The posterior cruciate ligament (or PCL ) is one of the four major knee ligaments. It connects the posterior intercondylous region of the tibia to the medial condyle of the femur. This configuration allows PCL to resist the force of pushing the tibia posteriorly relative to the femur.
PCL is the intracapsular ligament along with the anterior cruciate ligament (ACL) because it is located deep inside the knee joint. They are both isolated from a fluid-filled synovial cavity, with a synovial membrane wrapped around them. PCL gets its name by attaching to the posterior part of the tibia.
Video Posterior cruciate ligament
Structure
The PCL is located inside the knee joint where it stabilizes the articulating bone, especially the femur and tibia, during movement. It comes from the lateral edge of the medial femoral condyle and the intercondyle notch roof then stretches, at the posterior and lateral angles, toward the posterior tibia just beneath the articular surface.
Maps Posterior cruciate ligament
Function
Although each PCL is an integrated unit, they are described as separate anterolateral and posteromedial sections based on where the site and attachment functions of each section. During knee joint movement, PCL rotates such that the anterolateral part extends in knee flexion but not in knee extension and posteromedial bundle extends in extension rather than flexion.
The PCL function is to prevent the femur from shifting from the anterior edge of the tibia and to prevent the tibia shifting posteriorly to the femur. The posterior cruciate ligament lies inside the knee. Ligaments are strong tissue bands that connect bones. Similar to the anterior cruciate ligament, PCL connects the femur to the tibia.
Clinical interests
The common cause of injury is a direct blow to the knee flexed, such as knees hitting the dashboard in a car crash or falling hard on the knee, both instances shifting the posterior tibia to the femur.
Additional tests of posterior cruciate ligament injuries are posterior sag tests , where, unlike the drawer tests, no active force is applied. Instead, the person is stretched out with a leg held by another so that the hip is folded to 90 degrees and 90 degrees knees. The main parameter in this test is the step-off , which is the shortest distance from the femur to the hypothetical line that pertains to the tibia's surface of the tibial and upward tuberosities. Typically, the step-off is approximately 1 cm, but decreases (Level I) or even absent (Level II) or upside (Level III) in injury to the posterior cruciate ligament. The posterior drawer test is one of the tests used by physicians and physiotherapists to detect injuries to PCL. Patients suspected of having a posterior ligament injury should always be evaluated for other frequent knee injuries in combination with PCL injuries. These include cartilage/meniscus injuries, bruises in the bones, ACL tears, fractures, posterolateral injuries and collateral ligament injuries.
There are four different classification classes in which doctors classify PCL injuries: Grade I, PCL has a tear. Grade II, a minimal PCL ligament tear and become loose. Grade III, a fully torn PCL and knee can now be categorized as unstable. Grade IV, ligaments damaged along with other ligaments placed on the knee (ie ACL). With this level of PCL injury, there are different treatments available for such injuries.
Mechanism
In this position, the PCL function to prevent tibia movements towards the posterior and to prevent oblique or patellar shifts. However, the disadvantages of each of the two parts make PCL vulnerable to injury during hyperflection, hyperextension, and in a mechanism known as a dash injury. Because the ligaments are viscoelastic) they can handle a higher amount of stress only when the load is raised slowly. When hyperflexion and hyperextension occur suddenly in combination with this viscoelastic behavior, PCL destroys shapes or rips. In the third and most common mechanism, the dashboard injury mechanism, the knee is impacted in the posterior direction during flexed knee against space above the tibia. This mechanism occurs in the excessive rotation of the external tibia and during falling causing a combination of extension and tibia adduction, called the varus-extension voltage, or which occurs when the knee is flexed.
Treatment
It is possible for PCL to heal by itself. Surgery is usually required in ligament tears. Surgery usually occurs after a few weeks, to allow for decreased swelling and regular movement to return to the knee. A procedure called ligament reconstruction is used to replace a torn PCL with a new ligament, which is usually a graft taken from a hamstring or Achilles tendon from the parent pouch. Arthroscope allows complete evaluation of all knee joints, including the knee (patella), cartilage surface, meniscus, ligaments (ACL & PCL), and joint lining. Then, the new ligaments attached to the femur and lower leg with a screw to hold it in place. Surgery to repair a controversial posterior cruciate ligament due to placement and technical difficulties.
It is possible for PCL to heal itself without surgery when it is a Grade I or Grade II injury. PCL injuries diagnosed in this category can reduce their recovery time by performing certain rehabilitation exercises. Fernandez and Pugh (2012) found that after a diagnosis of PCL grade II, a 8-week multimodal treatment consisting of chiropractic lumbopelvic manipulation, physiotherapy, and an exercise program that emphasized eccentric muscle contraction (lunges, 1-leg squats, and stem stabilization proved to be an effective way to recover from PCL injuries. For Class III and IV, operative surgery is recommended or usually required. Grafts are a method when handling PCL injuries that require surgical surgery.There are several different methods such as the tibial inlay or tunnel method.
Other animals
In the four-legged (analogous to the human knee), based on its anatomical position, this is referred to as caudal cruciate ligament .
Additional images
References
External links
- lljoints at The Anatomy Lesson by Wesley Norman (Georgetown University) ( antkneejointopenflexed )
- Dealing with Ligament Tearing at Knee
- http://www.orthspec.com/pdfs/PCL-injuries.pdf
Source of the article : Wikipedia
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