What is a posterior cruciate ligament injury?
A posterior cruciate ligament (PCL) injury occurs when the posterior cruciate ligament, ligament in the back of the knee that connects the thighbone (femur) to the shinbone (tibia), tears due to powerful force to the back of the knee.
PCL injuries are uncommon and hard to diagnose. Often, PCL injuries occur in combination with other knee injuries, which further complicates the diagnosis.
Causes of posterior cruciate ligament (PCL) injury
Posterior cruciate ligament injuries are most commonly caused by severe trauma to the knee joint.
Other causes of PCL injuries include:
- Direct force to the front of the knee while it is bent or flexed
- Hyperextension of the knee from activities like jumping in sports
- Car accidents when the bent knee hits the dashboard
Risk factors for posterior cruciate ligament (PCL) injury
- Being in a car collision
- Playing high-impact sports
Symptoms of a posterior cruciate ligament (PCL) injury
- Pain and instability in the knee joint
- Swelling and tenderness in the back of the knee
- Difficulty walking and making simple knee movements
- Stiffness in the knee joint
- Unstable knee that feels like it may collapse under the weight of the body
- Limp from the pain associated with the injury
Diagnosis of a posterior cruciate ligament (PCL) injury
A posterior cruciate ligament injury is diagnosed in a physical exam with your primary care or orthopedic physician.
During the physical exam, the doctor will fully examine the knee and look for the following signs of a PCL injury:
- Knee sagging backward when bent
- Knee that slides backward too far when bent more than 90 degrees
- Swelling and bruising
The physician may also order an x-ray or MRI to confirm a PCL diagnosis. The x-ray will be able to determine if the patient also sustained more serious knee injuries in addition to a PCL injury.
Treatment for posterior cruciate ligament (PCL) injury
Depending on the severity of the injury, the physician will prescribe nonsurgical or surgical treatments to treat your posterior cruciate ligament injury.
Nonsurgical treatment options for PCL injury:
- Anti-inflammatory medication can relieve pain or swelling
- Physical therapy and rehabilitation — your physician may prescribe physical therapy to help you improve knee stability, make the knee stronger and help improve knee function after a PCL injury.
- Brace or crutches — your physician may recommend using knee braces or crutches to facilitate healing during physical therapy.
- Platelet rich plasma (PRP) injection — a PRP injection is a newer orthopedic procedure where blood is taken from the patient, the blood is spun in a centrifuge and the growth factors that are isolated are injected into the affected area to stimulate healing.
Surgical treatments are recommended for more severe cases or if the injury is combined with other knee injuries. Most PCL injuries can be treated arthroscopically. In an arthroscopic procedure, the orthopedic surgeon cuts small incisions at the injury site, inserts a camera into the knee and then fixes the injury.
Recovery from posterior cruciate ligament (PCL) injury
Recovery from a PCL sprain or tear depends on the severity of the injury. Mild (Grade 1) sprains take ten days to two weeks to heal. Moderate (Grade 2) sprains take three to four weeks to fully recover.
Athletes should work closely with their physician to determine when to return to their sport. Most athletes can return to their sport within eight weeks as long as there are no other complications associated with the injury.