Division of Orthopaedic Surgery, Department of Surgery, Schulich School of Medicine and Dentistry, Western University, London Health Sciences Centre, University Hospital, London, Ontario, Canada.
Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada; Surgical Innovation Program, Lawson Health Research Institute, London, Ontario, Canada.
J Arthroplasty. 2018 Jan;33(1):268-272. doi: 10.1016/j.arth.2017.08.027. Epub 2017 Aug 31.
Trunnionosis at the modular head-neck taper interface in metal-on-polyethylene total hip arthroplasty (MoP THA) has been shown to occur, and represents a potential mode of MoP THA failure. The purpose of the present investigation is to elucidate differences in fretting and corrosion at the head-neck taper interface of prostheses retrieved from bipolar hemiarthroplasty (BH) and MoP THA.
A retrieval analysis of BH and MoP THA prostheses featuring a single taper design from a single manufacturer and in vivo for a minimum 2 years was performed. Fifteen femoral heads of 28-mm diameter and corresponding femoral stems retrieved from BH were compared with MoP THA implants matched based on time in vivo and head length (28 mm, -3 mm to 28 mm, +8 mm). Fretting and corrosion damage scoring was completed under stereomicroscopic visualization.
Femoral head bore tapers retrieved from BH exhibited decreased overall fretting (P = .02), when compared to those retrieved from MoP THA. Total corrosion scores for all retrieved implants were positively correlated with implantation time (ρ = 0.54, P < .02).
Femoral heads retrieved from BH exhibit decreased fretting damage compared to those retrieved from MoP THA. The added articulation in BH implants may decrease torque produced at the head-neck taper junction, thereby decreasing fretting. Increased fretting damage in implants from MoP THA is not associated with increased corrosion in 28-mm heads of this taper design. The longer a BH or MoP THA prosthesis is implanted, the greater the risk of damage due to corrosion.
金属对聚乙烯全髋关节置换术（MoP THA）中在模块化头-颈锥度界面处的臼杯变形已被证实会发生，这代表 MoP THA 失效的一种潜在模式。本研究的目的是阐明从双极半髋关节置换术（BH）和 MoP THA 中取出的假体在头-颈锥度界面处的微动和腐蚀的差异。
对来自单一制造商的具有单一锥度设计的 BH 和 MoP THA 假体进行了回顾性分析，假体的体内使用时间至少为 2 年。对从 BH 中取出的 15 个直径为 28mm 的股骨头和相应的股骨柄进行了研究，并与 MoP THA 植入物进行了匹配，匹配的依据是体内时间和头长（28mm、-3mm 到 28mm、+8mm）。在立体显微镜可视化下完成了微动和腐蚀损伤评分。
与从 MoP THA 中取出的假体相比，从 BH 中取出的股骨头内锥的整体微动（P =.02）减少。所有取出假体的总腐蚀评分与植入时间呈正相关（ρ = 0.54，P <.02）。
与从 MoP THA 中取出的假体相比，从 BH 中取出的股骨头的微动损伤减少。BH 植入物增加的关节活动度可能会降低头-颈锥度交界处产生的扭矩，从而减少微动。MoP THA 中植入物的微动损伤增加与这种锥度设计的 28mm 头的腐蚀增加无关。BH 或 MoP THA 假体植入的时间越长，由于腐蚀导致损坏的风险就越大。
