Abdel Matthew P, Gesell Mark W, Hoedt Christen W, Meyers Kathleen N, Wright Timothy M, Haas Steven B
Adult Reconstruction and Joint Replacement Division, Hospital for Special Surgery, 535 East 70th Street, New York, NY, 10021, USA,
Clin Orthop Relat Res. 2014 Aug;472(8):2477-82. doi: 10.1007/s11999-014-3621-y. Epub 2014 Apr 15.
Backside damage of the polyethylene in TKA is a potential source of debris. The location of the tibial post in posterior-stabilized implants may influence micromotion, and thus affect backside damage, as may surface roughness.
We used implant retrieval analysis to (1) examine if there were differences in backside damage among three modern posterior-stabilized implants attributable to variable surface roughness; (2) determine if the location of damage on the tibial post affected the pattern of backside damage; and (3) determine if demographics influenced backside damage.
We identified 403 posterior-stabilized tibial retrieved inserts (147 NexGen(®), 152 Optetrak(®), 104 Genesis(®) II). The damage on the surfaces of the tibial posts was previously graded. The backside of the inserts (divided into quadrants) were scored for evidence of damage. The total quadrant damage was compared for each implant group, the relationship between post face damage and location of damage on the backside was determined for each implant group, and total backside damage was compared among the three implant groups.
No correlation was found between the location of damage on the post and location of damage on the backside of the implant for any of the three groups. The Genesis(®) II polyethylene implants, which articulate with a highly polished tibial tray, showed a significantly lower total backside damage score (p < 0.01) when compared with the other two implant groups. The Genesis(®) II and Optetrak(®) showed significantly more damage in the posterior quadrants of the implants (p < 0.01) when compared with the anterior quadrants. A linear regression analysis revealed that lower tibial tray surface roughness was correlated with decreased damage.
An implant design with a highly polished tibial tray was associated with decreased backside damage. However, tibial post design and location did not influence the location of backside damage.
Our study showed that a highly polished tibial tray was associated with decreased damage to the backside of polyethylene inserts independent of post design and location. These findings should be taken into consideration when new generations of implants are designed.
全膝关节置换术中聚乙烯的后侧磨损是碎屑的潜在来源。后稳定型植入物中胫骨柱的位置可能会影响微动，进而影响后侧磨损，表面粗糙度也可能有同样的影响。
我们采用植入物取出分析来（1）检查三种现代后稳定型植入物因表面粗糙度不同，后侧磨损是否存在差异；（2）确定胫骨柱上的磨损位置是否会影响后侧磨损模式；（3）确定人口统计学因素是否会影响后侧磨损。
我们鉴定出403个后稳定型胫骨取出的衬垫（147个NexGen®、152个Optetrak®、104个Genesis®II）。胫骨柱表面的磨损之前已进行分级。对衬垫的后侧（分为四个象限）进行评分以确定磨损迹象。比较每个植入物组的总象限磨损，确定每个植入物组中柱面磨损与后侧磨损位置之间的关系，并比较三个植入物组之间的后侧总磨损。
对于三组中的任何一组，均未发现柱上磨损位置与植入物后侧磨损位置之间存在相关性。与高度抛光的胫骨托相匹配的Genesis®II聚乙烯植入物，与其他两组植入物相比，后侧总磨损评分显著更低（p<0.01）。与前侧象限相比，Genesis®II和Optetrak®在植入物后侧象限的磨损明显更多（p<0.01）。线性回归分析显示，较低的胫骨托表面粗糙度与磨损减少相关。
具有高度抛光胫骨托的植入物设计与后侧磨损减少相关。然而，胫骨柱设计和位置并未影响后侧磨损的位置。
我们的研究表明，高度抛光的胫骨托与聚乙烯衬垫后侧磨损减少相关，与柱设计和位置无关。在设计新一代植入物时应考虑这些发现。
