Q: Dr. Eppley, I lost my frontal, temporal, parital skull due to an accident. My surgeon used peek polymer for a skull reconstruction. I am not pleased with the sides and it feels like screws are sticking out all over and hurts. I’m not sure what to expect from such a large cranial reconstruction and if anything can be done from your point of view?
A: Regardless of the material used, large cranial reconstructions almost always will result in some amount of plate and screw palpability. This is not usually seen for many months afterwards until all the swelling has subsided and the scalp tissues have contracted down and around the implant and the plates and screws used to secure it. This because particularly so on the sides of the head where the temporal muscle thickness is lost due to atrophy and loss of attachments to create classic temporal hollowing after any type of craniotomy/replacement.
I will make the assumption that the PEEK implant has a perfect fit to the surrounding bone because it was made from a 3D CT scan. (although often there is some edge demarcation between the bone and the implant) Almost all of these type of cranial reconstructions can be aesthetically improved through plate and screw removal, bone cement to smooth over any transition areas and fat grafting to create a thicker interface between the skin and the bone for temporal augmentation.
How any of these secondary reconstructive techniques may be applied to you would require an assessment of your exact condition through an analysis of any pictures that you can send.
Dr. Barry Eppley
Q: Dr. Eppley, I had a skull reconstruction due to a golf ball size defect on the back of my head where the bones meet. I had a Medpor implant placed and it had gotten infected and then caused a skull osteomyelitis. I’ve been told that only fat grafting now is the only treatment option. What about antibiotic PMMA cement? Is there a risk of infection?
A: The most logical next step for skull reconstruction of an occipital skull defect after an infection with Medpor would be antibiotic-impregnated bone cement. Medpor has a notorious history of infection while PMMA bone cement does not. As long as the overlying scalp tissue is adequate thickness and normal vascularity (not been irradiated), PMMA bone cement should have a low risk of infection even with the history of a prior osteomyelitis. I don’t know if what you had constitutes a true osteomyelitis (bone infection) or whether this was more of an implant infection. (which is more likely) Either way PMMA bone cement has a long history of successful use in neurosurgery and orthopedic surgery in bone infections. The slow release of antibiotics from the impregnated cement continues for weeks after surgery.
Dr. Barry Eppley
Q: Dr. Eppley, my son is 5 years old and has undergone a craniectomy of the right parietal skull bone which is quite large when he was 4 years old. We want to know which cranioplasty procedure would be best for him, bone cement or autologous bone transplant from the adjacent side of the skull? He is otherwise neurologically fine with no functional or developmental deficits.
A: To give a very specific answer as it relates to your son, I would need to know some more information about his defect including reviewing a CT scan and see pictures of him. But I can make some general comments about skull reconstruction in children. When you have large skull defects in young children, the reconstuction options are somewhat more limited because you really don’t have the ability to use a cranial bone graft. While a cranial bone graft, what you call an autologous bone transplant, can be done you essentially would be ‘robbing Peter to pay Paul’ do to speak. In children the skull is not think enough to harvest a split-thickness cranial graft. This using a cranial bone graft just creates the same problem you are trying to solve somewhere else. Thus one is forced to use a variety of synthetic methods for the skull reconstruction. These could include bone cements (resorbable and non-resorbable), metal meshes (one I wouldn’t do), and a assortment of synthetic implant material that are either preformed or custom-made from a CT scan. (e.g., HTR-PMI) There are advantages and disadvantages to all of these synthetic approaches and that needs to be discussed on an individual case basis.
Dr. Barry Eppley
Q: Dr. Eppley, I have a depressed skull fracture as a result of a head butt injury. What are my options for reconstruction?
A: While I don’t know the location or exact extent of your depressed contour skull deformity, it is highly likely that an onlay cranioplasty procedure can completely restore the shape of the skull. Material can always be added to build the bone back to a normal contour and there are multiple options to do so including polymethylmethacrylate (PMMA) and a variety of hydroxyapatite formulations. This is actually a fairly simple procedure that is very effective. The only significant question is as to what incisional approach can be used to adequately perform the cranioplasty. Without knowing where the exact location and size of the skull issue i, I could not answer that question. I would be able to answer that question better if you could send me a picture of the depressed skull area.
Q: Dr. Eppley, I have a dermoid cyst in my forehead bone that needs to be removed. Because of its size, it will leave a significant bone defect after its removal so it will need to be reconstructed. One plastic surgeon told me that he has to take out too many bad products from people’s head’s so he now only uses a titanium mesh covering for these repairs. My question is which is a better method for reconstruction, metal mesh or a bone filler? Also, two different incisions have been discussed. Since the lesion is not too far from the hairline, is it possible to do a smaller incision, one that goes from the sideburns to the midline of the forehead and just very slightly into the hair line? I know that a bicoronal incision can be used but it is a more difficult recovery and some scalp numbness will result. Which incision would be better to perform the surgery with the least risk of problems?
A: It appears that you have an epideroid cyst in the diploic space of the frontal bone. I assume the reason for its removal is that it is slowly growing.
I have no picture of you to see where exactly the lesion is located in reference to your frontal hairline so it is impossible for me to comment on what incisional approach could be used. Certainly some variation of the bicoronal incision can be used. The only question is whether some other form of more limited incisionall approach could be used. Without knowing where on the forehead it is (seeing a picture with a mark on your forehead), I can comment no further.
In terms of reconstruction, I would disagree strongly with the idea that there are a lot of bad products for skull reconstruction. I have used all available materials and have never had a problem with any of them in hundreds of cases. They all work well when used with proper technique. For covering a ‘crater’ in the forehead after the cyst removal, I absolutely would go with an hydroxypatite cement. It can fill in the defect and make the forehead perfectly smooth. While covering the defect with low profile plates and screws is also acceptable, there is always the chance that you will be availble to feel the outline of the metal hardware and even some risk that it may leave a negative image on the forehead skin should it thin out after the surgery.