A Guide to Anterior Cruciate Ligament (ACL) Reconstruction

At Taos Orthopaedic Institute, we are genuinely concerned that our patients have a full understanding of their injury, treatment options, and the rehabilitation required for recovery. This handout is meant to complement the information you receive during your doctor’s visit. We encourage you to read this and to ask questions.

Taos Orthopaedic Institute is a center of excellence for sports medicine. Utilizing state-of-the-art diagnostic and treatment techniques, we offer a wide variety of conservative and surgical options for the patient with a torn anterior cruciate ligament. Our sports medicine orthopaedic surgeons have specialty training and extensive experience in reconstruction of the anterior cruciate ligament.

What is the Anterior Cruciate Ligament (ACL)?

The anterior cruciate ligament (ACL) is the central stabilizing ligament of the knee. Running through the knee from the front of the tibia (shin bone) to the back of the femur (thigh bone) it assists proper movement of the joint and prevents abnormal slippage of the bones. Abnormal slippage can create an unstable knee that “gives way” during activity.

How is the ACL injured?

While the ligament can be injured with a direct blow to the knee, it is more common to tear the ligament when pivoting or twisting on a planted food or by hyper extending the knee.

How do I know my ACL is torn?

Usually, a tear to the ACL results in sudden pain, giving way of the knee, or a combination of both. Many patient report having heard a “pop” when they injured their knee. The knee usually swells within 1-3 hours of the injury. A doctor can examine the knee and is usually able to identify any ligaments that are injured. The knee will feel loose and/or you will have muscle guarding during the examination.

Do I need x-rays, MRI’s or any other tests?

A set of x-rays is usually ordered to make sure that there are no broken bones in the knee. MRI’s can be helpful, but are not always needed when the doctor knows what is wrong just from examining you. MRI’s are obtained primarily to assess the extent of the damage to other structures including the menisci, joint surfaces and bone.

Is there usually other damage to the knee when the ACL is torn?

Other ligaments in the knee can be injured at the same time as the ACL. These may need to be repaired, but many times heal adequately without surgery.

The most common injury that occurs with the ACL tear is a meniscus tear. Some meniscus tears can be repaired and some can be trimmed back so that the torn edges are smooth. If the meniscus can be repaired, it is usually done at the time of the ACL surgery.

Another common injury that can occur with an ACL tear is damage to the cartilage on the joint surface. Damage to these surfaces is very serious and in some cases is the worst part of the injury. It may require more complex surgery which is usually done at the time of the ACL surgery.

Does a torn ACL have to be fixed with surgery?

The ACL cannot heal on its own, but not all tears of the ACL need to be fixed. This depends on age and your activity level. People under 40 years of age should have their ACL reconstructed to prevent arthritis. People participating in activities where they plant their feet and twist or cut are susceptible to having an unstable knee and may be better off with surgery. People with strenuous jobs may also need surgery. People who are unwilling or unable to modify their activities and desire an unrestricted lifestyle are encouraged to consider the surgery to have the best chance of returning to their previous lifestyle. Advances in arthroscopic surgery and an aggressive rehabilitation program contribute to an accelerated recovery for patients with ACL injuries.

On the other hand, people who lead a more sedentary lifestyle may be able to get by with exercise and a brace. However, even someone with a sedentary lifestyle may experience giving way with simple activities such as climbing or descending stairs or stepping off a curb. In these cases surgery is needed to restore normal every day activities and to prevent further damage to the knee.

If I don’t have my ACL fixed am I likely to hurt my knee again or get arthritis?

Even if the knee joint does not become unstable (give way) it will still be loose after an ACL injury. This leads to damage in other supporting structures, such as the medial and lateral collateral ligaments and the cushion pads called meniscus cartilages. In someone with a recent ACL injury, the risk of associated meniscus damage may be 30 to 40 percent. In someone who has had an ACL injury that has been present for years and who may have buckling episodes, the risk of associated meniscus damage is 90 percent. ACL and meniscus injury may contribute to the early onset of arthritis in your knee.

How is the ACL fixed?

The ACL is reconstructed with arthroscopic techniques. The arthroscope is a fiber optic instrument (narrower than a pen), which is put into the joint through small incisions. A camera is attached to the arthroscope and the image is viewed on a TV monitor. The arthroscope allows the surgeon to fully evaluate the entire knee joint. Small instruments ranging from 3-9 millimeters in size are inserted through additional incisions so that the surgeon can feel the various joint structures, diagnose the injury, and then repair, reconstruct or remove the damaged structure.

In ACL reconstruction a replacement graft is precisely positioned in the joint at the site of the former ACL and then fixed to the thigh and lower leg bones with screws. There are currently several options for replacement grafts and screws. Choices for the type of replacement graft include autograft (using your own tissue), allograft (donor tissue) and synthetic (artificial) grafts. Choices for the types of screws include inert metal screws and bio-absorbable screws.

Autografts can come from your patellar tendon, quadriceps tendon or the hamstring tendons. The graft choice to be used is determined by you and your surgeon. All of these graft options offer a strong graft, secure fixation and excellent long-term results. The results show that people are able to return to their activities with few complications. Since the graft comes from your own body there is no chance of infectious disease transmission or rejection.

Allografts are donor tissues taken from tissue banks. They also are strong grafts with excellent long-term results. Because the surgeon is not taking the tissue from your body, the surgical time and operative pain are less. This allows for easier rehabilitation in the early post-operative stages. Although there is a risk of infectious disease, donor tissue is received only from a reliable tissue bank. The tissue is rigorously screened and treated to prevent the spread of infectious disease. The risk of contracting infectious disease from an allograft is very small (less than one in eight million). Although rejection of the graft is possible, the risk of this is extremely low because the tissue is not living material.

Synthetic grafts are available for use in certain situations, but most are experimental and do not work as well as allografts and autografts.

Regardless of the graft material chosen, the most important aspect of surgery is that the ligament graft is placed and secured precisely. Accurate graft placement is essential for a good result and secure graft placement permits early, more aggressive rehabilitation after surgery.

What are some of the possible complications?

While complications are not common, all surgery has associated risks. Possible complications include excessive stiffness after the surgery or pain in the knee or under the kneecap. Your rehabilitation after surgery is specifically designed to address these issues. Other complications can arise from infection of the wounds, phlebitis, bleeding into the knee, and nerve injury.

What do I need to do to prepare for surgery?

Our staff will work with you to set up the surgery through your insurance company and will instruct you in matters that you will need to take care of concerning your insurance paperwork.

Prior to surgery you may be asked to perform some exercises at home or with a physical therapist to prepare for surgery. These exercises prepare the knee by decreasing the swelling, increasing the motion and maximizing the strength of your leg.

What type of anesthesia is used?

General anesthesia is used. An anesthetist is always present if there is a need for further sedation or pain control. The morning of surgery, an anesthetist will discuss with you the various options and answer your questions.

Because our surgeons are extremely experienced, the operation can be performed rather quickly. The shorter surgical time decreases the amount of anesthesia and limits side effects from the anesthesia.

How long will I be in the hospital?

Most people are able to have surgery and go home the same day. Occasionally, a night in the hospital is needed. How long you stay will depend on several factors including your age, health status, other damage in the knee, and the side effects of anesthesia.

What happens the day of surgery?

The day before surgery you will be told what time to report to the hospital the next day. It is very important to arrive on time. You will be admitted to the hospital and taken to a pre-operative area where you will be prepared for your surgery and then taken to the operating room.

Note: You may not eat or drink anything after midnight the night before your surgery. If you must take medicine then you will be permitted to do so with just a sip of water.

After the operation, you will be taken to the recovery room to be monitored. Here the staff will check that the effects of the anesthesia are wearing off properly and they will provide you with medication for any pain you are having. If you are going home the same day, you will be given specific instructions to follow at home and discharged after you have adequately recovered. If you have to remain overnight, you will be taken to your room when you are ready.

How should I care for my knee after surgery?

Prior to your discharge from the hospital you will be given specific instructions on how to care for your knee. It is important to follow these instructions. In general, you can expect the following:

Diet: Resume your regular diet as soon as possible.

Medication: You will be given a prescription for pain medication and an anti-inflammatory medication. Follow the directions from your pharmacy.

Bandage: You will have an elastic bandage from your foot to your thigh. There will be bulky dressings under the elastic wrap. Keep these on for two to three days after your surgery as instructed. Under these dressings you will have several small incisions with stitches. You may cover these with bandages after you remove the original dressing.

Brace: A post-operative brace is worn when walking for six weeks after surgery. A sports brace is then provided and recommended for pivoting sports.

Bathing: You will be able to shower within two to three days following surgery. Do not soak your operated leg in a tub or whirlpool for at least three weeks after surgery. The incisions are not fully closed and soaking the leg would increase the risk of infection. Once you have showered you should put the brace back on prior to leaving the shower.

Ice: Use ice over the knee. It is best to apply ice for 20 minutes at a time, usually three to four times per day. During the first two days after surgery, the heavy bandages may make it difficult for ice to penetrate. Do not leave the ice directly on your skin for extended periods as this may cause frostbite. DO NOT put heat on your knee.

Elevation: Keeping your leg elevated above the level of your heart will help with swelling and discomfort. DO NOT put a pillow directly under your knee as this encourages the knee to stay in a bent position. Instead, place the pillow under the calf and foot.

Continuous Passive Motion (CPM): To prevent difficulty moving the knee after surgery, a CPM Machine gently promotes early postoperative motion. This early movement of the knee also decreases swelling in the operated area. In most cases, a CPM will be provided to you before you are released from the hospital.

Crutches: Crutches are required for walking at first. Most patients use crutches for the first 7-14 days.

Follow-Up Office Visit: You will be instructed to follow-up at our office one and one-half weeks after your surgery. At this time, your stitches are removed, and your surgery is reviewed. You will be instructed on making further follow-up appointments at this time.

Exercise: You may be taught some exercises to do initially after surgery. After 1-½ weeks you are given a prescription for formal rehabilitation to do with a physical therapist.

Return to work or school: Most people are able to return to their jobs or school within 5-10 days. The exception to this is for people who have strenuous jobs that require them to be on their feet a lot, lifting objects, climbing or driving.

Driving: You should be able to drive within weeks after surgery. However, you should be aware that there might be laws pertaining to use of your car in the early postoperative period. If you are in a car accident and you knee is in a brace due to surgery, there may be legal implications. Also, you should not drive while you are taking narcotic analgesics.

What will rehabilitation involve? Rehabilitation begins the day after surgery. As the tissues heal, you will be permitted to do more and more activities. You will probably begin walking immediately after surgery with the postoperative brace. Your rehabilitation will be based on guidelines we have developed. In general we use an accelerated protocol, which is based on several goals: 1) early motion 2) early weight bearing and 3) regaining control of the leg muscles as soon as possible. Note that an accelerated program DOES NOT mean how soon you may return to activities. You will start out with very specific exercises and will be permitted to do more as you recover.

Preliminary Exercises – Early Postoperative Period: 0-1 Week

1. Isometrics:

Tighten muscles in front and back of thigh. Hold five seconds, relax. Repeat 10 times

an hour.

2. Straight Leg Raise:

Hip flexion – in brace, leg straight. Raise leg off bed approximately 12 inches. Hold

five seconds, relax. Repeat 10 times.

Hip abduction – in brace, leg straight. Lie on unoperated side, raise leg

approximately six inches off bed. Hold five seconds, relax. Repeat 10 times.

Hip adduction – in brace, leg straight. Lie on operated side, raise leg approximately

six inches off bed. Hold five seconds, relax. Repeat 10 times.

Hip extension – in brace, leg straight. Lie on stomach. Raise leg approximately

six inches off bed. Hold five seconds, relax. Repeat 10 times.

3. Range of Motion:

Begin passive range of motion using your unoperated leg to assist your operated leg.

Sit on edge of bed or chair. Unlock the brace so that your knee can move freely.

Using unoperated leg to support your operated leg, lower the operated leg until the

knee bends to 90 degrees. Use unoperated leg to straighten operated knee. Repeat

10 times, four times a day. Depending on the type of surgery you undergo, you might

not be able to start these motion exercises immediately after surgery.

4. Extension:

Place a pillow or folded towel under your heel (with nothing under the knee for

comfort). Push the knee straight, 3 times a day for 20 minutes.