What Is Your Experience With HTR Cranial Implants?

Q: Dr. Eppley, I am interested in an HTR cranial implant replacement. (or maybe one made of PEKK)  I suffering a stroke in April which required a decompressive craniotomy. The removed cranial bone flap was finally reinserted 6 weeks later but then it got infected which required a heavy course of antibiotics and subsequent removal of it. I am now seeking to replace it with an alternative.

I have been in contact with Biomet, and as far as my understanding goes, they are able to make an exact replica of my skull from an MRI image and also that the bone cells actually adhere to this material.  Please confirm.

If you could share with me your experience regarding these materials, including but not limited to length of time you have been performing this surgery, risk, success rate, recovery time, cost, risk of flying with a bone flap, how long I would be under your care, how soon I could anticipate the surgery and anything else that I may have missed, I would very much appreciate it.

A: My experience with cranial implants and HTR cranial implants specifically is considerable. Understand that PEKK is a different material and manufacturing process and offers no advantages in cranial implants in my opinion, most importantly it is not a porous material that creates interconnect porosity. I have worked with Biomet since 1991 on HTR-PMI and have done many cases since, both cranial and otherwise. The HTR material and its composition does offer excellent tissue ingrowth and direct bone bonding to it. (I did the original research in 1995 that substantiates those tissue effects to it) As a synthetic replacement for cranial bone, it offers the best material properties in my opinion. Of the many I have placed i have yet to have an infection or the need to remove one from any complications.

While I don’t know the exact location of his cranial bone flap loss, the replacement surgery is fairly straightforward. A 3D CT scan is obtained from which an exact patient model is made. From the model, an exacting HTR cranial implant is made. Surgery involves reopening the scalp incision and inserting it into position, which usually has a good fit and rarely requires any intraoperative modification. The implant is then secured into place by small plates and screws and the incision closed. Depending upon the size of the defect and the patient’s physical health, it could be either an outpatient or overnite stay at the longest. The patient could return home within 48 hours and there would be no problem flying with a new cranial implant in place. Neither implant or the small titanium plates and screws are detectable in airport scanners. (do not set them off)

Dr. Barry Eppley

Indianapolis, Indiana