Posterior Cruciate Ligament (PCL) Tears
The posterior cruciate ligament is situated at the back of the knee and connects the femur (thigh bone) to the tibia (shin bone). It is the largest and strongest ligament in the knee and the primary posterior stabilizer. It controls the backward motion of the tibia and internal rotation.
A tear of the PCL is a relatively common type of knee injury, although it is less common than tears of the Anterior Cruciate Ligament (ACL). PCL injuries rarely occur in isolation. Rather up to 95% of PCL tears occur in combination with other knee ligament and cartilage injuries. PCL injuries are usually caused by violent impact, sports accidents and traffic accidents.
Isolated Grade I or II can often be treated nonoperatively. However, when an acute grade III rupture occurs with other ligament or meniscus tears, surgery is indicated. PCL reconstruction within 3 weeks after PCL injury is more advantageous to the recovery of a patient’s knee joint function.
- Trauma: A direct blow to the front of the knee while the knee is bent can cause a PCL tear. This can occur in car accidents (often referred to as a “dashboard injury”), during sports when an athlete falls forward with a bent knee hitting the ground, or in any situation where there is forceful impact or hyperextension of the knee.
- Sports Injuries: Sudden stops or changes in direction, awkward landings, or direct contact, like in football or soccer, rugby or skiing are the sports with the highest incidence of PCL tears.
Common symptoms of a PCL tear include:
- Pain: Initially severe but might settle down fairly quickly compared to an ACL tear.
- Stiffness in the Knee: Limited range of motion and difficulty in bending or straightening the knee.
- Swelling: Immediate and sustained swelling in the knee.
- Instability: A feeling that the knee might give way under stress or load, often described as a feeling of looseness in the knee.
- Difficulty Walking or Weight-bearing: Patients may limp or have difficulty putting weight on the knee.
Diagnosis is generally made through a combination of patient history, physical examination, symptoms and imaging studies. During the physical examination, Dr. Masi Reynolds will perform specific tests designed to stress the PCL and evaluate the stability of the knee, he will also compare the injured knee with the uninjured knee. He will order standard and stress X-rays to view the bones and rule out fractures. An MRI will help him visualize the ligaments in the knee and confirm the diagnosis. It has a near 100% accuracy for the diagnosis of acute PCL tears.
The treatment can vary based on the severity of the injury, whether other structures in the knee are injured, and the patient’s activity level and goals. Options include:
- Partial isolated PCL tears can be treated nonoperatively with rest, icing, compression and elevation to reduce pain and swelling. This is because the PCL has inherent healing capacity. Physical therapy is necessary to restore function and strength to the knee. A brace may be needed to keep the tibia in the correct position and protect the ligament as it heals. Pain can be managed with NSAIDs, and short-term prescription pain medications.
- Complete isolated PCL tears and combined PCL injuries and when the patient is an athlete or very active, surgical reconstruction of the PCL may be recommended to restore joint stability and improve function. This generally involves replacing the torn ligament with a graft, which can be a tendon from another part of the patient’s body or from a donor.
Recovery time from a PCL tear varies. For non-surgical treatment, substantial healing may occur within several weeks to a few months. Surgical recovery is typically longer and will involve intensive physical therapy. The first six weeks the patient will wear a brace to keep weight off the knee to allow the graft to heal.
Rehabilitation is crucial to good outcomes beginning with range of motion exercises on day one post operative and progresses up to six months postoperatively with a gradual introduction to sport specific drills. Complete recovery with a return to full athletic activity may take 9 to 12 months or longer after surgery.