Overgaard S, Lind M, Rahbek O, Bünger C, Søballe K
Department of Orthopaedics, University Hospital of Aarhus, Denmark.
Acta Orthop Scand. 1997 Aug;68(4):337-43. doi: 10.3109/17453679708996173.
We inserted, in 8 dogs, implants with either porous-coated or grit-blasted titanium surface and coated with hydroxyapatite (HA) into trabecular bone in the proximal humerus, using a 1 mm gap model. After 25 weeks, push-out tests showed that energy absorption for porous-coated implants was twice that of grit-blasted implants, whereas shear stiffness was reduced by one fifth, indicating a stronger fixation of porous-coated implants. Macroscopically, all grit-blasted implants had delamination of the HA coating, whereas porous implants failed mostly at the HA-tissue interface. Porous-coated implants had 47% bone ingrowth and grit-blasted implants 70% (p = 0.02), however, no difference in absolute surface area was found. Part of the HA coating was resorbed during the implantation period as regards volume and thickness. HA coverage was more reduced on porous-coated than on grit-blasted implants (p = 0.01). No foreign-body reaction or osteolysis was seen. An important finding was that one fifth of the surface with complete resorption of HA coating was replaced by newly formed bone.
我们在8只狗的肱骨近端小梁骨中，采用1毫米间隙模型植入了表面为多孔涂层或喷砂处理的钛且涂有羟基磷灰石（HA）的植入物。25周后，推出试验表明，多孔涂层植入物的能量吸收是喷砂处理植入物的两倍，而剪切刚度降低了五分之一，这表明多孔涂层植入物的固定更强。宏观上，所有喷砂处理的植入物的HA涂层都有分层，而多孔植入物大多在HA与组织的界面处失效。多孔涂层植入物的骨长入率为47%，喷砂处理植入物为70%（p = 0.02），然而，在绝对表面积上未发现差异。在植入期间，HA涂层的部分体积和厚度被吸收。多孔涂层植入物的HA覆盖率比喷砂处理植入物降低得更多（p = 0.01）。未观察到异物反应或骨溶解。一个重要发现是，HA涂层完全吸收的表面的五分之一被新形成的骨取代。
