<p>Surgery for a blown anterior cruciate ligament (ACL) inside the knee is becoming more and more common. New techniques to perform the surgery are on the rise across the country.</p><p>Damaged ACLs that were replaced using a double-bundle technique during surgery were as stable as patients who received the single-bundle technique, according to a study presented at a conference.</p><p>In double-bundle, the new ligament has two parts whereas the single bundle just has one.</p>