Caja V L, Moroni A
Third Department of Orthopaedic Surgery, Rizzoli Orthopaedic Institute, Bologna, Italy.
Clin Orthop Relat Res. 1996 Apr(325):269-75. doi: 10.1097/00003086-199604000-00033.
A sheep model was developed for the implantation of 84 bicylindrical stainless steel external fixation pins. One-half of the pins were coated with hydroxyapatite, and the rest remained uncoated. A set of 6 pins with the same coating was implanted in the lateral side of the left tibias of 14 sheep, the final insertion torque was measured, and a monolateral external fixator was assembled on the pins. The medial tibial middiaphysis then was exposed and a 5-mm resection osteotomy was done. Sheep were euthanized 6 weeks after surgery, radiographs were taken, and the initial extraction torque was measured on 4 pins from each sheep. Undecalcified sectioning and histologic and histomorphometric analyses were done on the remaining 2 pins. Radiographic pin tract rarefaction was significantly lower in the hydroxyapatite coated pins compared with the uncoated pins. Group average insertion torque was 960 +/- 959 Nmm in the hydroxyapatite coated pins and 709 +/- 585 Nmm in the uncoated pins. Group average initial extraction torque was 1485 +/- 1308 Nmm and 298 +/- 373 Nmm, respectively. Bone pin contact was 85.7% +/- 8.9% and 50.3% +/- 20.4%, respectively, in hydroxyapatite coated and uncoated pins. Bone between the threads was 95.6% +/- 5.7% and 80% +/- 8.7%, respectively, in hydroxyapatite coated and uncoated pins. Hydroxyapatite coating was effective for improving the bone-to-pin interface.
建立了一个用于植入84根双圆柱形不锈钢外固定针的绵羊模型。其中一半的针涂有羟基磷灰石，其余的保持未涂层状态。将一组6根具有相同涂层的针植入14只绵羊左胫骨的外侧，测量最终插入扭矩，并在这些针上组装单侧外固定器。然后暴露胫骨内侧中骨干并进行5毫米的截骨术。术后6周对绵羊实施安乐死，拍摄X光片，并测量每只绵羊4根针的初始拔出扭矩。对其余2根针进行未脱钙切片以及组织学和组织形态计量学分析。与未涂层的针相比，羟基磷灰石涂层针的X光片显示针道稀疏明显更低。羟基磷灰石涂层针组的平均插入扭矩为960±959牛毫米，未涂层针组为709±585牛毫米。两组的平均初始拔出扭矩分别为1485±1308牛毫米和298±373牛毫米。羟基磷灰石涂层针和未涂层针的骨针接触率分别为85.7%±8.9%和50.3%±20.4%。羟基磷灰石涂层针和未涂层针螺纹间的骨组织分别为95.6%±5.7%和80%±8.7%。羟基磷灰石涂层对于改善骨针界面是有效的。
