ten Broeke R H M, Alves A, Baumann A, Arts J J C, Geesink R G T
Department of Orthopaedic Surgery, Maastricht University Medical Centre, P O Box 5800, 6202AZ Maastricht, The Netherlands.
J Bone Joint Surg Br. 2011 Jun;93(6):760-8. doi: 10.1302/0301-620X.93B6.24986.
Four uncemented Symax hip stems were extracted at three weeks and nine, 13 and 32 months, respectively, for reasons other than loosening. The reasons for implant removal were infection in two cases, recurrent dislocation in one and acetabular fracture in one. They were analysed to assess the effect and behaviour of an electrochemically deposited, completely resorbable biomimetic BONIT-hydroxyapatite (HA) coating (proximal part) and a DOTIZE surface treatment (distal part) using qualitative histology, quantitative histomorphometry and scanning electron microscopy (SEM). Early and direct bone-implant bonding with signs of active remodelling of bone and the HA coating were demonstrated by histology and SEM. No loose BONIT-HA particles or delamination of the coating were observed, and there was no inflammation or fibrous interposition at the interface. Histomorphometry showed bone-implant contact varying between 26.5% at three weeks and 83.5% at 13 months at the HA-coated implant surface. The bone density in the area of investigation was between 24.6% at three weeks and 41.1% at 32 months. The DOTIZE surface treatment of the distal part of the stem completely prevented tissue and bone apposition in all cases, thereby optimising proximal stress transfer. The overall features of this implant, in terms of geometry and surface texture, suggest a mechanically stable design with a highly active biomimetic coating, resulting in rapid and extensive osseo-integration, exclusively in the metaphyseal part of the stem. Early remodelling of the HA coating does not seem to have a detrimental effect on short-term bone-implant coupling. There were no adverse effects identified from either the BONIT-HA coating or the DOTIZE surface treatment.
分别在术后3周、9个月、13个月和32个月取出了4个非骨水泥型Symax髋关节柄，取出原因均非松动。取出植入物的原因分别为：2例感染、1例复发性脱位和1例髋臼骨折。采用定性组织学、定量组织形态计量学和扫描电子显微镜（SEM）对其进行分析，以评估电化学沉积的、完全可吸收的仿生BONIT-羟基磷灰石（HA）涂层（近端部分）和DOTIZE表面处理（远端部分）的效果和性能。组织学和SEM显示早期骨与植入物直接结合，并有骨和HA涂层活跃重塑的迹象。未观察到BONIT-HA颗粒松动或涂层分层，界面处无炎症或纤维组织插入。组织形态计量学显示，HA涂层植入物表面的骨-植入物接触率在3周时为26.5%，在13个月时为83.5%。研究区域的骨密度在3周时为24.6%，在32个月时为41.1%。柄远端的DOTIZE表面处理在所有病例中均完全阻止了组织和骨的附着，从而优化了近端应力传递。该植入物在几何形状和表面纹理方面的整体特征表明，其设计具有机械稳定性，仿生涂层活性高，仅在柄的干骺端部分实现了快速且广泛的骨整合。HA涂层的早期重塑似乎对短期骨-植入物结合没有不利影响。未发现BONIT-HA涂层或DOTIZE表面处理有不良影响。
