ACL Tear

The knee has four main ligaments, one of which is the anterior cruciate ligament (ACL). It is essential for maintaining stability in the knee and preventing exaggerated, damaging movements. A tearing injury to the ACL can result in instability and imbalance, interfering with sports and everyday activities. This can lead to accidents due to the knee 'giving out', and requires medical attention.

Symptoms

An ACL tear may initially result in pain to the knee and inflammation in the area. The knee might feel wobbly or unstable, but this can be harder to detect without a professional (depending on the severity of the tear). Sometimes these can be the most prominent symptoms, but a regular consequence of ACL tearing is a sports injury provoked due to the knee instability. This can occur at the time of tearing or later. A popping sound is often heard, followed by the knee giving out and collapsing beneath the athlete.

Causes

ACL tearing is usually a sports injury. In approximately 4 out of 5 cases the tearing is caused by a non-contact injury, meaning that there is no hard collision with a fellow competitor. Instead it is certain movements that mostly lead to the injury, especially landing badly from a jump or fall (as in high or long jumping) or using the knee as a pivot. Pivoting occurs when the athlete remains secure on the spot but turns or rotates the body using the knee. Outside of sport a car accident or incident at work is usually the cause. Gender can also be a factor, with women more likely to sustain an ACL tear than men.

Medical Treatment

The doctor will use a physical examination to assess the knee instability and torn ligament. They may also use an MRI or other scan to see the ACL tear and any additional knee injuries. A major tear will often require ACL reconstruction surgery for people who are active and dependent on their ACL, such as athletes participating in demanding sports with constant turning and pivoting (e.g. basketball, rugby, or football). The doctor will determine whether this is the best option or if more conservative measures are sufficient. The normal surgical procedure reconstructs the ligament with the aid of a different ligament or tendon. Around 90% of patients have successful surgery, but in some other cases it may not fully eliminate the problem, with the risk of knee complications such as rigidity and ongoing instability.

Rehabilitation

Post-operative rehab is crucial for complete recovery following an ACL reconstruction. This helps to build up flexibility, movement and strength in the area, while also safeguarding against future recurrence of the injury by increasing knee stability. The process will be gradual, as moving too quickly can lead to further injury. A doctor or therapist should guide you through the stages.