Costantino P D, Friedman C D, Jones K, Chow L C, Pelzer H J, Sisson G A
Department of Otolaryngology-Head and Neck Surgery, Northwestern University Medical School, Chicago, Ill.
Arch Otolaryngol Head Neck Surg. 1991 Apr;117(4):379-84. doi: 10.1001/archotol.1991.01870160033004.
Hydroxyapatite cement is a unique calcium phosphate preparation that can be shaped intraoperatively and sets in vivo to an implant composed of microporous hydroxyapatite. The histologic response to this cement was evaluated by implanting disks made of this material within the heads of nine cats. Three sets of 12 hydroxyapatite cement disks were produced containing 0%, 10%, and 20% macropores by volume, respectively. The disks were implanted subcutaneously, intramuscularly, above the periosteum of the skull, and directly onto the surface of the calvarium. Each macropore percentage was represented in each tissue plane, and animals were killed up to 9 months postoperatively. There were no toxic reactions, implants extruded, or wound infections. Histologic examination of the implant-soft-tissue interfaces revealed a transient inflammatory response without foreign body reaction. The disks were resorbed over time in direct proportion to their macropore content (surface areas) in all groups except for those disks placed directly onto the surface of the calvarium below the periosteum. In this group, numerous foci of bone formed at the skull-implant interface, with variable replacement of the deep surface of these implants by bone. Implant replacement by bone is postulated to occur through a combination of implant resorption coupled with osteoconduction. Based on these properties, hydroxyapatite cement may prove useful when applied to the reconstruction of non-stress-bearing skeletal tissue.
羟基磷灰石骨水泥是一种独特的磷酸钙制剂，可在术中塑形，并在体内固化为微孔羟基磷灰石组成的植入物。通过将由这种材料制成的圆盘植入9只猫的头部，评估了对这种骨水泥的组织学反应。制备了三组12个羟基磷灰石骨水泥圆盘，其大孔体积分别为0%、10%和20%。将圆盘分别皮下、肌肉内、颅骨骨膜上方以及直接植入颅骨表面。每个组织平面都有每种大孔百分比的样本，术后9个月内处死动物。未出现毒性反应、植入物挤出或伤口感染。对植入物-软组织界面的组织学检查显示有短暂的炎症反应，无异物反应。除了直接置于颅骨骨膜下表面的圆盘外，所有组中的圆盘均随时间按其大孔含量（表面积）的比例被吸收。在该组中，颅骨-植入物界面形成了许多骨灶，这些植入物的深表面被骨不同程度地替代。推测植入物被骨替代是通过植入物吸收与骨传导相结合的方式发生的。基于这些特性，羟基磷灰石骨水泥在应用于非承重骨骼组织的重建时可能会被证明是有用的。
