CRANIOPLASTY PERFORMED WITH A NEW OSTEOCONDUCTIVE, OSTEOINDUCING HYDROXYAPATITE-DERIVED MATERIAL

Object. Cranioplasty is required to protect underlying brain, correct major aesthetic deformities, or both. The ideal material or this purpo se is autogenous bone. When this is not available, alloplastic or arti ficial materials may be used. These materials should be malleable, str ong, lightweight, inert, noncarcinogenic, nonferromagnetic, and, if po ssible, inexpensive. The authors reviewed their surgical experience wi th a new bone substitute and discuss outcomes in patients in whom it w as used. Methods. The 11 patients presented in this series had bone de fects resulting from bone-involving tumor (eight cases), trauma (two c ases), or aesthetic deformity due to repeated craniotomies (one case). The defects were repaired using Osprogel, a bone substitute that cons ists of calcium hydroxyapatite combined with synthetic, human bone-der ived gelatin, glycerol, and water. Osprogel is not only a bioinert mat erial but also an osteoconductive and osteoinducing substrate; when it is placed in contact with healthy cancellous bone, it induces osteoge nesis and angiogenesis, thus permitting the regrowth of nearly normal bone. The sheet of Osprogel was modeled onto the cranial defect intrao peratively and was kept in place either by using a titanium micronet s ecured to surrounding bone with microscrews (first two cases) or by us ing a single- or double-layer titanium mesh secured with stitches. No complications due to the procedure were observed. The results, evaluat ed at least 6 months after surgery by using three-dimensional (3-D) re constructed computerized tomography scans, were excellent in seven pat ients, good in three, and fair in one. In the patient with a fair resu lt, the repair was unsatisfactory because there was lack of experience in using the material. In part of the area to be repaired, the Osprog el was used as filler; here it was washed out and resorbed. The cases deemed as having a good result had good bone replacement; however, the curvature was faulty. Conclusions. In the near future, this technique may be refined to achieve good or excellent results either without th e use of supporting material or with the use of individual, computer-d esigned 3-D prostheses.