ACL Injuries

Causes of ACL injuries

ACL tears and sprains are normally the result of landing heavily from a jump, stopping very suddenly, quickly changing direction, slowing down after running fast or a heavy collision or direct impact on the knee. This type of injury is graded according to its severity. A grade 1 ACL sprain means the ligament has been slightly stretched but is still effective at keeping the knee joint stable. If you have a grade 2 ACL sprain, your ligament has been so stretched that it is loose and partially torn. The most severe ACL injury is a grade 3 sprain – referred to as a complete ligament tear. With a grade 3 injury, your ligament has been pulled off the knee or torn in half, leaving your knee joint unstable. Most of the ACL injuries we treat are grade 2 and 3 sprains.

You are at greater risk of an ACL injury if you have poor technique or ill-fitting footwear. Playing on artificial turf also increases the chance of becoming injured.

Symptoms of ACL injuries

At the time of the injury, your knee may give way and you might experience a popping sensation within the joint. Symptoms will vary in severity according to how badly sprained your anterior cruciate ligament is, but the primary symptom is pain in your knee which may be severe. Over time the pain may ease but if you return to exercising before the ligament is fully healed, you risk knee instability and more serious damage to the joint. With an ACL injury, it will be uncomfortable to walk and you may lose full range of motion in your knee. The joint will feel swollen and tender.

Diagnosis of ACL injuries

Your doctor will carry out a physical examination and ask how the injury occurred. You may be given an X-ray to check whether there are any fractures. An MRI scan provides a detailed image of the soft tissues including your ACL. It is not essential for diagnosing an ACL sprain, however, it can identify if there is accompanying damage to other soft tissues such as your meniscus or cartilage.

Treatment of ACL injuries

The treatment you are offered depends on the severity of your ACL injury and other factors. In younger patients who are involved in high impact sports, surgical repair is normally recommended to allow a return to return to sporting activities. However, if you are older or not intending to make a full return to sports, your surgeon may recommend non-surgical treatment alongside modifying your lifestyle. Your orthopaedic surgeon will discuss the options with you following a diagnosis.

Physiotherapy will help you to regain strength and flexibility in your knee following an ACL injury and, if you return to competitive sports, a professional training programme may help to reduce the risk of becoming injured again. You should also ensure you wear the correct footwear and padding. If you are skiing, ensure your ski bindings are correctly adjusted by a trained professional.

Unfortunately, if you injure your ACL you are at greater risk of developing knee osteoarthritis, even if you undergo surgery to reconstruct the ligament. Your surgeon will discuss ways to minimise the risk of going on to develop arthritis, which may include less intensive training after treatment.