- Department of Neurosurgery, Universita’ Politecnica delle Marche, Umberto I General Hospital, Ancona, Italy
Department of Neurosurgery, Universita’ Politecnica delle Marche, Umberto I General Hospital, Ancona, Italy
DOI:10.4103/2152-7806.105100Copyright: © 2012 Rienzo AD This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
How to cite this article: Rienzo AD, Iacoangeli M, di Somma LG M, Alvaro L, Niccolò Nocchi, Scerrati M. Shape modifications of porous hydroxyapatite prostheses to improve rigid implant fixation: Experience in 12 cases. Surg Neurol Int 26-Dec-2012;3:161
How to cite this URL: Rienzo AD, Iacoangeli M, di Somma LG M, Alvaro L, Niccolò Nocchi, Scerrati M. Shape modifications of porous hydroxyapatite prostheses to improve rigid implant fixation: Experience in 12 cases. Surg Neurol Int 26-Dec-2012;3:161. Available from: http://sni.wpengine.com/surgicalint_articles/shape-modifications-of-porous-hydroxyapatite-prostheses-to-improve-rigid-implant-fixation-experience-in-12-cases/
Background:Various methods of fixation have been described for custom made hydroxyapatite cranial implants. Their poor malleability limits most of the common used fixation techniques because of the high risk of cranioplasty's fracturing or higher exposure to infections. We present our experience with a new fixation technique, based on an appositely premodified hydroxyapatite implants.
Methods:In a 2-year time period, 12 patients underwent cranioplasty by a modified custom made porous hydroxyapatite implant. Once the three-dimensional computer model of the prostheses was performed, three semicircular extensions placed at strategic positions were drawn and the final prosthesis was realized. At surgery, holes fitting the extensions were drilled into the skull borders and the implant was easily embedded inside the defect. Small titanium meshes overlying the extensions were fixed by screws to the surrounding bone.
Results:A minimal increase of operative times was recorded, with drilling and fixation requiring additional 30 and 15 minutes, respectively. Optimal contact between cranioplasty and skull borders was always observed at control computed tomography (CT) scans. Permanent rigid fixation was obtained in all cases, with good functional and aesthetic results at follow-up.
Conclusions:Modifications of hydroxyapatite implants are obtained without additional costs. The minimal increase of operative times is largely counterbalanced by optimal fixation results. Finally, the bone drilling and the immediate proximity of bone to prosthesis might enhance the potential for osteogenesis and osteointegration.
Keywords: Bone fixation, decompressive craniectomy, hydroxyapatite cranioplasty, osteointegration, prostheses
In recent years, the increased number of decompressive craniectomies performed all over the world has led to a proportional increase of reconstructive surgeries for cranioplasty.[
Most of the available materials may be fixed to the skull defect by the use of titanium miniplates and screws. This is not possible when using porous hydroxyapatite, whose poor malleability implies a high risk of implant's fracturing during fixation with self-drilling screws.[
We present our experience with the use of an appositely premodified hydroxyapatite prosthesis that allows an optimal rigid implant fixation, a good aesthetic results, and no significant increase in the complexity and duration of the cranioplasty procedure.
In a 4-year time period, from July 2007 to July 2011, 22 cranioplasty procedures were performed at our Institution by the use of custom made porous hydroxyapatite implants. The use of these prostheses was needed because of autologous bone resorption in 17 cases and bone infection in 5. During the first year of this series, five prostheses were implanted and fixed to the skull defect using doubled nylon or silk sutures [
The drilling of the skull borders needful to create the niches where to allocate the implant's extensions required from 20 to 30 minutes of additional operative time and it was always safely performed, with no injury to the dural layer and underlying brain. Mesh shaping and fixation required further 15 minutes. Perfect implant fitting was obtained in all cases. No postoperative complications were recorded. Satisfying functional and aesthetic results were always reported at follow up evaluations (follow up range: 12-36 months).
The number of surgical procedures aimed at repairing the skull defects has increased proportionally to the diffusion of decompressive craniectomy. Cranioplasty is mandatory to re-create a physiological intracranial compartment, to protect the brain from external insults, and cerebrospinal fluid (CSF) disturbances, and to restore a cranio-facial symmetry. Even though repositioning of the autologous bone is considered the best treatment for such defects, long-term complications, such as bone resorption or infection, may determine the need for further reconstructive surgeries.[
1. Aarabi B, Hesdoffer DC, Ahn ES, Aresco C, Scalea TM, Eisenbergh HM. Outcome following decompressive craniectomy for malignant swelling due to severe head injury. J Neurosurg. 2006. 104: 469-79
2. Di Rienzo A, Iacoangeli M, Rychlicki F, Veccia S, Scerrati M. Decompressive craniectomy for medically refractory intracranial hypertension due to meningoencephalitis: Report of three patients. Acta Neurochir (Wien). 2008. 150: 1057-65
3. Eppley BL, Hollier L, Stal S. Hydroxyapatite cranioplasty: 2. Clinical experience with a new quick setting material. J Craniofac Surg. 2003. 14: 209-14
4. Gooch MR, Gin GE, Kenning TJ, German JW. Complications of cranioplasty following decompressive craniectomy: Analysis of 62 cases. Neurosurg Focus. 2009. 26: E9-
5. Hardy H, Tollard E, Derrey S, Delcampe P, Peron JM, Freger P. Tolérance clinique et degré d’ossification des cranioplasties en hydroxyapatite de larges defects osseux. Neurochirurgie. 2012. 58: 25-9
6. Honeybul S. Complications of decompressive craniectomy for head injury. J Clin Neurosci. 2010. 17: 430-5
7. Joffe J, Harris M, Kahugu F, Nicoll S, Linney A, Richiards R. A prospective study of computer-aided design and manufacture of titanium plate for cranioplasty and its clinical outcome. Br J Neurosurg. 1999. 13: 576-80
8. Matukas VJ, Clanton JT, Langford KH, Aronin PA. Hydroxyapatite: An adjunct to cranial bone grafting. J Neurosurg. 1988. 69: 514-7
9. Sai CL, Chieh TW, Shih TL, Po JC. Cranioplasty using polymethyl methacrylate prostheses. J Clin Neurosci. 2009. 16: 56-63
10. Staffa G, Barbanera A, Faiola A, Fricia A, Limoni P, Mottaran R. Custom made bioceramic implants in complex and large cranial reconstruction: A two year follow-up. J Craniomaxillofac Surg. 2012. 40: e65-70
11. Staffa G, Nataloni A, Compagnone C, Servadei F. Custom-made cranioplasty prostheses in porous hydroxyapatite using 3D design techniques: 7 years experience in 25 patients. Acta Neurochir (Wien). 2007. 149: 161-70
12. Stoodley MA, Abbott JR, Simpson DA. Titanium cranioplasty using 3-D computer modeling of skull defects. J Clin Neurosci. 1996. 3: 149-55