Knee > ACL Tear > Treatments

    Reconstruction: Bone-Patellar Tendon-Bone Autograft or Allograft

Preparing for Surgery

If you and your doctor have decided on a patellar tendon reconstruction of your torn ACL (anterior cruciate ligament), the decisions you make and the actions you take before your surgery can be every bit as important as the procedure itself in ensuring a healthy recovery.

   Make sure you have received any equipment you will need when you get home from the hospital. This may include a knee brace, crutches, ice packs or coolers, or a continuous passive motion (CPM) machine. You should receive prescriptions for any of these from your doctor when your surgery is scheduled.

   Understand the potential risks and benefits of ACL reconstruction surgery, and ask your surgeon any questions that will help you better understand the procedure. It can also help to talk to someone else who has undergone the same surgery.

   Any physical problems, such as a fever or infection, should be reported to your surgeon, and you should notify your surgeon of any medication you are taking.

   If possible, practice walking with your crutches in case you need to use them after surgery.

   Getting a second opinion from a surgeon who is as qualified as the surgeon who gave the initial diagnosis is advisable in any case.

   To check if the orthopedist performing the surgery is board-certified or eligible, which can be determined by calling the American Board of Orthopaedic Surgery at 919-929-7103.

Day of surgery

At most medical centers, you will go to "patient admissions" to check in for your patellar tendon reconstruction of your torn ACL. If your surgery is going to be inpatient, there may be a separate department, so be sure to ask your doctor. After you have checked in to the hospital or clinic, you will go to a holding area where the final preparations are made. The paperwork is completed and your knee area may be shaved (this is not always necessary). You will wear a hospital gown and remove all of your jewelry. You will meet the anesthesiologist or nurse anesthetist (a nurse who has done graduate training to provide anesthesia under the supervision of an anesthesiologist). Then, you will walk or ride on a stretcher to the operating room. Most patients are not sedated until they go into the operating room. Here are some important steps to remember for the day of your surgery:

   You will probably be told not to eat or drink anything after midnight on the night before your surgery. This will reduce the risk of vomiting while you are under general anesthesia.

   You may be discharged the same day as the surgery, but you may stay overnight. Make arrangements for someone to drive you home when you are released.

   Wear a loose pair of pants or other clothing that will fit comfortably over your knee bandage when you leave the hospital.

   Take it easy. Keeping a good frame of mind can help ease any nerves or anxiety about undergoing surgery. Distractions such as reading, watching television, chatting with visitors, or talking on the telephone can also help.

Surgery Procedure [top]

The ACL is rebuilt using a graft from the patellar tendon and typically takes two to two-and-a-half hours. An autograft is a graft taken from the patient. An allograft is taken from a cadaver. Consult your physician about the advantages and disadvantages to each type of graft.

   General anesthesia is typically used for surgery, though in some cases a spinal or epidural anesthetic is used. The anesthesiologist will administer the anesthesia to put you to sleep once you are in the operating room.

   The surgeon makes an incision between two and three inches long and a graft, called an autograft, is taken from the middle portion of the patellar tendon, which is the ligament that connects the kneecap (patella) to the lower leg bone (tibia).

   If an allograft is used, there will be no need to cut and remove part of the patellar tendon.

   The surgeon uses an arthroscope to see inside the knee and small instruments to rebuild the ACL. The graft, which will become the new ACL, is attached to the upper leg bone (femur) and inserted to the lower leg bone through holes that are drilled.

   Metal screws are put in place to hold the tendon in place until it becomes permanently attached to the bone. The screws usually are not removed unless tenderness develops later on. Incisions are sewn up and the patient is taken to the recovery room.

Recovery Room  

Following ACL reconstruction surgery, you usually stay in the recovery room for at least two hours while the anesthetic wears off. You will be given adequate pain medicine, either orally or through an IV (intravenous) line. At the time of your discharge, you will be given instructions for what to do over the next couple of days. In addition, you will be given an appointment to return to see your physician and a prescription for pain medicine. Your knee will be bandaged and may have ice on it. There will likely be pain, and you can expect to be given pain medication as needed. Be sure to ask for medication as soon as you feel pain coming on, because pain medication works best on pain that is building rather than on pain that is already present. The nurses will not give you more than your doctor has prescribed and what is considered to be safe. You should try to move your feet while you are in the recovery room to improve circulation. Your temperature, blood pressure, and heartbeat will be monitored by a nurse, who, with the assistance of the doctor, will determine when you are ready to leave the hospital or, if necessary, be admitted for an overnight stay. It is likely that you will be able to bear some weight on your leg, but your surgeon may suggest that you use crutches or a cane for between two days and three weeks. Within two weeks, the majority of patients should be able to walk carefully without crutches. As soon as you are fully awakened, you are usually allowed to go home. You will probably be unable to drive a car, so be sure to have arranged a ride home.

Post-op in Hospital  

After ACL reconstruction surgery, some patients remain in the hospital for as long as 24 hours. As soon as possible after surgery is completed, you will begin doing continuous passive motion exercises while in bed. Your leg will be flexed and extended to keep the knee joint from becoming stiff. This may be done using a continuous passive motion (CPM) machine. The CPM is attached to your bed and then your leg is placed in it. When turned on, it takes your leg through a continuous range of motion. There will likely be pain, and you can expect to be given pain medication as needed. Be sure to ask for medication as soon as you feel pain coming on, because pain medication works best on pain that is building rather than on pain that is already present. The nurses will not give you more than your doctor has prescribed and what is considered to be safe. Ice also helps control pain and swelling.

Home Recovery [top]

Your rehabilitation program begins the moment you wake up in the recovery room and continues at home, to restore strength and range of motion to your knee. Here is what you can expect and how you can cope during the first days after surgery:

   You will likely feel pain or discomfort for the first few days. Take pain medications as your doctor advises. These could be over-the-counter painkillers, such as ibuprofen or acetaminophen, or stronger, prescription narcotic drugs.

   As much as possible, keep your knee elevated above heart level to reduce swelling and pain. Icing your knee for 20 or 30 minutes two or three times a day during the first two days after surgery also will reduce pain.

   Ask your doctor about when it will be safe for you to shower.

   The dressing on your knee is usually removed a day after surgery, during the first follow-up visit.

   Within a week after surgery, most patients are able to lift their leg without assistance while lying on their back. By the end of the second or third week, they normally are able to walk without crutches.

   As soon as possible after surgery, you should begin doing exercises using a continuous passive motion (CPM) machine while in bed. Your doctor can arrange to get you a CPM machine, which helps flex and extend the leg and prevents the joint from becoming stiff due to inactivity.

   Some people may experience night sweats and a fever of up to 101 degrees during the first two or three days after surgery. This is usually nothing to worry about. Your physician may suggest acetaminophen to bring the fever down.

Rehabilitation [top]

Your physician may prescribe visits to a physical therapist to begin supervised strengthening exercises as soon as possible after your ACL reconstruction. Recovery from a torn ACL takes an average of between four and six months with 45- to 60-minute exercise sessions three days a week. Though everyone's rehab program is slightly different, physical therapy for a torn ACL follows a general pattern. The first three weeks are usually spent restoring a full range of motion to your knee and recovering to the point of being able to walk without crutches. Movement may initially be painful, but it is important to not allow your knee to stiffen. Rehab progresses to resistive exercises to strengthen muscles around the knee. During this time, you should be able to resume functional activities like stair climbing, single leg support, swimming, and driving. After about three months, the emphasis will change from strengthening to functional training, as you begin exercises - specifically geared for your activities and lifestyle - to regain balance and control over your body. These may include more vigorous warmups on a stationary bike, elliptical trainer, or treadmill. You should be able to return to normal activities after about four months. Physicians usually suggest that you continue strength training even after your knee has been rehabilitated. Your doctor or therapist will likely check your knee for strength, endurance, and stability. The result of this evaluation will determine when you can return to sports or other activities.


Strengthening the hamstrings and quadriceps muscles may help prevent further knee injury. The more aggressive and dedicated you are during rehab, the better chance you have of a stable, pain-free knee. After up to six months of rehab, your knee may feel strong but your ACL may not stabilize your knee as well as it did before the injury. Many of the exercises and activities that are popular for fitness put stress on your knees. To prevent further knee injuries it is important to learn knee-sparing exercise techniques by dividing your activities into three components:

   Daily living - the average person takes between 12,000 and 15,000 steps a day, exerting a force between two and five times your body weight on your knees. After a knee injury, take it easy on your knees during the day whenever possible to save them for activities and exercise. Avoid stairs when there is an elevator, take the shortest path when walking, and consider wearing athletic shoes designed to absorb shock.

   Muscle strengthening/conditioning - activities themselves are not a substitute for conditioning. It is essential to adhere to the muscle strengthening program you learned in rehab throughout the remainder of your life. The best strengthening programs are low-impact and non-weight-bearing, like stationary bikes and certain weightlifting programs, so that the knees do not have to absorb shock.

   Recreation - your sport or activity of choice helps maintain mental and physical well-being, but it is not a conditioning program. Sports that require twisting and quick direction changes put great strain on your knee.

PAIN [top]

A small amount of pain is normal during physical activity, but if you feel so much pain in your knee to warrant taking a painkiller before an activity, you should consider cutting back or stopping. Do not play through the pain after an ACL injury - it may be a sign that your activity is putting too much stress on your knee.


No evidence has shown that braces prevent injuries, meaning they are not a substitute for increasing your muscle strength. Always consult your physician before buying or using a knee brace.

Physical Therapy
Reconstruction: Bone-Patellar Tendon-Bone Autograft or Allograft
   Preparing for Surgery
   Day of Surgery
   Surgery Procedure
   Recovery Room
   Post-op in Hospital
   Home Recovery
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