Łapaj Łukasz, Rozwalka Justyna
Department of General Orthopaedics, Musculoskeletal Oncology and Trauma Surgery, Poznan University of Medical Sciences, Ortopedyczno-Rehabilitacyjny Szpital Kliniczny im. Degi, Poznań, Poland.
Research Network Łukasiewicz, Metal Forming Institute, Poznan, Poland.
J Biomed Mater Res B Appl Biomater. 2020 May;108(4):1251-1261. doi: 10.1002/jbm.b.34473. Epub 2019 Aug 31.
Titanium nitride (TiN) coatings are used in joint arthroplasty to minimize wear and reduce the allergenic potential of metal implants, yet little is known about their performance in knee arthroplasty. This retrieval study examined TiN coated knee replacements to verify in vivo wear and degradation of the coating.
This study included total and unicompartmental mobile bearing knee replacements retrieved from five patients (eight components) after 13-21 months due to aseptic loosening or infection. Implants were examined using scanning (SEM) and optical microscopy, surface damage was assessed using a semiquantitative scoring system, adhesion was determined using indentation technique testing, surface roughness was measured using contact profilometry.
Although good coating adhesion and no gross failure were observed on all retrievals, coating wear and roughening were evident on tibial bearing surfaces. Multiple microscopic defects (pinholes, craters, titanium droplets) were observed on all samples in SEM studies. Microscopic wear scars indicated that particulate defects significantly contributed to coating wear, acting as third bodies.
TiN coatings of knee replacements undergo wear and degradation related to presence of third bodies and microscopic defects on their surface. Since coating integrity may be compromised in vivo, such implants should be used with caution in metal sensitive patients.
氮化钛（TiN）涂层用于关节置换术中，以减少磨损并降低金属植入物的致敏可能性，但人们对其在膝关节置换术中的性能了解甚少。这项回收研究检查了TiN涂层膝关节置换物，以验证涂层在体内的磨损和降解情况。
本研究纳入了因无菌性松动或感染在13 - 21个月后从5名患者（8个组件）中回收的全膝关节和单髁活动轴承膝关节置换物。使用扫描电子显微镜（SEM）和光学显微镜对植入物进行检查，使用半定量评分系统评估表面损伤，使用压痕技术测试确定附着力，使用接触轮廓仪测量表面粗糙度。
尽管在所有回收的样本中均观察到良好的涂层附着力且无明显失效，但在胫骨承重表面涂层磨损和粗糙度增加明显。在SEM研究中，所有样本上均观察到多个微观缺陷（针孔、凹坑、钛滴）。微观磨损痕迹表明，颗粒缺陷作为第三体对涂层磨损有显著影响。
膝关节置换物的TiN涂层会因第三体的存在及其表面的微观缺陷而发生磨损和降解。由于涂层完整性在体内可能会受到损害，因此在对金属敏感的患者中应谨慎使用此类植入物。
