Kinematic alignment of current TKA implants does not restore the native trochlear anatomy
Kinematic alignment of current TKA implants does not restore the native trochlear anatomy
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DOI：
10.1016/j.otsr.2018.05.010
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发表时间：
2018-11-01
影响因子：
2.3
通讯作者：
Harris, Simon
中科院分区：
文献类型：
--
作者：
Riviere, Charles;Dhaif, Fatima;Harris, Simon
引言：保留髌股结构解剖，从而产生生理性髌股运动学，可以预防髌股并发症，改善运动学对齐TKA （KA TKA）后的临床效果。我们的研究目的是1)比较天然滑车和假体滑车（计划的或植入的），2)评估植入更大的假体(R)股骨假体大小与近侧滑车突面高度（凸缘面积）相匹配的安全性，以减少假体KA滑车产生的天然关节面填充。方法：采用常规KA技术（第1组，36个模型，计划KA - TKA）或替代KA技术（AT - KA - TKA），以匹配近端（翼缘区）外侧关节突高度（10个模型，计划AT - KA - TKA），将假体(R)股骨假体三维模型在健康膝关节的三维骨-软骨模型上进行虚拟运动学对齐。此外，13个术后骨植入物（KA Persona (R)）模型与术前骨软骨模型（2组植入KA TKA）共同注册到相同的坐标几何。使用内部分析软件比较各组的原生和假体滑车关节面和中外侧种植体悬垂。结果：与天然滑车相比，计划和实施的假滑车相似且外翻导向（分别为6.1和8.5），基本上近端填充不足。AT KA tka显示高的天然滑车表面填充率（70%，90%和100%用于外侧小关节面，沟，内侧小关节面）和中外侧种植体悬垂（60%）。传统KA - tka股骨前切口与股骨前切口齐平，无填充物。结论：我们发现，无论是计划的还是植入的股骨假体，KA假体(R)滑车与天然滑车解剖结构相比，更外翻导向和填充不足。此外，通过增加股骨假体的大小来恢复外侧滑车小面高度会产生较高的滑车填充率和内外侧假体悬垂率。虽然用KA - TKA修复原生滑车是不可能的，但其临床影响很低，特别是对PF并发症。在目前的实践中，最好缩小种植体的尺寸，即使它不能恢复原有的解剖结构。使用现有种植体进行KA tka需要更长时间的随访，并且开发新的，更解剖的，专门为KA技术设计的种植体的争论现在开始了。(C) 2018 Elsevier Masson SAS。版权所有。
Introduction: Preserving constitutional patellofemoral anatomy, and thus producing physiological patellofemoral kinematics, could prevent patellofemoral complications and improve clinical outcomes after kinematically aligned TKA (KA TKA). Our study aims 1) to compare the native and prosthetic trochleae (planned or implanted), and 2) to estimate the safety of implanting a larger Persona (R) femoral component size matching the proximal lateral trochlea facet height (flange area) in order to reduce the native articular surfaces understuffing generated by the prosthetic KA trochlea.Methods: Persona (R) femoral component 3D model was virtually kinematically aligned on 3D bone-cartilage models of healthy knees by using a conventional KA technique (group 1, 36 models, planned KA TKA) or an alternative KA technique (AT KA TKA) aiming to match the proximal (flange area) lateral facet height (10 models, planned AT KA TKA). Also, 13 postoperative bone-implant (KA Persona (R)) models were co-registered to the same coordinate geometry as their preoperative bone-cartilage models (group 2 implanted KA TKA). In-house analysis software was used to compare native and prosthetic trochlea articular surfaces and medio-lateral implant overhangs for every group.Results: The planned and performed prosthetic trochleae were similar and valgus oriented (6.1 and 8.5, respectively), substantially proximally understuffed compared to the native trochlea. The AT KA TKAs shows a high rate of native trochlea surface overstuffing (70%, 90%, and 100% for lateral facet, groove, medial facet) and mediolateral implant overhang (60%). There was no overstuffing with conventional KA TKAs having their anterior femoral cut flush.Conclusion: We found that with both the planned and implanted femoral components, the KA Persona (R) trochlea was more valgus oriented and understuffed compared to the native trochlear anatomy. In addition, restoring the lateral trochlea facet height by increasing the femoral component size generated a high rate of trochlea overstuffing and mediolateral implant overhang. While restoring a native trochlea with KA TKA is not possible, the clinical impact of this is low, especially on PF complications. In current practice it is better to undersize the implants even if it does not restore the native anatomy. Longer follow-up is needed for KA TKAs performed with current implant, and the debate of developing new, more anatomic, implants specifically designed for KA technique is now opened. (C) 2018 Elsevier Masson SAS. All rights reserved.