CPT Code: 27409
The posterior cruciate ligament (or PCL) is one of the four major ligaments of the knee. It connects the posterior intercondylar area of the tibia to the medial condyle of the femur. This configuration allows the PCL to resist forces pushing the tibia posteriorly relative to the femur.
In the quadruped stifle (analogous to the human knee), based on its anatomical position, it is referred to as the caudal cruciate ligament.
The PCL is an intracapsular ligament along with the anterior cruciate ligament (ACL) because it lies deep within the knee joint. They are both isolated from the fluid-filled synovial cavity, with the synovial membrane wrapped around them. The PCL gets its name by attaching to the posterior portion of the tibia.
Epidemiology Injuries to the Posterior Cruciate Ligament
Percentage of Posterior cruciate ligaments to other knee injuries
According to the posterior cruciate ligament injuries only account for 1.5 percent of all knee injuries. If it is a single injury to the posterior cruciate ligament that requires surgery only accounted for 1.1 percent compared to all other cruciate surgeries but when there was multiple injuries to the knee the posterior cruciate ligament accounted for 1.2 percent of injuries.
Recommendation for surgery to the posterior cruciate ligament
A grade III PLC injury with more than 10mm posterior translation when the posterior drawer examination is performed may be treated surgically. Patients that do not improve stability during physical therapy or develop an increase in pain will be recommended for surgery.
The Types of Mechanisms that Lead to PCL Injury
In this position, the PCL functions to prevent movement of the tibia in the posterior direction and to prevent the tilting or shifting of the patella. However, the respective laxity of the two sections makes the PCL susceptible to injury during hyperflexion, hyperextension, and in a mechanism known as a dashboard injury. Because ligaments are viscoelastic they can handle higher amounts of stress only when the load is increased slowly. When hyperflexion and hyperextension occur suddenly in combination with this viscoelastic behavior, the PCL deforms or tears. In the third and most common mechanism, the dashboard injury mechanism, the knee experiences impact in a posterior direction during knee flexion toward the space above the tibia. These mechanisms occur in excessive external tibial rotation and during falls that induce a combination of extension and adduction of the tibia, which is referred to as varus-extension stress, or that occur while the knee is flexed.
It is possible for the PCL to heal on its own. Surgery is usually required in complete tears of the ligament. Surgery usually takes place after a few weeks, in order to allow swelling to decrease and regular motion to return to the knee. A procedure called ligament reconstruction is used to replace the torn PCL with a new ligament, which is usually a graft taken from the hamstring or Achilles tendon from a host cadaver. An arthroscope allows a complete evaluation of the entire knee joint, including the knee cap (patella), the cartilage surfaces, the meniscus, the ligaments (ACL & PCL), and the joint lining. Then, the new ligament is attached to the bone of the thigh and lower leg with screws to hold it in place.