The Crasheteria

The Crasheteria

A few weeks ago, I presented a short seminar to claims managers and attorneys at several major insurance companies on a subject I termed “Crasheteria” (A portmanteau of Crash and Cafeteria).

Because many auto-related crashes result in orthopedic conditions that have unique and descriptive names that sound like something one might find on a vintage cafeteria menu board, I thought it might be interesting to merge both; classic cafeterias and classic conditions found in auto accidents.

As we enter the world of Crasheteria, we find a menu of items with unique names that are specific to motor vehicle accidents.

First Item: Dashboard Knee

In Part I of the Crasheteria series, the first condition we find on the menu is “Dashboard Knee.”  This condition is caused when the knee strikes the dashboard with force. Not unlike something one might experience if the front of a person’s knee was struck violently with a sledge hammer.

The force causes the undersurface of the kneecap (patella) to undergo a process of degradation, called chondromalacia, which can result in symptoms 4 to 6 months after the car crash. Usually, the patient will have immediate pain and bruising to the anterior (front) portion of the kneecap that will resolve over 2 to 3 weeks. This is followed by a period of quiescence where the patient may exhibit no symptoms at all for 4-6 months, only to have symptoms return with-a-vengeance.

Typically, the patient will complain of pain to the front of the kneecap region that is made worse by going up or down stairs or inclines, and by sitting for long periods of time, such as inside a car or on an airplane, with the knee bent. Because there have been no symptoms for many months, it is neither unreasonable nor unusual for the insurance Claims Manager to conclude that the recurrence of knee pain is unrelated to the subject accident. However, this would misrepresent the notorious nature of Dashboard Knee.

Dashboard Knee causes the shiny white porcelain-like covering on the undersurface of the patella to undergo a pathological transformation called chondromalacia. This term literally means that the cartilage (chondro-) became soft (-malacia) because of the severe blow caused by the impact of the kneecap on the dashboard.

There are four grades of chondromalacia, each representing a more severe condition as depicted in the photographs from left to right. Grade 1, the least severe, occurs when the cartilage becomes so soft it can be indented with a surgical instrument. In surgery, we call this the “Pilsbury Dough Boy Sign.”  Grade 2 chondromalacia of the patella is characterized by fissures that cause the articular cartilage to shear. Grade 3 is known as a “crab meat” with small fronds hanging down. Grade 4 is “the fried egg” with the yellow region being exposed bone.

Diagnosing Dashboard Knee commences by obtaining a detailed history from the patient. Because there is frequently a long gap between the auto crash and the onset of chronic symptoms, there may be difficulty in connecting the dots.

Remember, there is a history of a motor vehicle accident whereby the occupant recalls one or both of their knees striking the dashboard with some force. After impact, the knee is typically painful, red, and swollen around the kneecap. There may even be bruising after a few days. The x-rays may be normal. MRI scans, if perfomed in the acute phase may be normal; but they may also show evidence of a bone bruise.

The acute symptoms almost always resolve in a matter of weeks (as most bruises/contusions normally do) and the patient goes about their normal daily activities without concern. Unfortunately, as is common, the painful chronic knee symptoms arise 4 to 6 months later. But this time, they do not abate.

Examination of the knee will typically be normal with respect to range of motion and stability testing. There are no meniscal signs and there is usually pain with patello-femoral compression. X-rays are still normal in the chronic phase. However, the MRI scans will now likely detect evidence of chondromalacia involving the patella or the trochlear groove (the femoral sulcus inside of which the patella slides around). Often, only one well-circumscribed area of the patella, or trochear groove, or even both is/are pathologic.

Treatment for Dashboard Knee is initially conservative, and may include anti-infammatory medication, physical therapy, knee bracing, and a home exercise program. Intra-articular steroid injections may be required. If conservative care fails, then an arthroscopic surgical procedure may be required to address the problem.

Outcomes are variable with Dashboard Knee. Most patients will improve and may have complete resolution of symptoms with treatment. However, some patients may have chronic symptoms that wax-and-wane.

Litigation often complicates matters because it invariably adds another variable. It is important for independent medical examiners, defense medical expert witnesses, and plaintiff medical expert witnesses to be fair and unbiased in their analysis.

If there is a clear and compelling cause-and-effect relationship between the car crash and Dashboard Knee, then it should be accepted as part of the claim. However, if such a clear and compelling cause-and-effect relationship between the car crash and Dashboard Knee cannot be established on the basis of the history, physical examination and imaging studies, then it should be rejected as part of the claim.

SUMMARY

• Dashboard Knee is a phenomenon that occurs in some car crashes when the bent knee strikes the dashboard with force.

• In the acute phase, the patient complains of knee pain, swelling, redness, and bruising that is consistent with a contusion. Symptoms typically resolve in 2-4 weeks.

• There is a “Gap of Quiescence” that lasts 4-6 months where the patient is symptom-free.

• The “Gap of Quiescence” is followed by a chronic phase where symptoms around the kneecap become more bothersome.

• Diagnosis is based primarily on history. MRI in the acute phase (if done) may show a bone bruise around the kneecap.

• MRI in the chronic phase may show evidence of chondromalacia around the kneecap.

• Conservative treatment is usually successful, but occassionally surgery is required.

• Medical experts should use careful analsysis in the diagnosis of Dashoard Knee and its possible relationship to the subject car crash.