Based on your history, physical examination and current symptoms your doctor is recommending that you have an ACL or anterior cruciate ligament reconstruction. The ACL is an important band of fibers in your knee that provides support for your normal knee functions. The goal of ACL reconstruction is to replace a torn or damaged ACL.
You have most likely torn your ACL because of an extreme twisting motion or hyperextension of your knee. A twisting injury may have also damaged or affected other ligaments or cartilage in your knee. Since the injury, you have probably been experiencing sensations of an unstable knee or of your knee giving out, making it difficult to pivot or straighten out your leg.
Once an ACL tear is suspected, possible treatments include medication, activity level changes and physical therapy. However, since these treatments have not been successful, your doctor feels that an ACL reconstruction is appropriate for your particular situation.