How does an MRI measure Trochlear dysplasia?

How does an MRI measure Trochlear dysplasia?

1. the ratio between medial versus lateral trochlear facet length calculated as (medial facet) / (lateral facet) is one way to calculate it 8
2. a ratio of <40%, in this case, indicates trochlear dysplasia.

How is MRI Trochlear depth measured?

To calculate trochlear depth the distance from the trochlear groove from the before mentioned tangent is subtracted from the average of the two distances between the medial and lateral facet and that tangent 2.

What is mild Trochlear dysplasia?

Instead of a groove, some patients have a flat or a dome-shaped trochlea. This condition is called trochlear dysplasia. When an individual has a flat or dome-shaped trochlea, the patella loses stability and can track to the outside of the knee as the knee bends.

Do you need surgery for Trochlear dysplasia?

In cases where the patella instability is affecting patient’s lifestyle, surgery is warranted. The procedure to restore the normal trochlear anatomy is an open surgery called a trochleoplasty. The aim is to deepen the trochlear groove, so the patella sits back into the correct configuration.

How is Trochlear dysplasia measured?

Where is Trochlear depth measured?

The trochlear depth is calculated by measuring the mean of the maximum anteroposterior (AP) distance of the medial and lateral femoral condyles minus the distance between the deepest point of the trochlear groove and the line paralleling the posterior femoral condyles surfaces (Fig. 1).

Can you fix Trochlear dysplasia?

Patients who have a lateral patellar dislocation have a much higher risk of recurrence when they have trochlear dysplasia. Because the severity of trochlea dysplasia can run from minor to severe, treatment options are also varied.

How many people have Trochlear dysplasia?

Trochlear dysplasia has been shown to be present in < 2% of the population but in over 85% of people with recurrent patellofemoral instability.

Is Trochlear dysplasia bilateral?

Orthopedic surgeons who encounter patients presenting with chronic patellar instability with no underlying disease or syndrome should be aware of the presence of femoral trochlear dysplasia leading to recurrent bilateral patellar dislocation.

What is Trochlear?

: an anatomical structure that is held to resemble a pulley especially : the articular surface on the medial condyle of the humerus that articulates with the ulna.

Is Trochlear dysplasia rare?

Severe cases of trochlear dysplasia are rare, whereas more mild cases where the trochlear groove may be flatter than normal, are not that uncommon. Therefore, it is a relatively common condition, but often does not cause significant problems when it is a milder case of trochlear dysplasia.

What is Trochlear cartilage?

The patella rests in a groove on top of the femur called the trochlear groove. When you bend and straighten your knee, the patella moves back and forth inside this groove. A slippery substance called articular cartilage covers the ends of the femur, trochlear groove, and the underside of the patella.

How is floor measured in MRI for trochlear dysplasia?

MRI Assessment of Trochlear Dysplasia. To compute the final metric, the floor measurement is subtracted from the average of the two facet measurements. The average of the two facet measurements may be interpreted as the length of a line parallel to and equidistant from the two facet measurements (red dotted line).

How can I tell if I have trochlear dysplasia?

With axial images provided by CT or MRI, trochlear dysplasia can be confirmed in the presence of a variety of abnormal measurements: the lateral trochlear inclination may be decreased, the sulcus angle increased, the lateral facet asymmetrically widened, or the central trochlear anteroposterior measurement increased.

What is the sensitivity of the femoral trochlear?

The ventral trochlear prominence between the supratrochlear femoral cortex and the most ventral point of the trochlear floor (midsagittal section) was always larger than 6.9 mm in dysplastic trochleae. A facet ratio of less than 2:5 (medial to lateral) 3 cm above joint space level had a sensitivity of 100% and a specificity of 96%.

What kind of dysplasia is the femoral trochlea?

Trochlear dysplasia refers to a pathologic alteration in the shape of the femoral trochlea.