The anterior cruciate ligament, most commonly known as the ACL, is one of the four primary ligaments of the knee and is frequently injured. It is located in the center of the knee and its function is to prevent the tibia or shin bone from moving forward relative to the femur or thigh bone at the knee.
When a person has a new ACL injury, they may feel a “pop” in the knee and experience pain and swelling. The knee may feel unstable or give out. Injuries frequently occur as a result of a twisting injury during a sporting activity but can occur during non-sporting activities as well. Other injuries are commonly associated with ACL tears, such as meniscus tears, cartilage damage, bone contusions, and other ligament injuries.
ACL tears can be full (complete) or partial. A complete tear is more common. The type of tear and the other associated injuries are very important factors in selecting the appropriate treatment. The patient’s individual characteristics, such as age, occupation, current activity level, expectations for future activity, other health issues, and level of functional disability from the injury are also important when making a treatment plan.
The patient and the doctor need to work together to carefully diagnose and determine the extent of the injury to the knee and look at the patient-specific factors to jointly formulate the best treatment plan. The decision-making process can be quite complex and partnering with a knowledgeable and experienced sports medicine surgeon is crucial to getting the best outcome possible.
ACL injuries can be treated both with and without surgery. In many cases, younger and more active patients are more likely to have surgical treatment. Patients with frequent giving way of the knee during minor activity may also choose surgery. After the diagnosis is made, the patient usually treats the knee with ice, elevation, range of motion exercises, and strengthening. Regardless of the treatment chosen, these are important first steps. If nonsurgical treatment is chosen and the knee functions well after initial treatment, nothing more may need to be done. However, if symptoms of instability persist despite nonsurgical treatment, ACL reconstruction is often the best treatment.
There are many different ways to surgically treat an ACL tear and there are pros and cons to each. Most commonly, the ligament is reconstructed with another piece of tissue, either from the patient or from a tissue donor. This tissue then eventually becomes a new ACL. In rare circumstances, the ligament may be repaired or sewn back to the bone.
Reconstruction is by far the most common surgical treatment and has been well studied, with good results. The type of tissue or graft chosen is very patient-specific, and your surgeon should be well versed in several different options to give the best result. Usually young and athletic patients will choose to use their own tissue, which is called an autograft. Some typical options include using the patella tendon with patella and tibia bone on each side; this is termed a BPTP graft. The patient’s hamstring tendons may also be used, and more recently, the quadriceps tendon may be used. When tissue from a tissue donor is selected, many different options are possible and these are termed allografts.
At the time of your surgery, you will likely be put under general anesthesia and an injection of local anesthetic (nerve block) may be used to help with pain control after surgery. An evaluation of your knee while under anesthesia will take place to confirm instability. Two or more small incisions will be made in your knee to insert a camera called an arthroscope, and a variety of instruments will be used to perform the necessary procedures inside your knee.
Your meniscus and cartilage will be evaluated for injuries, as the MRI may not pick up all of the damage, and injuries to those structures will be addressed. The ACL will be assessed and the damaged section removed. New attachment sites will be made in your bone for the graft to fit into. The graft will be harvested in the case of an autograft, and the autograft or allograft will then be placed into the bone sites. At the conclusion of your procedure, the stability of your knee will be checked. Surgery typically takes one to two hours, depending on how much other damage is found. You will spend one to two hours in the recovery room and then go home.
You can usually move your knee at home and may be able to put some weight on it, but your doctor will give you postoperative instructions that are individualized for you. Pain medicine will also be provided.
Rehabilitation after ACL surgery depends on the patient and what their activity expectations are, ranging from a home program to an extensive athletic rehabilitation program. In general terms, the patient can progress their activities in a supervised fashion and return to athletics in 6 to 12 months. It is important to know that not all athletes return to their previous level of activity, even when surgery is considered successful. The patient, at times, can re-injure the knee and even tear the ACL in their other knee. Patients can develop arthritis in the knee because of the injury, and problems may result if meniscus or cartilage damage was present from the injury.
To find out if ACL reconstruction is right for you, schedule an appointment with one of our joint preservation surgeons by calling 888-660-2663 or complete the appointment request box.