Acetabular Angle

[Lopsided]

There is much discussion as to what is the optimum angle for the acetabular component and what can go wrong if it is not the right angle. Well, how do you know what the angle of the acetabular component of your own device is? From your own x-rays, how do you measure it?

I assume the angle of my device is right, I certainly hope it is, and my surgeon describes it (his own work) as perfect. I am sure it is, but I would like to know exactly what angle it is at.

Pat, most of us have copies of our own x-rays. Could you put a section in your website explaining how to measure the angle of our own acetablar components, with examples of where to draw the lines and where to measure from.

Has anyone else got any suggestions too?

Thank you,

D.

[B.I.L.L.]

My doc pencilled a sraight line across the pelvis (he eyeballed that one) then extended a line from the straight edge of the cup until it crossed the horizontal line, then measured the angle.  That would be the angle looking staight on (steepness) I don't know how they measure the front to back angle.

[obxpelican]

D,

If DeSmet did your surgery I would not even measure it, don't worry.... that guy is like on automatic perfection all the time.  I would wager my house on it.


Chuck

[Lopsided]

If DeSmet did your surgery I would not even measure it, don't worry.... that guy is like on automatic perfection all the time.

Chuck,

In his reply to my e-mail six month x-ray he replied (in his usual succinct way) "x-ray looks perfect that is OK."

I am not worried about my angle, I just wanna know what it is. Merely out of interest.

I would wager my house on it.

I had to sell mine to afford it!

Dan

[John C]

I think that most surgeons, or their offices, will tell you, since they often measure it from x-rays taken during or after surgery, and it is likely to be written in the surgical record.
Just for fun, I did measure mine off of my x-ray, and came out within one degree of what Dr. Gross confirmed that it was. I came up with around 40 degrees, and he confirmed that it was 39.
I used the same approach mentioned earlier. I drew a line connecting across two matching points on each side of the pelvis, in order to establish the true horizontal,  and then drew a line along the flat lower edge of the cup, and extended it until it intersects the first line. (You may need to be able to draw on a surface that is larger than the X-ray). Then just measure that intersection angle, which gives you the angle of abduction. The more vertical your cup, the more that number would be greater than 45 degrees, the less vertical the cup, it may be less than 45. It could be argued that if you have any rotations in or around the pelvis, the horizontal line may be off a little, but it should be a pretty close reference.