The anterior cruciate ligament (ACL) is a short sick ligament inside the knee joint that prevents the shinbone sliding forward from the thighbone. It is a common Lee injured ligament within the knee in athletes and other people who partake in sports, such as football, skiing, and rugby.
The mechanism of injury for the ACL is usually a rotational movement, often times when there is no external contact. Think of Michael Owen when he slapped his ACL playing football, he decelerated and tried to change direction and his knee buckled underneath him. Another mechanism of injury would be in a skier whose ski get stuck in the snow and causes them to twist their knee.
People who snap their ACL normally experience a popping sensation within the knee at the time of injury. There is often a rapid swelling that develops in the knee, within one or two hours after the injury. There is also initial severe pain that can settle down to a less severe pain. People are often able to walk around relatively normally, although in some discomfort. There is also a reduced range of movement in the knee with a lack of end range kneebends and needs straightening. Patients will also describe collapsing of the knee. For example, you could be getting out of a car and the knee suddenly gives away and you end up on the floor wondering what just happened.
If you have experienced a knee injury, heard a pop in the knee, had quite rapid swelling and now the knee is on stable you are best visiting a sports physio therapist to assess the knee. There are certain tests that can be done on the knee that indicate the knee ligament is snapped after which you will be referred onto a new consultant who will MRI the need to confirm the diagnosis.
There are two treatment options. The first one is just to leave the knee alone and see if you can manage with rehabilitation, and making the Nice strong and stable. This is the preferred line of treatment if you are fairly inactive. However, if you are fairly active you will be offered surgery to fix the knee ligament.
There are two main types of surgery to fix the ACL. Surgeons will either take the patella tendon from the affected me and put that inside the knee joint, making your new ligament or more commonly they will take a hamstring tendon from the affected leg and put that inside the knee joint as your new ACL.
You can expect six months of rehabilitation after surgery until your knee is back to normal and you are back to most sports. If you are planning on playing rugby or going skiing after an ACL operation you probably need to add a couple more months of strength training as these are fairly rigourous sports.
During your ACL surgery rehabilitation importance should be given to strengthening the vastus medialis and hamstring muscles, which are the key muscles to prevent this type of injury happening again.
You need to work on range before you work on loading than me especially gaining end of range flexion and extension. You also need to make sure you include proprioceptive training for 5-10 minutes before every strength training session to prevent further occurrence of this type of injury and to help potentiate the contractile force during the strength training.