Posterior Cruciate Ligament (PCL) reconstruction
Pre-Operation
Most PCL injuries in sport are a result of direct impact to the leg just below the level of the knee. For example falling from a height (a mark or line out perhaps). Less often it collapses during a propping-type deceleration / cutting manoeuvre at sport.
If it is an isolated injury, the injured person may attempt to return to play or even complete the game, as it can be less obvious than an ACL tear. Swelling tends to increase over the next few hours and days.
Patients may be aware of the instability on descending stairs or decelerating abruptly. If there are other injuries to the knee, the patient may have instability with any twisting or pivoting, an / or the knee may lock up.
Some PCL injuries are a result of a car accident when the knee is driven against the dashboard of the car.
When Dr. Porter examines the knee the injured knee, the diagnosis may be possible on clinical assessment. The tibia (leg) tends to “sit back” further than it should, relative to the uninjured knee. When the tibia is pushed backwards, the lack of an end point may be obvious.
There are other tests such as the “dial sign” and the “reverse pivot shift” which he will perform to determine if there is damage to other structures, often the lateral and posterolateral structures may be involved in the case of more traumatic injuries.
If PCL injuries present early and are diagnoses early, they may only require treatment in a brace of 6-8 weeks, followed by rehabilitation. If this is appropriate Dr. Porter will put you in PCL-specific brace.
Other times PCL reconstruction may be the treatment recommended, and this is more likely to be indicated when the ligament damage is more severe and the patient is keen to return to higher demand twisting / pivoting sports.
An MRI is often performed and this may assist with diagnosis or operative planning, but is less important the physical assessment.
Operation
The operation is performed in an operating theatre with the patient under a general anesthetic.
The first part of the operation involves an “arthroscopy” during which a small camera is placed into the knee, and used to confirm the diagnosis and the severity of the the injury, as well as to diagnose and treat any other injury within the knee. The latter may include cartilage injuries (chondral cartilage of meniscal cartilage). The arthroscopy is performed via two small 1cm incisions in the skin (called “portals”)
PCL injuries coming to surgery may be repairable, especially if the present early and are diagnosed early. This is more likely to be the case in younger patients. If this is possible then Dr. Porter will used strong suture material to repair the ligament back to bone. The advantage of a repair, rather than a reconstruction, is that the recovery is much quicker, and patients can be back to most activities within 3-4 month of the surgery, and the surgery is arthroscopic and therefore less painful.
If the PCL is not repairable, then a new one has to be made, and this is referred to as a reconstruction. There tissue used can be from the patient (autograft) and most commonly a hamstring tendon, or a donated tissue (allograft). Dr. Porter only used non-irradated allografts from younger donors. Artificial or non-biological grafts are not used by Dr. Porter as the artificial ligaments not only fail but can cause significant damage to the joint when they fail, caused by the artificial tissue debris within the knee joint (polyethylene synovitis).
If the graft is taken from the patient this is done so though a small incision at there top of the shin bone (tibia) and the tendon only is removed. The recovery is similar to that for a complete tear of one the hamstrings, but it does recover, albeit with a possible loss of 2-3% of hamstring strength.
This graft is then used to make the new PCL, which is position in the knee, where the old PCL used to run, and is fixed at both ends with screws within tunnels. The screws are usually made of a material referred to as “hydroxy-apatite”, which turns to bone over a period of up 2 years. This avoids the presence of metal screws within the knee, and it means that the tunnels fill with new bone as the graft becomes a living ligament.
At the end of the procedure the knee is placed in a “range of motion” brace and the patient is non-weight bearing for the first 10 days.
Intra-operative x-ray control is used to check the position of the tibial tunnel is correct and the neurovascular structures at the back of the knee are protected (above left). The graft is then secured in the correctly positioned bone tunnels (above right).
PCL reconstruction. Above left - the tibial tunnel being positioned and drilled under x-ray control. Above right - the graft positioned correctly within the knee and replacing the previous PCL.
Post-Operation
Most PCL reconstructions are perform as day surgery, or one night in hospital at the most.
Between surgery and the fist post-operative review the patient will perform some simple home exercises, and attend for physiotherapy.
There is a specific protocol that the patient follows which is supervised by the physiotherapist.
Dr. Porter will review you in his rooms around 10 days post surgery, at 6 weeks post surgery and at 6 months post surgery, as well as at any stage if there are any problems.
Clicking on the link below will take you to a printable copy of the post-operative guidelines.