Is there an ideal "angle"?

[Miguelito]

Sorry to be posting another question so quickly. And yes it's the middle of the night. My body decided it needed a three hour nap this afternoon after I put my three year-old down, so there you go.

Dr. Gross gave me a nice x-ray of my implant that showed a line and a 31 degree angle of inclination (I think). I know in my pre-surgery research I saw that the goal was an angle of under 55 degrees, but I have no idea what 31 degrees should mean to me. Can anyone shed some light?

In the interest of full disclosure I must say that pre-surgery I would have scoured the web for hours looking for an answer to a question like this, but now I'm just curious.

Thx,

Mike

[obxpelican]

I've read a number of articles where the range should be 40-42 (+-) 10 to 12 degrees.

So anywhere between 50 and 30 depending on who wrote the article.  From what I understand when it's steep like 60+ it's worse for you but I guess too shallow could be bad too.


Chuck

[bluedevilsadvocate]

From what I have read, there may be some uncertainty.  But, here is an abstract published in 2010 in the British The Journal of Bone and Joint Surgery; the authors suggest that the optimal inclination is 45 degrees + or - 10 degrees:

http://www.bjj.boneandjoint.org.uk/content/92-B/8/1072.abstract

[bluedevilsadvocate]

Here is what Dr. Harlan Amstutz wrote in a letter to the editor published in the February, 2012 edition of Orthopedics Today:

"After analysis of our 1350 Conserve Plus Hips (Wright Medical Technology), a safe zone was produced for all sizes suggesting 42° ± 10° of abduction angle and a 15· ± 10· of anteversion angle, which I believe represents a target well within reach for an experienced surgeon."

[obxpelican]

What you have to remember, some devices will be slightly different in what each surgeon thinks is a nominal angle for inclination and anti.

For instance, the ASR if that was not pretty exact you were screwed.


Chuck