Anterior cruciate ligament (ACL) tears are among the most common serious knee injuries in sport, often requiring a period of rehabilitation and, in many cases, surgical reconstruction.
What is the ACL?
The anterior cruciate ligament is one of the main stabilising ligaments of the knee, running diagonally through the middle of the joint. It controls forward movement of the shin bone relative to the thigh bone and helps stabilise the knee during pivoting, cutting and landing movements.
Causes and Risk Factors
Most ACL tears occur during sports that involve sudden changes of direction, pivoting, jumping or landing, such as football, basketball and skiing. The injury often occurs without any contact from another player, typically when the foot is planted and the knee twists.
Symptoms
- A popping sensation at the time of injury
- Rapid swelling within hours of the injury
- A feeling of instability or the knee giving way
- Difficulty continuing sport or bearing weight
Diagnosis
Diagnosis is based on the mechanism of injury, clinical examination tests that assess knee stability, and MRI imaging, which confirms the tear and identifies any associated injuries to the meniscus or cartilage.
Treatment Options
Treatment depends on the degree of instability, associated injuries, and the patient’s activity level and goals. Some patients, particularly those with lower activity demands, may do well with structured physiotherapy and activity modification alone. Patients wishing to return to pivoting sports, or those with ongoing instability, are usually advised to undergo ACL reconstruction, where the torn ligament is replaced with a tendon graft.
Recovery
Rehabilitation after ACL reconstruction is a lengthy process, generally taking nine months to a year before a safe return to competitive pivoting sport, guided by achieving strength and functional milestones rather than time alone. Please see our Rehabilitation Protocols section for general post-operative guidelines.
This article is intended for general information only and does not replace a personal consultation. If you have experienced a knee injury, please arrange an appointment for an individual assessment.