The posterior cruciate ligament, commonly known as the PCL, crosses inside of the knee joint with the anterior cruciate ligament, commonly known as the ACL, connecting the thigh bone to the leg. PCL tears are not as common as ACL tears. PCL tears can result from twisting movements, falls, or direct contact to the knee or shin bone. PCL tears can be treated with both surgical and nonsurgical methods.
Bones in the Knee
The knee is one of the more structurally complex areas of the body. The knee is composed of three bones:
- The Tibia, or shinbone
- The Femur, or thighbone, sits on top of the tibia, the larger leg bone.
- The Patella, or kneecap, glides in a groove on the end of the femur.
Muscles in the Thigh
Large muscle groupings in the thigh give the knee its strength and stability:
- The quadriceps muscles-group of muscles on the front of the thigh that straighten and rotate the leg.
- The hamstring muscles- located on the back of the thigh and bend or flex the knee.
Ligaments Surrounding the Knee
Ligaments are strong tissues that provide stability and allow the leg to move. They also enable flexibility while maintaining balance. Four ligaments connect our knee bones together:
- The medial collateral is located on the inside of the knee, and the lateral collateral is at the outer side of the knee. These two ligaments help the joint to resist side to side stress.
- The anterior cruciate ligament and the posterior cruciate ligament cross each other inside of the knee joint. These ligaments help to keep the joint aligned. They also counteract forward and backward forces and keep the bones in place. They also control rotation of the tibia.
Cartilage, Synovium, and Nerve Fibers
Two cartilage disks, Menisci, are located on the end of the tibia. This cartilage forms a smooth surface, allowing the bones to glide easily during motion. The menisci act as shock absorbers when we walk or run.
A smooth tissue capsule covers the bones in our knee, and a thin synovial membrane lines this capsule. The synovium secretes a liquid known as synovial fluid. The synovial fluid acts as a cushion and lubricant between the joints, which allows the knee to move painlessly. Proprioceptive nerve fibers are inside in the ligaments and joint capsules, sending signals throughout the body.
PCL Tear Causes
PCL tears happen when the shinbone is impacted by force just below the knee or also on the side of the knee while the leg is twisted. These injuries stem from bending the knee more than its normal range. PCL injuries can occur during contact sports, but are also commonplace for car crashes, because the toes are pointed.
PCL Tear Symptoms
Initial symptoms of a PCL tear can actually be vague, and some may not even know that they have an injury. However, the pain will worsen over time and the knee will begin to feel unstable. PCL tears can cause:
- Knee pain ranging from mild to moderate
- Rapid knee swelling
- Tenderness in the knee
- Pain while kneeling, squatting, running, slowing down or walking on an incline
- Problems walking in general
- Knee instability, or feeling that the knee “gives out”
PCL Tear Diagnosis
If you suspect you have torn your PCL, you should seek immediate medical attention. A doctor can evaluate your knee and will examine your knee and your leg alignment. You may be asked to perform simple movements to help the doctor determine muscle strength, joint motion, and stability.
The doctor will order X-Rays to identify any suspected fractures. Tears in the knee do not typically come alone.
Immediately after an injury, your knee will need to be treated with RICE: rest, ice, compression, and elevation. Resting the knee means staying off of it. If you must walk, use crutches. Applying ice packs to your knee can help reduce pain and swelling. Elevating and icing the knee will help to reduce swelling. A doctor may recommend an icing schedule as well as a knee brace.
Treatment for PCL tears varies around several factors, such as your activity level, severity of injury, and degree of knee instability.
The treatments may include physical therapy, surgery, or both. In order to be a candidate for a non-surgical treatment, the patient must have partial PCL tears without knee instability, complete tears without knee instability, live a sedentary lifestyle, or are children whose knees are still developing.
Physical therapy and rehabilitation can help restore knee’s function. The physical therapist will help strengthen the knee, with a special emphasis placed on exercising the quadriceps.
PCL Reconstructive Surgery
Surgical treatment is recommended for those with PCL tears along with other injuries. Patients who are active individuals, whether it be sports, job, or lifestyle, in general. It is also recommended for those with unstable knees and have multiple injuries, such as damage to the meniscus, articular cartilage, joint capsule, or ligaments.
In most cases, patients are advised to participate in physical therapy. Swelling can make the knee stiff, and immobility can cause the muscles and ligaments to actually shorten. A physical therapist will help to stretch the knee to regain full movement. However, if the collateral ligaments are involved, a brace may be needed prior to your surgery.
During PCL surgery, the damaged PCL is taken and replaced with a graft. There are a few options for acquiring grafts. Grafts can either be taken from another part of the body or from a donor cadaver. An orthopedic surgeon, like Dr. Berry will use an arthroscope to perform surgery on a PCL tear.
Many PCL reconstruction surgeries are outpatient procedures. The patient may either be anesthetized for surgery or receive a nerve block. The surgeon will make one or more small incisions, about a quarter to half inch in length, near the joint. The surgeon will fill the joint space with a sterile saline solution, to expand the area. The surgeon will then insert an arthroscope and will reposition it to see the joint from multiple angles.
After this, the surgeon may make more small incisions. The new graft is attached using surgical hardware. The surgeon will then test the new graft and the knee’s function. Again, the surgeon will examine the knee by performing similar muscle tests conducted during the clinical examination to ensure that the knee is stable and has a full range of motion.
Most patients may go home the same day after surgery and are sent home with pain medication to help the post-surgery pain.The doctor may advise ice or to keep the leg elevated and may also prescribe blood thinning medication and special support stockings. As with most procedures, RICE is advised: rest, ice, compression, and elevation.