Thread by @UTSW_MSK

Hip dysplasia measurements 101!

A #gif #tweetorial below.

Hips are very important for stability and handle a lot of tensile force

Unfortunately dysplastic hips don’t have complete coverage of the joint which can lead to extra stress, labrum tears as well as cartilage loss.

To fix dysplastic hips, there are many surgical or physiotherapy options and a lot of these are guided by advanced imaging. We routinely do 3D segmentations for CTs of the hips 👇
Frontal 3D re-con can also eval for pelvic tilt. Normal values: Men - 2-3mm; Women - 3-4mm

Also look at the up-sloping acetabulum roof, a finding commonly seen in hip dysplasia

The first measurement is the Tonnis angle with normal values 4-10 degrees. Great values suggest dysplasia and lower suggests overcoverage.

Then is the center edge angle with normal values 25-39 degrees. 20-25 is borderline, 15-20 is mild, less than 15 is moderate to severe dysplasia. Greater than 39 is over-coverage.

We move to AP center edge angle, where 20-40 degrees is normal. Greater than 40 is overcoverage and less than 20 is under coverage

Another important measurement is the neck shaft angle with normal 120-140. Less than 120 is Coxa Vara and greater than 120 is Coxa Valga

The second last is acetabular version, but the pelvic tilt angle is measured before measuring acetabular version

Measuring the pelvic tilt angle👆allows us to correct for acetabular version👇

And finally femoral version. We measure knee angle first at the level of the femoral condyles👇

And then use it to correct for femoral version below

These gifs were created from the tutorial by our chief @AChhabraMD at @UTSWMSK @UTSW_Radiology! We routinely collaborate with our wonderful @utswortho team including @joelwellsmd for the care of our hip dysplasia patients!

Check it out here 👇