Sudanese Alessandra, Castiello Emanuela, Affatato Saverio
Traumatology and Surgery of Prosthetics and Hip and Knee Reimplantations, Istituto Ortopedico Rizzoli, Bologna, Italy.
Int J Artif Organs. 2013 Jun 25;36(6):421-5. doi: 10.5301/ijao.5000211. Epub 2013 May 8.
From February 2008 to September 2012 we implanted 204 mobile-bearing knee prostheses in 192 patients. All the prostheses were cemented (both femoral and tibial components), and the patella was not replaced. Only one early complication of the implants (1/204 = 0.004%) occurred after a traumatic event as a full 180° rotation of the mobile-bearing polyethylene insert. A 78-year-old woman presented with swelling and severe pain at her right knee. This traumatic event was the only case among our mobile-bearing insert patients. The failed polyethylene inserts were retrieved and studied using a scanning electron microscope (SEM, ZEISS EVO 50 EP, Cambridge, UK) operating at 20 kV. Scratching and pitting were found on the UHMWPE insert perpendicular to the machining tracks for the concave surface. SEM micrographs of the insert showed burnishing on the concave surfaces and longitudinal scratches were clearly detectable and well-marked on the analyzed surfaces. A traumatic, fully rotating, polyethylene insert is rare and our case is the first report describing a traumatic event with a complete 180 degree rotation mobile-bearing in a total knee prosthesis. In the literature few reports discuss clinical outcomes after total knee arthroplasty in patients with Parkinson's disease and they cite mixed results. However, some authors suggest that posterior-stabilized and cruciate-retaining TKA should work well while others prefer cruciate-retaining, condylar constrained kinetics, or hinged devices. Although we did not implant a posterior-stabilized mobile-bearing total knee prosthesis or a constrained prosthesis, we obtained good clinical and radiological results at the 2-year followup.
2008年2月至2012年9月期间，我们为192例患者植入了204个活动平台膝关节假体。所有假体均采用骨水泥固定（股骨和胫骨部件），未置换髌骨。仅1例植入物早期并发症（1/204 = 0.004%）发生于一次外伤事件后，活动平台聚乙烯衬垫发生了整整180°的旋转。一名78岁女性患者右膝出现肿胀和剧痛。这一外伤事件是我们活动平台衬垫患者中的唯一病例。取出失效的聚乙烯衬垫，使用工作电压为20 kV的扫描电子显微镜（SEM，蔡司EVO 50 EP，英国剑桥）进行研究。在超高分子量聚乙烯（UHMWPE）衬垫上，垂直于凹面加工轨迹处发现有刮痕和凹坑。衬垫的扫描电子显微镜图像显示凹面上有抛光现象，在分析表面上可清晰检测到纵向刮痕且痕迹明显。外伤性、完全旋转的聚乙烯衬垫很少见，我们的病例是首例描述全膝关节假体中活动平台发生180度完全旋转外伤事件的报告。文献中很少有关于帕金森病患者全膝关节置换术后临床结果的报道，且结果不一。然而，一些作者认为后稳定型和保留交叉韧带的全膝关节置换术效果良好，而另一些人则更喜欢保留交叉韧带、髁间受限动力学或铰链式装置。虽然我们没有植入后稳定型活动平台全膝关节假体或限制性假体，但在2年随访时我们获得了良好的临床和影像学结果。
