, symptoms and clinical examination. An x-ray should exclude any bone damage. An MRI scan will confirm extent of the tear of the ligaments and can show any other damage to the rest of the knee.

• Treatment: an isolated PCL tear may heal if treated correctly from the outset. You will need a brace and physiotherapy. The recovery may take 3-6 months. In a multi ligament injury situation or if your knee is still unstable after conservative treatment you will need a PCL reconstruction.