Dimitriou Dimitris, Tsai Tsung-Yuan, Park Kwan Kyu, Hosseini Ali, Kwon Young-Min, Rubash Harry E, Li Guoan
Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA.
Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA; Department of Orthopedic Surgery, Yonsei University, College of Medicine, Seoul, South Korea.
J Biomech. 2016 Jun 14;49(9):1891-1898. doi: 10.1016/j.jbiomech.2016.04.033. Epub 2016 May 3.
An equal knee joint height during flexion and extension is of critical importance in optimizing soft-tissue balancing following total knee arthroplasty (TKA). However, there is a paucity of data regarding the in-vivo knee joint height behavior. This study evaluated in-vivo heights and anterior-posterior (AP) translations of the medial and lateral femoral condyles before and after a cruciate-retaining (CR)-TKA using two flexion axes: surgical transepicondylar axis (sTEA) and geometric center axis (GCA). Eleven osteoarthritis (OA) knee patients were studied during a weight-bearing single leg lunge, using a validated dual fluoroscopic imaging system (DFIS) based tracking technique. Eight healthy subjects were recruited as controls. The results demonstrated that following TKA, the medial and lateral femoral condyle heights were not equal at mid-flexion (15-45°, medial condyle lower then lateral by 2.4mm at least, p<0.01), although the knees were well-balanced at 0° and 90°. While the femoral condyle heights increased from the pre-operative values (>2mm increase on average, p<0.05), they were similar to the intact knees except that the medial sTEA was lower than the intact medial condyle between 0° and 90°. At deep flexion (>90°), both condyles were significantly higher (>2mm, p<0.01) than the healthy knees. Anterior femoral translation of the TKA knee was more pronounce at mid-flexion, whereas limited posterior translation was found at deep flexion. These data suggest that a well-balanced knee intra-operatively might not necessarily result in mid-flexion and deep flexion balance during functional weight-bearing motion, implying mid-flexion instability and deep flexion tightness of the knee.
在全膝关节置换术（TKA）后优化软组织平衡方面，屈伸过程中膝关节高度相等至关重要。然而，关于体内膝关节高度行为的数据却很匮乏。本研究使用两个屈曲轴：手术经髁轴（sTEA）和几何中心轴（GCA），评估了保留交叉韧带（CR）-TKA前后股骨内外侧髁的体内高度及前后（AP）平移情况。使用经过验证的基于双荧光透视成像系统（DFIS）的跟踪技术，对11例骨关节炎（OA）膝关节患者在负重单腿弓步动作时进行了研究。招募了8名健康受试者作为对照。结果表明，TKA后，在屈膝中期（15 - 45°，内侧髁至少比外侧髁低2.4mm，p<0.01）时，股骨内外侧髁高度不相等，尽管在0°和90°时膝关节平衡良好。虽然股骨髁高度较术前值有所增加（平均增加>2mm，p<0.05），但除了在0°至90°之间内侧sTEA低于完整内侧髁外，它们与完整膝关节相似。在深度屈膝（>90°）时，两个髁均显著高于健康膝关节（>2mm，p<0.01）。TKA膝关节在屈膝中期的股骨向前平移更明显，而在深度屈膝时发现向后平移受限。这些数据表明，术中平衡良好的膝关节在功能性负重运动中不一定能实现屈膝中期和深度屈膝时的平衡，这意味着膝关节存在屈膝中期不稳定和深度屈膝时过紧的情况。
