单髁股骨假体骨水泥固定技术生物力学研究

Biomechanical Study on Cement Fixation of UKA Femoral Prosthesis

摘要: 目的：评估单髁置换术操作过程中涉及到骨水泥涂抹方式、应用时期、温度等因素对骨水泥固定强度的影响。方法：通过推出试验研究骨水泥粘合单髁股骨假体与聚丙烯模具底座的固定强度。在两种实验室温度下(16℃及23℃)使用骨水泥粘结假体与底座，分别在假体面或聚丙烯树脂底座面或两者均涂抹骨水泥；研究使用5℃生理盐水冷却和骨水泥应用时间(包括拉丝期、面团期、硬化期)对固定强度的影响。结果：与单层固定相比，双层固定的推出力并没有提高(P = 0.438)。拉丝期、面团期骨水泥组间推出力差异无统计学意义(P = 0.754)，硬化期应用骨水泥固定强度降低了46.2% (P = 0.001)。较低室温(16℃)下混合骨水泥的推出力比正常室温(23℃)下降低了28.3% (P = 0.015)。而在骨水泥固定后使用5℃冷水给予冷却，推出力降低了34% (P = 0.007)。结论：单髁股骨假体骨水泥的涂抹方式对于固定强度的推出力无明显差异。UKA术中在骨水泥面团期固定操作最合适，温度的降低会降低骨水泥的粘合力。

Abstract: Background: Among the causes of prosthesis loosening in unicompartmental knee arthroplasty (UKA), aseptic loosening is more common. At present, there is less research on the initial fixation strength of bone cement. The purpose of this paper is to evaluate the influence of cement application method, application period, temperature and other factors on the fixation strength of bone cement in the operation of UKA. Methods: The fixed strength of cemented unicompartmental femoral prosthesis and polypropylene mold base was studied by push-out test. Bone cement was applied to the surface of the prosthesis, the surface of the polypropylene resin base, or both at the same time. Objective: To study the effect of 5˚C normal saline cooling and bone cement application time (including wire drawing, dough and hardening stages) on the fixation strength. Results: compared with single-layer fixation, the push-out force of double-layer fixation did not increase (P = 0.438). There was no significant difference in the push-out force between the two groups (P = 0.754). The strength of cement fixation in the hardening stage decreased by 46.2% (P = 0.001). At lower room temperature (16˚C), the pullout force of mixed bone cement was 28.3% lower than that of normal room temperature (23˚C) (P = 0.015). However, when the cement was fixed and cooled by 5˚C cold water, the pushing force decreased by 34% (P = 0.007). Conclusion: There is no significant difference in the push-out force of the fixation strength between the application methods of the femoral prosthesis cement. In UKA, the fixation is the most appropriate in the cement dough stage, and the decrease of temperature will reduce the adhesion of bone cement.