PCL Reconstruction
What is a PCL reconstruction?
A posterior cruciate ligament (PCL) tear or rupture can lead to symptoms of knee instability. If untreated, these episodes of instability can potentially result in secondary damage to the menisci in the knee and cause accelerated arthritis in the kneecap. In some situations, a PCL brace can be used to allow the torn PCL to heal. If there is ongoing instability, a PCL reconstruction is performed. This involves harvesting a graft or using an allograft (cadaveric tissue) to form the new PCL.
What is involved in PCL reconstruction surgery?
The steps involved in posterior cruciate ligament reconstruction surgery include:
1. Knee arthroscopy
Key-hole surgery is performed to confirm the PCL tear and identify secondary injury to the cartilage and meniscus. Any secondary injuries are treated during the same procedure.
2. Graft harvest
A donor graft is harvested, prepared, and used to replace the torn PCL. This is usually the hamstring tendons. On occasion, an allograft (cadaveric tissue) is a graft. The graft choice is discussed between you and Mr Pai during your consultation and depends upon your sporting and work demands.
3. Tunnel drilling
Bone tunnels are created within the femur and tibia in a location that simulates PCL origin and insertion. The tunnels are required to allow passage of the graft. Getting an accurate bone tunnel is important so that favourable forces can pass through the PCL graft. An improper tunnel position can cause early re-rupture of the graft and is a common technical cause of graft failure or laxity.
4. Graft passage and fixation
The graft is passed through the bone tunnels and fixed into place with screws or over a loop of strong sutures threaded to a button.
A PCL reconstruction involves using a graft to replace the torn PCL which will restore knee stability. The graft, which lies within bone tunnels, is suspended using metallic buttons.
What is my follow-up schedule after the operation?
Approximately 3-4 weeks of leave from work is required for a desk-based job. You will require a post-operative brace for 6 weeks following surgery to protect the PCL graft. Mr Pai will refer you to have this fitted by an orthotist.
2 weeks
The wound dressings will be removed, and the wound will be reviewed to ensure it has healed. At this stage, the sutures will also be removed. The post-operative PCL brace should be worn for 6 weeks
8 weeks
The range of motion of the knee will be assessed. You are expected to be able to fully straighten the knee and bend it more than ninety degrees. The PCL brace will be discarded at this stage.
4 months
The range of motion and strength of the knee will be assessed. By this stage, you should have a near-normal range of motion. A small amount of residual swelling within the knee can be expected at this time point.
12 months
After the completion of a supervised post-operative course of rehabilitation, a referral is made for return to play testing to ensure you are safe to return to sport.
Frequently Asked Questions
What are the risks of having PCL surgery? +
General complications of PCL reconstruction surgery can include:
Infection
The risk is less than 1 in 400 of developing an infection. This can occur despite using a sterile surgical technique, giving pre-operative intravenous antibiotics, and soaking the graft tissue in antibiotics.
If the infection involves only the wound (superficial), it may just need treatment with a course of antibiotics.
If a deep knee joint infection occurs, it may require more surgery to wash out the knee as well as intravenous antibiotics. If the infection fails to resolve after this, the graft tissue may require removal.
Deep vein thrombosis and pulmonary embolism
Clots can occur in the deep veins of the leg that may dislodge and occlude the arteries in the lungs. DVT presents as leg pain and swelling after your operation. The diagnosis is confirmed with an ultrasound scan and, depending on the type of DVT, may require treatment with blood thinners.
Bleeding and haematoma formation
Small vessels at the surgical site continue to bleed post-operatively and cause swelling, bruising, and pain. Although most cases resolve with time, some will require a washout of the pooled blood beneath the surgical wounds.
Specific complications of PCL reconstruction surgery can include:
Saphenous nerve damage
This can occur when the hamstrings are harvested and will result in a numb patch on the inside of the leg. This usually improves with time but occasionally can be permanent. This does not affect the function of the ACL graft.
Difficulty kneeling
Patella tendon harvest is performed with an incision directly over the tendon at the front of the knee. As a result of the incision and the location of the graft, kneeling on the operated knee is sometimes poorly tolerated.
Graft re-rupture
Despite adequate rehabilitation, an PCL graft may fail. The risk is highest in the first year following PCL reconstruction, but is still higher than baseline between 1-2 years post-operatively. The risk is higher in younger patients. If this occurs, Mr Pai will talk to you about the option of revision surgery.
Stiffness
The knee can become stiff after surgery due to the formation of scar tissue. This stiffness usually resolves with physiotherapy but can sometimes persist. If the knee is not bending or straightening adequately 6-8 weeks post-operatively, a manipulation procedure may be required. This involves putting the patient to sleep and pushing on the knee in order to break the scar tissue.
Long-term osteoarthritis
Despite having an PCL reconstruction, the risk of developing kneecap osteoarthritis in the long term is higher than for the general population.
Compartment syndrome Fluid is passed through the knee joint to allow adequate visualisation during surgery. Sometimes this fluid can leak out into the calf muscle and increase the pressure in the muscle compartment. If the pressure is high, it can affect the blood supply of the calf and foot muscles. This can cause muscle death and permanent weakness if untreated. Compartment syndrome is treated with emergency surgery to release the pressure in the affected compartments. This is rare.
Damage to the common peroneal nerve Nerve injury may cause weakness in the muscles controlling the foot and ankle. This may be temporary or permanent and further surgery may be necessary. This is rare.
Damage to the popliteal artery If the popliteal artery behind the knee is damaged, surgery on the blood vessel will be needed, and sometimes leg amputation. This is rare.
Why do PCL tears happen? +
PCL tears occur because the knee is placed in a disadvantaged position and is unable to withstand the force being put through it. They either occur from a direct blow to the front of the knee when it is bent or from a hyperextension injury. To get an PCL tear, the knee has to partially dislocate. PCL injuries are far less common than ACL injuries.
Can I reinjure my reconstructed PCL? +
Although the tissue used to reconstruct your PCL typically biomechanically stronger than your native PCL, there is still a risk of reinjury to your reconstructed PCL. It is important to follow the post-operative instructions provided by Mr Pai and your physiotherapist to minimise that risk. A post-operative PCL brace will be prescribed for six weeks to protect the reconstruction. The risk is highest in the 12 months following your reconstruction, but is also slightly higher in the 12-24 month period. Prior to returning to sport, it is important to ensure that your muscle bulk is symmetrical to the uninjured side and that you have good control of your knee with the ability to perform single leg squats, hops, and other plyometric exercises. We will refer you to a physiotherapist for return to play testing within a suitable timeframe post-operatively.
Do I need an PCL reconstruction for my PCL tear? +
This depends on your level of activity, expectations and associated injuries. Typically, most isolated PCL injuries are managed without surgery. A PCL brace maybe prescribed to cause scarring of the PCL and restore some stability within the knee. If there is ongoing instability, a PCL reconstruction can be considered.
Sometimes, PCL injuries occur with other ligament injuries. When multiple ligaments are injured, it is important to restore knee stability early and PCL surgery may be recommended.
Am I too old to have an PCL reconstruction? +
There is no fixed age limit when you can have an PCL reconstruction. The decision to proceed with surgery is multifactorial and will depend on the presenting symptoms, the duration of time you have had an PCL tear for and the presence of cartilage damage or arthritis within the knee. If you are uncertain about whether an PCL reconstruction is in your best interests, Mr Pai would be happy to provide a balanced opinion about the management of your knee.
I have a torn meniscus as well as an PCL injury, will you repair the meniscus at the same time? +
Preserving and repairing the meniscus is always preferable to removing it. The meniscus acts like a cushion to support your cartilage. Having a torn meniscus is a common associated injury when you have an PCL tear. Any meniscal tears will be treated at the same time as your PCL reconstruction. If a meniscal repair is performed, it will slow your rehabilitation for the first few weeks as the repair needs to be protected. However, thereafter you will resume your PCL rehabilitation as normal. The advantage of performing the meniscal repair at the same time as the PCL reconstruction is that the repair is more likely to be succesful. The bleeding into the knee that occurs after an PCL reconstruction is rich in growth factors which promotes tissue healing.
Read more about meniscal repair.
When can I walk after an PCL reconstruction? +
You will be walking and bearing weight with crutches on the day of surgery after a PCL reconstruction. Crutches are used to make walking and bearing weight comfortable. Most patients require them for 3-4 weeks after surgery. A post-operative brace is required for six weeks following surgery.
When can I drive after an PCL reconstruction +
You will not be able to drive for 6 weeks following an PCL reconstruction. You must be off strong painkillers, be walking without crutches and have a relatively painfree range of motion in the affected knee before your commence driving.
When can I swim after an PCL reconstruction? +
The wound should be kept dry for two weeks following the operation. Once the wound healing is reviewed at your 2-week post-operative consultation you will be able to shower with no wound dressings on. Participating in pool based rehabilitation or swimming is not recommended for 4 weeks after your operation as it may increase the risk of infection.
When can I return to playing sport after PCL surgery? +
There are various factors that determine when someone can return to playing competitive sport after having an PCL reconstruction. It is crucial to make sure that the PCL graft has healed adequately and that the athletes muscle strength and control has returned to near-normal levels before returning to sport. This usually occurs at a minimum of 12 months after the operation.