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A medial patellofemoral ligament, or MPFL, injury is damage to the ligament that stabilizes the knee. The medial patellofemoral ligament helps to keep the kneecap centered along the front of the knee. This helps it track well during knee movements such as bending and straightening the knee. MPFL injuries typically occur during a traumatic kneecap dislocation. This injury is most common among young, active females. Depending on the severity of an MPFL injury, treatment may involve surgery. Physical therapists design treatment programs for people with MPFL injuries to help restore knee strength and function. If surgery is required, physical therapy will follow to ensure a safe return to activity.

Physical therapists are movement experts. They improve quality of life through hands-on care, patient education, and prescribed movement. You can contact a physical therapist directly for an evaluation. To find a physical therapist in your area, visit Find a PT.

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What Is a Medial Patellofemoral Injury?

MPFL injuries often result from a traumatic kneecap dislocation. People who are naturally very flexible can develop MPFL laxity (looseness) that leads to injury. The MPFL is a broad structure located on the inside of the knee joint. It connects the kneecap (patella) to the thigh bone (femur). The primary purpose of the MPFL is to provide stability to the kneecap. It restrains any movement toward the outside of the knee. It also helps keep the kneecap in position, as the knee bends and straightens.

How Does It Feel?

Common signs and symptoms that may occur with an MPFL injury include:

  • Feeling the knee "give way" or "buckle" during activity.
  • Feeling like the kneecap is sliding out to the side during knee movement.
  • Swelling of the knee after activity.
  • Restricted joint movement (range of motion).
  • Pain when moving the knee.
  • Tenderness to touch along the knee joint.
  • Pain, stiffness, or "locking" after sitting with the knee bent or straight for a long time.

How Is It Diagnosed?

Your physical therapist will review your medical history. They will ask you how and when you injured your knee and to describe your symptoms. Your physical therapist will perform a complete physical exam of your knee. This will include assessing your knee range of motion, strength, and flexibility. They may gently move your knee into certain positions to pinpoint which part of your knee is injured.

If they suspect an MPFL injury, your physical therapist may assess the mobility of your kneecap. This will help to determine if it moves more to the outside compared to your uninjured knee. You also may be asked to briefly do or describe the activities that cause your pain.

Your physical therapist may refer you to your doctor to get diagnostic images. In some cases, X-rays or an MRI can help to further evaluate the structures of the knee joint. Depending on the results, you may need to see an orthopedic doctor to find out if you need surgery.

How Can a Physical Therapist Help?

Physical therapy (conservative treatment) is the standard of care for MFPL injuries. Physical therapists also provide treatment after any needed surgery. Your physical therapist will design a treatment program specific to your knee condition and goals. Your treatment may include:

Range-of-motion exercises. When there is an injury to a joint, our bodies tend to become guarded. This may limit the knee joint’s range of motion. Your physical therapist will compare the range of motion of your injured knee with the expected normal motion. They also will compare it with your other knee joint. They will prescribe exercises to help restore normal knee motion.

Muscle strengthening. Strengthening the muscles around the injured joint is an important part of recovery. The muscles on the front and back of the thigh (quadriceps and hamstrings) help manage the forces applied to the knee. Pain and swelling often cause these muscles to not function at their best. Strengthening the hip and core muscles can help balance the amount of force on leg joints. Strong hip and core muscles are important during walking or running. Your physical therapist will assess these different muscle groups and compare the strength in each limb. They will prescribe specific exercises to target your areas of weakness.

Manual therapy. Your physical therapist will gently move your muscles and joints. This manual (hands-on) therapy can target areas that are difficult to treat on your own. These methods can help restore normal joint motion, flexibility, and strength. Physical therapists trained in manual therapy, and who have experience treating people after an MPFL injury, know the movement techniques that are safe to use, or to avoid. The right manual therapy techniques are a very important part of treatment after surgery.

Modalities. Your physical therapist may recommend ice and heat treatments. These modalities can help manage your pain.

Bracing. Compression sleeves around the affected joint may help reduce pain and swelling. Braces for people with too much kneecap motion provide extra support through a special pad around the kneecap. Your physical therapist can help you get the right kind of knee brace if needed. If you have surgery, you may need a brace to control knee movement as your postsurgery program progresses. A brace will keep the knee straight for the first several weeks after surgery.

Activity guidance. Your physical therapist will help you return to activities in a safe and structured manner. They will use your symptoms as a guide to design a program that protects your knee joint as it heals. Your physical therapist will consider each stage of healing. They will recommend appropriate exercises at each stage to maximize the health of your knee joint.

If Surgery Is Needed

For some cases, conservative treatment options may not resolve MPFL injuries. Also, if you have other related knee injuries at the same time, this may indicate the need for surgery. The goal of surgery is to restore the injured ligament so it can stabilize the knee. There are many factors to consider when determining the type of surgery, including:

  • The nature of your condition.
  • Your age.
  • Your desired activity level.

If needed, your physical therapist will refer you to an orthopedic surgeon to discuss your options.

If you have surgery to reconstruct your MPFL, you will spend several months in physical therapy afterward. Using the treatments described above, your physical therapist will help you progress through the stages of recovery to restore:

  • Normal range of motion.
  • Strength.
  • Knee function.

Physical therapists know when and how to help patients safely progress and recover after surgery. Your physical therapist will work closely with your surgeon to help you achieve full recovery based on your condition and goals.

Can This Injury or Condition Be Prevented?

With knee injuries and conditions, some factors can be controlled and others cannot. Some MPFL injuries result from a traumatic event, such as a sports injury, and may not be preventable.

Some people with excess joint or ligament looseness (laxity) may experience an MPFL injury. This type of injury can occur when the ligament is too flexible.

When this is the case, the ligament cannot stabilize the knee joint during activity. Physical therapists help people properly strengthen their leg muscles to prevent such injury. Strong leg muscles help to support the structures around the knee.

If you have very flexible joints and have knee pain, stop any activity that causes pain. Contact your physical therapist immediately.

Your physical therapist will help you know when it is safe to return to your previous activity levels. They help to ensure your knee can handle the demands of physical activity, to avoid further injury. They also will guide you on which activities to choose and which to avoid. Your physical therapist will prescribe a home exercise program to help you maintain any improvements you’ve gained with treatment.

What Kind of Physical Therapist Do I Need?

All physical therapists are prepared through education and clinical experience to treat a variety of conditions or injuries. You may want to consider:

  • A physical therapist who is experienced in treating people with orthopedic or musculoskeletal injuries.
  • A physical therapist who is a board-certified clinical specialist or who has completed a residency in orthopedic or sports physical therapy. This physical therapist will have advanced knowledge, experience, and skills that apply to athletes.

You can find physical therapists in your area with these credentials and clinical expertise on Find a PT, a tool built by the American Physical Therapy Association.

General tips when you're looking for a physical therapist (or any other health care provider):

  • Get recommendations from family, friends, or other health care providers.
  • Ask about the physical therapists' experience in helping active individuals with knee pain before you make an appointment.
  • Be prepared to describe your symptoms in as much detail as possible, and report what activities make your symptoms worse.

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The American Physical Therapy Association believes that consumers should have access to information to help them make informed decisions and prepare them for their visit with a health care provider.

The following resources offer some of the best scientific evidence related to physical therapy treatment for medial patellofemoral ligament injuries. They report recent research and provide information on the standards of practice both in the United States and internationally. They link to a PubMed* abstract (which also may offer free access to the full text) or other resources. You can read them or print out a copy to bring with you to your health care provider.

Dall'Oca C, Elena N, Lunardelli E, Ulgelmo M, Magnan B. MPFL reconstruction: indications and results. Acta Biomed. 2020;30;91(4-S):128-135. Article summary on PubMed.

Manske RC, Prohaska D. Rehabilitation following medial patellofemoral ligament reconstruction for patellar instability. Int J Sports Phys Ther. 2017;12(3):494-511. Article summary on PubMed.

Tanaka MJ. The anatomy of the medial patellofemoral complex. Sports Med Arthrosc Rev. 2017;25(2):e8-e11. Article summary on PubMed.

Baer MR, Macalena JA. Medial patellofemoral ligament reconstruction: patient selection and perspectives. Orthop Res Rev. 2017;9:83-91. Article summary on PubMed.

Ries Z, Bollier M. Patellofemoral instability in active adolescents. J Knee Surg. 2015;28(4):265-277. Article Summary on PubMed.

Arendt EA, Moeller A, Agel J. Clinical outcomes of medial patellofemoral ligament repair in recurrent (chronic) lateral patella dislocations. Knee Surg Sports Traumatol Arthrosc. 2011;19(11):1909-1914. Article Summary on PubMed.

Fisher B, Nyland J, Brand E, Curtin B. Medial patellofemoral ligament reconstruction for recurrent patellar dislocation: a systematic review including rehabilitation and return-to-sports efficacy. Arthroscopy. 2010;26(10):1384-1394. Article Summary on PubMed.

Arendt EA, Fithian DC, Cohen E. Current concepts of lateral patella dislocation. Clin Sports Med. 2002;21(3):499-519. Article Summary on PubMed.

*PubMed is a free online resource developed by the National Center for Biotechnology Information. PubMed contains millions of citations to biomedical literature, including citations in the National Library of Medicine's MEDLINE database.