Dashboard Knee Syndrome

dashboard knee syndrome

A dashboard knee injury often happens when a person is involved in a head-on collision and is not seat-belted or is seat-belted, but the momentum of the crash causes the knees to propel forward underneath the seatbelt and strike the dashboard of the automobile.

The most common injury that occurs in a dashboard knee injury is a posterior cruciate ligament injury, which is disruption or damage to the posterior cruciate ligament that generally, along with the anterior cruciate ligament, helps stabilize the knee in its proper alignment.  When the ligament is torn from direct trauma, the knee will be painful and unstable when attempting to walk on it.  Swelling of the knee is common after this type of injury.

The posterior cruciate ligament is an intra-articular ligament that attaches the femur to the tibia within the knee joint.  It forms an X arrangement within the anterior cruciate ligament so that both together are required to keep the knee in place.  Posterior cruciate ligament injuries are much less common than anterior cruciate injuries and usually only occur when there is direct trauma to the bent knee such as is seen in a dashboard knee injury.

Signs and Symptoms of a Dashboard Knee

When the dashboard knee injury leads to a posterior cruciate ligament tear, the symptoms can be the following:

  • Knee pain. This can be a pain at rest that is worse when trying to walk on the knee.
  • The knee may have a feeling giving way when putting pressure on it.  With posterior cruciate knee injuries, you can still ambulate on the leg, but there is a gradual worsening of symptoms as time goes on and you continue to walk on the knee.
  • The swelling is usually caused by bleeding into the knee and occurs immediately following the posterior cruciate ligament tear.

Causes of a Posterior Cruciate Ligament Tear

The posterior cruciate ligament is usually torn in those situations when the proximal tibia (the shin bone) is struck just below the knee joint itself, rupturing the ligament.  This most commonly happens in a motor vehicle accident when the knee hits the dashboard at high velocities.  Other causes of posterior cruciate ligament tears can be contact sports, including soccer and football.  In such cases, the athlete falls on the bent knee while the foot is tilted downward (dorsiflexed).

Because males are more likely to be involved in motor vehicle accidents and are more likely to play in contact sports, this type of injury is more common in this gender.  Often other parts of the knee are damaged, such as the anterior cruciate ligament and the cartilage of the knee.  If other parts of the knee are affected, long-term knee pain and knee instability can occur.  Years later, you are at a higher risk of getting an arthritic knee with a lifelong problem of knee pain and disability.

Diagnosis of a Dashboard Knee

A dashboard knee is best diagnosed by taking a very detailed history of the incident along with a thorough physical examination of the knee.  Doctors will feel for looseness of the joint or excess fluid in the joint due to bleeding from the damaged ligaments.  X-rays of the knee will show evidence of fracture of the kneecap or the proximal tibia and fibula but will not be able to see any damage to the posterior cruciate ligament.  A bony avulsion injury can sometimes be seen within the joint.  This happens when the ligament is torn at the level of the bone, tearing away a piece of the bone in the process.  This is also known as an “avulsion fracture” and is an intra-articular fracture that is treated much the same way as if the ligament itself were torn.

MRI scanning of the knee uses a strong magnetic field, a computer and radio waves to see what is going on with the bones and soft tissues within the knee.  In general, an MRI can quickly pick up on an intraarticular knee injury, particularly those involving the ligaments and cartilage.  Excess swelling in the knee can be identified through an MRI examination as well.

Arthroscopy may be necessary if the diagnosis still is unclear after MRI and regular x-rays.  This involves using a camera attached to a tube that is inserted into the joint after making small incisions in the skin overlying the joint.  The camera can see the ligaments directly and can tell the extent of the tear in the posterior cruciate ligament.  Any other joint damage can be seen as well using an arthroscope, including cartilaginous injuries.

Treatment of a Dashboard Knee Injury

In general, no surgery is required to repair a posterior cruciate ligament tear. Doctors will initially recommend the RICE Protocol, which stands for:

  • Rest. Staying off the leg for a period of a few days to a couple of weeks can allow the ligament to heal.
  • When ice is applied to the knee, the pain is better, and the swelling is kept to a minimum.
  • This can be accomplished by putting an ACE bandage around the knee to keep the swelling down.
  • This means keeping the knee up, preferably above the level of the heart to minimize swelling.

You can also take over the counter pain medications that also act as anti-inflammatory agents.  These include medicines that contain aspirin, ibuprofen or naproxen.  You may also undergo physical therapy in which knee strengthening exercises are used to build up the stability of the knee.  You may need crutches or a knee brace for a period of time, so you don’t use the knee very much while the posterior cruciate ligament heals.

Surgery may be necessary.  It may be as simple as having a joint aspiration, which takes off the excess blood and fluid from around the knee joint. In some cases, the procedure will have to be repeated because the fluid has built up again.

If you have other injuries to the knee, a fracture or a ligament that just won’t heal, knee surgery is sometimes indicated.  Most knee surgery is done using a laparoscope, which involves inserting a camera on the end of a fiber-optic tube to visualize the damaged structures and making other tiny incisions around the joint to manipulate and suture injured areas and to replace areas of cartilage that have become dislodged.

Sacramento Knee Injury Lawyers

I’m Ed Smith, a Sacramento Knee Injury Lawyer that can help in any acute knee injury accident. Call me anytime for free, friendly advice at 916-921-6400 or 800-404-5400. See on Reviews on Yelp, Avvo and Google. I’m a member of the Million Dollar Advocates Forum.