Moroni Antonio, Pegreffi Francesco, Cadossi Matteo, Hoang-Kim Amy, Lio Valentino, Giannini Sandro
Istituti Ortopedici Rizzoli, Bologna University, Italy.
Expert Rev Med Devices. 2005 Jul;2(4):465-71. doi: 10.1586/17434440.2.4.465.
The aim of this review is to report on studies of hydroxyapatite-coated external fixation pins as a solution to enhance pin fixation. In a highly loaded animal study, three tapered pin types were compared: Type A uncoated, Type B coated with hydroxyapatite and Type C coated with titanium. There was a 13-fold increase in the extraction torque of Type B pins compared with Type A, and a twofold increase compared with Type C pins. Extraction torque was significantly lower compared with the corresponding insertion torque in both Types A (p < 0.001) and C (p = 0.003). Conversely, with the hydroxyapatite-coated pins there was no difference between extraction and insertion torque. In a clinical study of 76 external fixation pins in 19 patients treated with hemicallotasis for osteoarthritis on the medial side of the knee, pin insertion and extraction torque forces were measured. The patients were randomized to be treated with either standard tapered pins or tapered pins coated with hydroxyapatite. Extraction torque of the hydroxyapatite-coated pins was higher than the extraction torque of the standard pins in both cancellous and cortical bone (p < 0.005). In a prospective, randomized clinical study of osteoporotic wrist fractures, extraction torque of the coated pins was higher than with standard pins (p < 0.0001). These studies demonstrate that with the use of hydroxyapatite-coated pins, no deterioration of pin fixation occurs, and that there is no significant pin loosening and infection, regardless of bone type and loading conditions.
本综述的目的是报告关于羟基磷灰石涂层外固定针作为增强针固定解决方案的研究。在一项高负荷动物研究中，比较了三种锥形针类型：A型未涂层、B型涂有羟基磷灰石、C型涂有钛。与A型针相比，B型针的拔出扭矩增加了13倍，与C型针相比增加了两倍。A型（p < 0.001）和C型（p = 0.003）针的拔出扭矩与相应的插入扭矩相比均显著降低。相反，对于羟基磷灰石涂层针，拔出扭矩和插入扭矩之间没有差异。在一项对19例因膝关节内侧骨关节炎接受半骨骺牵伸治疗的患者的76根外固定针的临床研究中，测量了针的插入和拔出扭矩力。患者被随机分为接受标准锥形针或涂有羟基磷灰石的锥形针治疗。在松质骨和皮质骨中，羟基磷灰石涂层针的拔出扭矩均高于标准针（p < 0.005）。在一项关于骨质疏松性腕部骨折的前瞻性随机临床研究中，涂层针的拔出扭矩高于标准针（p < 0.0001）。这些研究表明，使用羟基磷灰石涂层针时，针固定不会恶化，并且无论骨类型和负荷条件如何，均不会出现明显的针松动和感染。
