Anterior cruciate ligament (ACL) is one of the four major ligaments of the knee that connects the femur (thigh bone) to the tibia (shin bone) and helps to stabilise the knee joint. The ACL prevents excessive forward movement of the tibia in relation to the femur, as well as limits rotational movements of the knee. Injury to this ligament creates instability, stopping you from performing your daily activities.

ACL tears usually occur in young active patients during non-contact activities. An ACL can be injured in several ways:

• Sudden change in direction

• Abrupt stop when running

• Incorrect landing technique

• Direct blow to the side of your knee, such as during a rugby or soccer tackle

Symptoms When you injure your ACL, you might hear a loud “pop” sound and the knee will give way, forcing you to fall. Within minutes, your knee will swell due to bleeding from vessels within the torn ligament. If the lesion is not treated, the knee will feel unstable, especially when trying to change direction during sporting activities.   Diagnosis An ACL injury can be diagnosed with a medical history and a thorough physical examination of the knee. Diagnostic tests such as X-rays and MRI scans are requested. Physical examination may not be possible to complete due to pain. In this scenario, a second visit will be organised after a few weeks, once the acute phase subsides.   Treatment People can do a wide range of physical activities without a functional ACL. For this reason, treatment can be non-operative or operative, depending on your goals and symptoms. Initial treatment consists of rest, ice, compression and elevation. You may require crutches to mobilise if the pain affects your walk. Analgesics and anti-inflammatory medication will be recommended. It is important to control the pain and recover the range of motion. A Physiotherapist will assist you with this. Muscle strengthening is mandatory to compensate for a deficient ACL. Lifestyle modifications will be recommended if you do not wish to undergo a surgical treatment. Surgery: if you want to be able to go back to pivoting and contact sports, or if the knee keeps giving way on you, an ACL reconstruction will be recommended. This is performed with keyhole surgery and using one of your hamstring tendons, part of your patellar tendon or a tendon from a donor.