What is a Torn PCL
The posterior cruciate ligament, or PCL, is by far the largest ligament in the knee. It sits in the middle of the knee and helps to position the knee in a normal position. Because it is so big, it very rarely is torn on its own and usually is torn in a combination with other knee ligament injuries.
When one does tear their PCL, it is usually due to a blow to the front of the knee, such as can occur with a dashboard injury in a motor vehicle accident or when one falls on their flexed knee when skiing or skating. PCL tears can also occur in multiple other contact or noncontact mechanisms when there are other ligament injuries involved.
Standard For Treating PCL Tear
In the recent past, it was often common not to treat a complete PCL tear with surgery because the surgical results were dismal. Often, surgeons would perform PCL surgeries early in their career and found out that their outcomes were not that good, so they tended to abandon doing PCL reconstructions going forward.
More recently, we have performed an extensive amount of research at the Steadman Philippon Research Institute which has greatly advanced the treatment of PCL tears. Our comprehensive research program of studying the anatomy, redefining the biomechanics, and inventing new surgical techniques, combined with well thought out rehabilitation programs and dynamic bracing, has revolutionized the treatment of PCL tears. Our recent publications have noted that the outcomes of PCL surgeries are now equivalent to those of ACL surgeries in that when one does tear their PCL, they should have surgery to restore their knee stability and prevent the development of arthritis.
Anatomy of the PCL
As noted above, the PCL sits in the middle of the knee. It has a unique attachment on the thigh bone in that it attaches both on the roof at the center of the knee, called the intercondylar notch, as well as on the inside wall of the intracondylar notch. This gives it a very broad attachment surface. We have found that in order to reproduce this broad attachment surface, a double-bundle PCL reconstruction is necessary. Our robotic studies, similar to the robots that are used in the car industry, have demonstrated that double-bundle PCL reconstructions are far superior to single-bundle PCL reconstructions. In addition to its attachment on the femur, we have also defined its important attachment site on the shin bone (tibia). Probably the most common problem that we see in failed PCL reconstructions is that the reconstruction tunnel was not put in the correct position on the tibia and it often disrupts the meniscus root attachment. Unfortunately, since these surgeries are often performed in young patients, this leads to the development of arthritis. Thus, knowledge of the correct attachment site, and using intraoperative x-rays to confirm that one is putting the tunnel in the correct position, is mandatory.
How to Treat a PCL Injury
In addition to our studies which have defined that a double-bundle PCL reconstruction is the Gold Standard of treatment for PCL tears, we have also developed a surgical reconstruction technique which makes it technically easy. While our colleagues tell us that it is not uncommon for some PCL surgeries to take up to 6 hours, we have simplified the technique to the point where we can perform a double bundle PCL reconstruction in 25-30 minutes in a safe, efficient, and correct manner. Other surgeons and advanced sports medicine centers nationally and internationally have validated this.
PCL surgeries are unique in that the effects of gravity can greatly affect them. Thus, we have adapted a specific rehabilitation program for this. While in the past it was common to place a knee out straight in a brace for several weeks after a PCL reconstruction, due to the fear that the PCL graft would stretch out, we have validated that starting early motion when the patient is on their stomach, to negate the effects of gravity, is effective and does not cause the PCL grafts to stretch out. This is important because many centers have noted that up to 30% of patients often have to go back to surgery for stiffness because of this need to immobilize them. Thus, starting rehabilitation with our program of early motion on postoperative day 1 has basically eliminated this risk of stiffness in almost all patients.
PCL Brace
Finally, it is accepted that PCL reconstructions require a brace after surgery. In the past, most braces had a backwards ACL brace adapted, where the straps were switched from the front side to back, which were found to be ineffective. We have worked with a company in Iceland, Ossur, to develop a dynamic PCL brace which pushes the knee forward as one flexes the knee. This brace has been found to be very effective in protecting a PCL injury or surgical graft and has revolutionized the bracing of PCL surgeries postoperatively.
Going forward, it is anticipated that more PCLs will be reconstructed to better restore a patient’s stability and to prevent the development of arthritis over time. We are proud of the advanced research that has been performed at the Steadman Philippon Research Institute on PCL surgeries because it had greatly advanced their treatment over the last decade. While in the past most patients were doomed to having an unstable knee and the development of arthritis after a PCL injury, we now know that we can return most athletes back to high levels of competition and, by stabilizing their knee, help to prevent or slow down the progression of arthritis.
