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Anterior, Posterior and Medial Knee Ligaments

Anterior, Posterior and Medial Knee Ligaments

ACLs and PCLs- Injuries for All Four Seasons

Injury to the knee ligaments, such as the ACL and PCL, are always in season – especially if you’re an athlete that loves to ski, snowboard, play hockey, football, basketball, soccer, volleyball, and baseball. In the US, there are an estimated 200,000 ACL-related injuries per year with 100,000 ACL reconstructions.

How many ligaments does each knee have?

There are four ligaments per knee:

  • ACL (anterior cruciate ligament) Supports the femur
  • PCL (posterior cruciate ligament) Protects and supports the tibia
  • MCL (medial collateral ligament) Controls side to side motion of the femur
  • LCL (lateral collateral ligament) Prevents side to side motion of the femur

What is an ACL tear?

ACL stands for anterior cruciate ligament. It is an essential supportive ligament attached to the front of the knee joint and supports the connection of the knee to the femur bone. The injury is usually caused by a high-speed or a very forceful turn or coming to a sudden stop, which causes the ligament to rip. The symptoms are a loud popping sound or a feeling of popping in the knee, severe pain, and usually a disabled, unstable leg that will begin to swell and have reduced range of motion.

What is a PCL tear?

PCL stands for posterior cruciate ligament. The PCL is located at the back of the knee and serves to protect and support the tibia’s connection to the knee. A PCL injury is less common than an ACL injury. Among football players, it is usually caused by an awkward tackle where the knee is bent at an angle. It is not unusual to suffer a PCL ‘dashboard injury’ after an auto accident. The driver and passenger may experience enough force to shove the shin bone below the knee and cause the ligament at the rear of the knee to tear.

How does Dr. Greenberg diagnose injured knee ligaments?

Dr. Greenberg and his team will review your medical history and perform a Comprehensive Kinetic Diagnosis. They will examine the damaged knee plus everything connected to it from the lower back to the pelvis down to the ankles and feet. In the knee area, an ACL, PCL or MCL injury can also cause system-wide joint injury including cartilage, bursae, nerves and leg muscles. Only by looking at the big picture and assessing the kinetic dysfunction can a sound diagnosis and treatment program be established.

Is there a non-surgical alternative for ACL PCL and MCL tears?

Sometimes a ligament injury is not caused by a physical injury to the knee but is related to another physical issue such as a collapsed arch in a foot, a slightly twisted ankle or a leg length discrepancy. All it takes to damage the patella, stress a ligament or tear a medial meniscus is a change in your posture that skews your body to one side. With time, your knee can become destabilized and your pelvis may begin to tilt. A friend may comment that you seem to be limping, which comes as a complete surprise to you. Your body had automatically started to compensate for the changed kinetics.

To bring your body back into equilibrium, Dr. Greenberg brings your biomechanics to a balanced state, repairs ligaments and restabilizes your knee.

What is Kinetic Regeneration Therapy?

Sometimes the knee joint is so injured it needs to be regenerated. Dr. Greenberg developed Kinetic Regeneration Therapy (KRT) that includes Prolotherapy, Platelet-Rich Plasma and Stem Cell Treatments. The treatments activate the body’s natural regenerative system which contains components like stem cells, pericytes, fibroblasts, endothelial cells and macrophages which work together to regenerate the knee joint.

Before any treatment, Dr. Greenberg and his team will review the optimal treatment plan designed to help you improve knee functionality. You may require several treatments over a few weeks, and recovery may take six to eight weeks.

Why is an MCL injury considered The Great Masquerader?

The medial collateral ligament (MCL) is located on the inner side of the knee and is important for stabilizing the knee from outward turning forces. An MCL injury is often referred pain that seems to be located at the center of the knee. It can confuse a diagnostician, plus it may not appear on an MRI. Compounding things, an MCL injury often occurs with arthritis of the knee and meniscus tears so it can be difficult to pinpoint.

To correctly diagnose a torn MCL, Dr. Greenberg carefully examines your posture and gait. He will examine your knee, palpate it and test its strength to physically understand the state of all the components- tendons, ligaments, nerves and bones. Once an MCL tear is diagnosed correctly, Dr. Greenberg will try to correct your biomechanics, and treat the injured knee using Kinetic Regeneration Therapy.

If you or a loved one is looking for a new strategy to treat chronic aches and pains, fill out the form on this page to schedule an appointment or call Dr. Greenberg’s office today at (833) 440-4325.


In order to mitigate the spread of COVID-19 in our community, any patient that enters the building will be screened for the virus by having their temperature taken and filling out a questionnaire from Main Line Health. Once inside the office, patients will be asked to wash their hands immediately and may receive another temperature check. All patients will be able to maintain a safe social distance from others, as only one patient is seen per hour. The Greenberg Regenerative staff wears their masks at all times, and also ensures that all safety protocols and guidelines per Main Line Health and the CDC are being followed. Additionally, Dr. Greenberg is fully vaccinated, which further reduces possible COVID-19 transmission. At the end of the appointment, patients have the option to take a Greenberg Regenerative Medicine hand sanitizer to allow them to remain safe and healthy.