Injectable Cranioplasty

Q: Dr. Eppley, I had an injectable cranioplasty procedure done last year by another doctor. The results were less than stellar. The size is small, approx 1″ x 3/4″. I have the following questions:
1) is it possible to burr the implant down through the original 1/2″ incision
2) will the rasping damage the hairs above the site
3) is there risk of cracking the implant

Thanks in advance for your response.

A: An Injectable cranioplasty, even when small, is prone to irregularities and edging. It takes a lot of practice and negative outcomes to work the kinks out of this procedure because it is done in a blind fashion. What material was injected? (I will assume PMMA)

In answer to your questions:

1) It is not possible too smooth out the material through the small incision by which it was placed. That is the downside to an injectable cranioplasty. If the result isn’t perfectly smooth the incision will have to be enlarged to modify/remove it.

2) If it is PMMA or even hydroxyapatite (HA), you can not rasp it or smooth it. PMMA is too hard and HA is too brittle for rasping. They have to be burred down for further contouring. In many cases, you are better off removing it and replacing it.

3) The implant will fracture/crack with any type of closed manipulation such as rasping or burring.

Dr. Barry Eppley
Indianapolis, Indiana