Posterior Cruciate Ligament Injury: Symptoms and Management
The posterior cruciate ligament is considered the "strength" of the knee; unlike its counterpart, the anterior cruciate ligament, it is thicker as it is a primary stabilizer of the knee. It is located at the back of the knee, connecting the tibia and the medial femoral condyle. It prevents the tibia from shifting backward, which is where its importance lies.
Its rupture is not as common as that of the ACL. Due to its position and thickness, it is not as easily injured, but it can happen. The main causes are falls onto a flexed knee with the foot pointing downward—the tibia hits the ground first and shifts backward, producing the tear. Also, blows to the knee when it is flexed or sudden changes in direction while running.
Symptoms:
The main symptoms are the pain and inflammation the patient feels; it happens right after the injury, and as minutes pass, the knee will begin to stiffen, causing limping or mobility limitations. The patient will also feel their knee is "giving way" under weight or while walking, due to the instability generated.
This injury can occur in different grades:
Grade 1 Sprain: The ligament stretches but does not break. It can still keep the joint stable.
Grade 2 Sprain: It is a partial tear. The ligament stretches and loosens.
Grade 3 Sprain: It is a complete tear of the ligament. At this point, it is totally divided in two, and the knee is unstable.
Management:
Depending on the patient, their lifestyle, and sports practice, the treatment to follow can be defined. If the knee still has minimum stability and the patient does not perform any type of high-performance or recreational sport, a more conservative approach is usually chosen, such as analgesics, anti-inflammatories, rest, ice, elevation, and physical therapy. If, on the contrary, there is a very marked instability or if they are a high-level athlete, the surgical option usually provides the best results. When this injury occurs, it is common for there to be others associated with the anterior cruciate ligament or other structures like the menisci; in those cases, surgery is also the best option.
During arthroscopy, the damaged ligament is removed and replaced with a tendon, either from the patient themselves or an allograft; it is done this way because joining the two ends does not guarantee they will heal, as they are cord-like ligaments, meaning they retract and cannot repair themselves.
