Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Göttingen, Robert-Koch Str. 40, 37075, Göttingen, Germany.
Department of Trauma Surgery, University of Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany.
Arch Orthop Trauma Surg. 2024 Jul;144(7):2955-2965. doi: 10.1007/s00402-024-05394-3. Epub 2024 Jun 7.
The malimplantation of the total knee arthroplasty (TKA) components is one of the main reasons for revision surgery. For determining the correct intraoperative femoral rotation several anatomic rotational axes were described in order to achieve a parallel, balanced flexion gap. In this cadaveric study prevalent used rotational femoral axes and a navigated functional rotational axis were compared to the flexion-extension axis defined as the gold standard in rotation for femoral TKA component rotation.
Thirteen body donors with knee osteoarthritis (mean age: 78.85 ± 6.09; eight females and five males) were examined. Rotational computer tomography was performed on their lower extremities pre- and postoperatively. Knee joint arthroplasties were implanted and CT diagnostics were used to compare the preoperatively determined flexion-extension axis (FEA). The FEA is the axis determined by our surgical technique and serves as an internal reference. It was compared to other axes such as (i) the anatomical transepicondylar axis (aTEA), (ii) the surgical transepicondylar axis (sTEA), (iii) the posterior condylar axis (PCA) and (iv) the functional rotation axis (fRA).
Examination of 26 knee joint arthroplasties revealed a significant angular deviation (p < 0.0001) for all axes when the individual axes and FEA were compared. aTEA show mean angular deviation of 5.2° (± 4.5), sTEA was 2.7° (± 2.2), PCA 2.9° (± 2.3) and the deviation of fRA was 4.3° (± 2.7). A tendency towards external rotation was observed for the relative and maximum axis deviations of the aTEA to the FEA, for the sTEA and the fRA. However, the rotation of the posterior condylar axis was towards inwards.
All axes showed a significant angular deviation from the FEA. We conclude that the presented technique achieves comparable results in terms of FEA reconstruction when compared with the use of the known surrogate axes, with certain deviations in terms of outliers in the internal or external rotation.
全膝关节置换术（TKA）假体的不正确植入是翻修手术的主要原因之一。为了确定正确的术中股骨旋转，已经描述了几个解剖学旋转轴，以实现平行、平衡的屈伸间隙。在这项尸体研究中，常用的旋转股骨轴与导航功能旋转轴进行了比较，而屈伸轴被定义为 TKA 组件旋转的金标准。
检查了 13 具患有膝关节骨关节炎的尸体捐赠者（平均年龄：78.85±6.09；8 名女性，5 名男性）。他们的下肢进行了术前和术后旋转计算机断层扫描。膝关节置换术被植入，CT 诊断用于比较术前确定的屈伸轴（FEA）。FEA 是我们手术技术确定的轴，用作内部参考。它与其他轴（i）解剖性髁间轴（aTEA）、（ii）外科性髁间轴（sTEA）、（iii）后髁轴（PCA）和（iv）功能旋转轴（fRA）进行了比较。
检查了 26 个膝关节置换术，当比较各个轴和 FEA 时，所有轴都显示出显著的角度偏差（p<0.0001）。aTEA 的平均角度偏差为 5.2°（±4.5），sTEA 为 2.7°（±2.2），PCA 为 2.9°（±2.3），fRA 的偏差为 4.3°（±2.7）。相对于 FEA，aTEA、sTEA 和 fRA 的相对和最大轴偏差都表现出向外旋转的趋势。然而，后髁轴的旋转是向内的。
所有轴与 FEA 相比都显示出显著的角度偏差。我们的结论是，与使用已知的替代轴相比，所提出的技术在 FEA 重建方面可以达到类似的结果，但是在内部或外部旋转的离群值方面存在一定的偏差。
