Posterior cruciate ligament reconstruction

A posterior cruciate ligament injury occurs when the ligament is torn or ruptured. This can happen during strenuous sports activities or from a direct blow to the knee.

Once injured, the PCL tear may heal naturally, but often the ligament becomes longer than normal during the healing process. This can cause the knee to give way, but more usually causes chronic PCL pain and, in the long term, osteoarthritis or wear of the knee.

Minor or moderate lengthening of the PCL can be treated by physiotherapy or muscle strengthening. However, a severe injury of the PCL, as opposed to a posterior cruciate ligament sprain, will require reconstructive surgery.

A PCL reconstruction uses a graft to reconstruct the damaged ligament. The graft is often taken from part of your hamstring tendons behind the knee or from the ligaments at the front of the knee. Both of these are able to re-grow to a large extent.

Once fixed in the knee, the graft is able to form a new ligament. This process takes up to a year but you would normally be able to return to sports activity after six months.

The PCL ligament tear symptoms can vary, depending on the time when your injury occurred. For an ACL or PCL tear, knee ligament pain and rapid swelling are likely. In some cases, you may hear and/or feel a pop in your knee.

You will usually be able to identify whether a PCL has been torn based on the location of the pain and swelling. For most PCL injuries, you will feel a sharp or dull pain around the back of the knee. This can occur immediately or develop in the hours or days after the injury. Bleeding around the torn ligament may result in swelling.

During the first few weeks after the knee injury, your level of pain and swelling should start to reduce. However, your knee may become increasingly stiff and you will feel some weakness and instability in the knee joint ligaments.

Beyond this timeframe, your knee may continue to be unstable and you may have the sensation of your knee ‘giving way’ as well as recurring knee pain.

Your consultant will be able to diagnose what type of injury your knee has sustained, such as a partial PCL tear or an isolated PCL tear.

PCL reconstruction is usually performed through keyhole surgery (also called an athroscopy) under general anaesthetic. You would normally be admitted on the day of the operation and have an overnight stay in hospital.

You will not be able to eat for eight hours prior to surgery although you will be able to drink small amounts of water up to four hours before.

The operation takes about one hour. During the procedure, your surgeon will make small incisions in your knee to allow small specially designed instruments to be introduced. This instrument is called an arthroscope.

The torn ligaments are trimmed and the knee is prepared for the replacement graft. The top and bottom ends of the replacement ligament are fixed into place with special screws that are secured using holes drilled into your bones.

The incisions are closed with stitches or adhesive strips.

Recovery from the general anaesthetic is usually quick and you will be awake very soon after the operation although you may feel drowsy for an hour or two. Your leg will be placed in a knee brace or sometimes in a plaster cast.

After being shown how to walk with elbow crutches by a physical therapist, you will be allowed to go home. Your physiotherapists will give you a range of PCL tear exercises for your leg before you leave the hospital. If needed, outpatient physiotherapy may also be arranged for you.

Regular stretching of the knee, particularly from bent knee into extension, is encouraged along with other PCL tear exercises. Knee flexions will also help to reduce stiffness of the knee joint. 

You will be given a cold compress or 'Cryocuff' along with instructions on how to cool your knee, which is important to aid recovery. Then two weeks after your operation, you will see your consultant again to review your progress.

You may need to take four to six weeks off work and driving following the operation. Rehabilitation following a PCL reconstruction is extensive and you will require physiotherapy once a week for two to three months and less frequently up to nine months.

As with any surgery there are potential risks. Although PCL reconstruction is a common procedure and generally safe, there are some potential complications. These only affect less than 4% of patients.

• Infection can occur, although our theatres have ultra-clean air operating conditions keeping infection rates at 1-2%.
• Blood clots are possible but again are in the 1-4% category and have well-established treatments, including aspirin.
• A small patch of numb skin can be present on the outer part of the knee near the kneecap, this will improve over time.