Posterior Cruciate Ligament Reconstruction
The Posterior cruciate ligament (PCL), one of four major ligaments of the knee is situated at the back of the knee. It connects the thigh bone (femur) to the shinbone (tibia). Injuries to the PCL are not common and can often be subtle and more difficult to evaluate than other knee ligament injuries.
The knee joint is made up of the femur, tibia, and the kneecap or patella. Bones are connected to other bones by ligaments. They are strong rope-like structures that help maintain stability of the knee joint. There are four main ligaments of the knee:
- Cruciate ligaments- the Anterior Cruciate ligament and the Posterior Cruciate ligaments are located inside the knee joint. They cross each other forming an X. Together the help to control the back and forth or anterior and posterior movements of the knee.
- Collateral ligaments- the Medial and Lateral collateral ligaments are located on the inside and outside of the knee respectively and help to control the side to side movements of the knee.
The PCL actually has two bundles of fibers that come together to form one structure. The main function of the PCL is to prevent the tibia from moving too far backwards (posteriorly), but part of the PCL also helps maintain stability in rotation of the knee when it is bent. The PCL is stronger than the ACL and is less commonly injured.
Injury to the PCL can happen in many ways although it generally requires a significant amount of force. Common mechanisms of injury to the PCL include:
- Direct injury to the knee- for example the dashboard hitting the bent knee during a car accident
- A direct and forceful fall onto a bent knee
- Significant twisting or hyperextension can also lead to PCL injuries
Symptoms and Diagnosis
Patients with PCL injuries usually experience knee pain and swelling immediately after the injury. There may also be instability in the knee joint, knee stiffness that causes limping, and difficulty in walking.
Diagnosis of a PCL tear is made on the basis of your symptoms, medical history, and by performing a physical examination of the knee. During the exam Dr. Faucett may check to see if the injured knee sags backwards when bent. X-rays are useful to rule out avulsion fractures where the PCL tears off a piece of bone along with it. An MRI scan is done to help view the images of soft tissues better and determine if there is sprain or tear of the PCL.
Injured ligaments are considered sprains and are graded based on severity:
- Grade 1: The ligament is mildly damaged in a Grade 1 Sprain. It has been slightly stretched, but is still able to help keep the knee joint stable.
- Grade 2: A Grade 2 Sprain stretches the ligament to the point where it becomes loose. This is often referred to as a partial tear of the ligament.
- Grade 3: This type of sprain is most commonly referred to as a complete tear of the ligament. The ligament has been split into two pieces, and the knee joint is unstable.
If you have injured your PCL, you may be able to heal without surgery. Nonsurgical options include:
- RICE- rest, ice, compression, and elevation (RICE protocol) to help decrease pain and swelling
- Immobilization- a knee brace may be recommended to immobilize and help stabilize your knee. Crutches may be recommended to protect your knee and avoid bearing weight on your leg.
- Physical therapy- to help improve range of motion and function
Generally, surgery is considered in patients with dislocated knee and several torn ligaments including the PCL. The procedure is generally done arthroscopically. Small incisions (portals) are made for the arthroscope (camera) and small surgical instruments.
Surgery involves reconstructing the torn ligament using a tissue graft which is taken from another part of your body, or a cadaver (another human donor). Following PCL reconstruction, you will need to wear a knee brace to protect the repair, and use crutches to avoid putting weight on the leg for several weeks. A rehabilitation program will be started that helps you resume a wider range of activities.
Usually, a complete recovery may take about 6 to 12 months.