Grade 1 or 2 ACL injuries do not usually need surgery. Conservative management (bracing and physiotherapy) is generally the best option for these kinds of injuries. However, surgery may be indicated if the rotational instability (instability with twisting movements) doesn’t improve. If the medial collateral ligament and medial meniscus were also injured (also known as an “unhappy triad of the knee”) you may also need surgery to repair the other injured structures.
In a grade 3 ligament tear (complete rupture of the ligament) the torn sections cannot re-attach by itself. Surgery is your best option and arthroscopy is the way to go as it is a minimally invasive technique. An ACL can’t be sutured back together, so the surgeon uses a technique called tissue graft.
They may harvest the hamstrings, patella tendon or the adductors to create an artificial tendon attached to the femur, which is like a scaffolding for the ligament to grow on.
This allows the body’s natural form of healing to take place. In the case of a complete ACL rupture, there are usually other structures involved, like the medial meniscus, thus an arthroscopic procedure allows the surgeon to investigate and repair these structures at the same time.