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This is Pediatrics week 2 case number

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five. The diagnosis were considering is developmental dysplasia

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of the hip.

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And the image you see is of a hip ultrasound

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now hip ultrasound is a very sensitive and specific

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way to evaluate for ddh or developmental dysplasia

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of the hip. However, it's only possible

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when there is a predominant cartilaginous.

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appearance of the femoral head and trochanter

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once the child has grown and ossified these

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structures the bone shadows out the image and radiograph

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is required but for younger patients

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Let's say around the first few months of

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Life ultrasound is an extremely effective way to make this

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diagnosis. And as you know, if you've ever performed one

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of these ultrasounds yourself, it can be quite challenging to

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obtain diagnostic images. You have a moving child

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laying up on their side and you're trying

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to find the perfectly straight and best window

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with your probe. So if you are the

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person interpreting the images, how do you know if it was

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obtained in the way they can give you

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confidence in your diagnosis and there are three rules of thumb when

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you're evaluating an image. The first is you

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want to identify as straight as you

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can the edge or margin of the iliac bone.

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Here's the roof of the acetabulum coming down, but

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it's this line here that you really want to

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be straight ours here isn't perfectly straight, but it's

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close. So that's Point. Number one. Number two, you

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want to visualize the cartilage of the greater

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trochanter and that's what we see here if

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Out of plane anterior or posterior, you won't see that

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cartilage. But once you see it, there's confidence. That's

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Point. Number two. Number three, you want to see early

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ossification of the tri-radiate cartilage, which

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should be at the pit or the deepest portion of

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the acetabulum and just a little bit of echogenic

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line from that ossification of

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the tri-radiate cartilage. That's Point number three, when we see all

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three of these we can have confidence that

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our image is of diagnostic quality and

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we can make the diagnosis. So now that we feel good about

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these images. Let's go ahead and take a look at what

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they measured because of course when it comes to hips angles matter.

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And we're going to perform a couple of measurements first. We're

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going to evaluate for the

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percent coverage of the femoral head.

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So we've drawn a circle around the cartilage of the femoral head. We've

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continued the line of the iliac bone just

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to orient you don't forget that over

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here is superior.

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Here is inferior. This is the lateral margin

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of the bone. And then if we move this direction, we'd

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be moving towards the center of the pelvis. We've drawn

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this circle what percent of this circle is below

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the Horizon so to speak and the answer which

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we can barely see on our image is 55 to

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56 percent. So that's great.

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That's exactly what we want to see. So let's move ahead

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to the angles here. We've drawn angular Lines continuing the

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iliac bone, but also the roof of

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the acetabulum and calculating an alpha and a beta

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angle and for the purposes of diagnosis. We're most interested in

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this Alpha angle, which is 61.8 that's

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above 60 which is kind of our cutoff for

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ddh the percent coverage of

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the femoral head if you recall was 55 56 that's

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above 50% That's our cutoff. So

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this is a normal appearing hip now. Let's

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go over to the other side after we've scrolled through

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the transverse dimensions and

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Is the left hip and what we're seeing here

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is a little bit of a dip in the bone. So

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this image is not quite as well obtained also very

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vague.

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Ossification down here. I would like a better image before

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I perform. My measurements Let's Straighten out that hip.

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That pelvic line that's good. And here we've

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drawn around our cartilaginous femoral head

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and you don't even need to look at the numbers, you know that less than

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50% of that circle is below the Horizon. This

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is a very dysplastic sub locks tip.

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In fact, it's so sub blocks. It's almost completely dislocated. This

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is only 16 17% covered

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not good enough. This is developmental dysplasia

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of the hip do I need an angle? No, but

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it's part of our diagnostic criteria. Let's get an angle 30

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degrees of alpha 32 degrees.

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That's not good enough. Not 60 by a long

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shot. So this is normal right hip but developmental

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dysplasia of the left hip you can use

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the graph grading scale and follow that up. You need

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to know the age of the patient greater than or less than

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those first few months of life, and then you can rate the severity.

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If the patient is getting an exam for the first time you will

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often want to perform.

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Some stress Maneuvers to see if the hip tries to dislocate

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if the patient's already being treated or they already

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have known. Ddh. You may not want to do the stress

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maneuver. So that's sort of a decision. You need to make per patient.

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But even without stress Maneuvers, we know we've got

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problems on the left here and that's the end of the case.