Gejo Ryuichi, Morita Yuji, Matsushita Isao, Sugimori Kazuhito, Kimura Tomoatsu
Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, 2630 Sugitani Toyama-city, Toyama, 930-0194, Japan.
Clin Orthop Relat Res. 2008 Apr;466(4):946-51. doi: 10.1007/s11999-008-0154-2. Epub 2008 Feb 9.
Balancing of the joint gap in extension and flexion is a prerequisite for success of a total knee arthroplasty. The joint gap is influenced by patellar position. We therefore hypothesized the state of the knee extensor mechanism (including the patellar tendon) would influence the joint gap. In 20 knees undergoing posterior-stabilized type total knee arthroplasties, we measured the joint gap and the patellar tendon strain from 0 degrees to 135 degrees flexion with the femoral component in position. When the patella was reduced, the joint gap was decreased at 90 degrees and 135 degrees (by 1.9 mm and 5.5 mm, respectively) compared with the gap with the patella everted. The patellar tendon strain increased with knee flexion. Patellar tendon strain at 90 degrees flexion correlated with the joint gap difference with the patella in everted and reduced positions. This suggests that in addition to the collateral ligaments, the knee extensor mechanism may have an influence on the joint gap. Therefore, accounting for extensor mechanism tightness may be important in achieving the optimal joint gap balance during total knee arthroplasty.
Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
伸直和屈曲时关节间隙的平衡是全膝关节置换术成功的前提条件。关节间隙受髌骨位置的影响。因此，我们假设膝关节伸肌机制（包括髌腱）的状态会影响关节间隙。在20例行后稳定型全膝关节置换术的膝关节中，我们在股骨假体就位的情况下，测量了从0度到135度屈曲时的关节间隙和髌腱应变。当髌骨复位时，与髌骨外翻时相比，在90度和135度时关节间隙减小（分别减小1.9毫米和5.5毫米）。髌腱应变随膝关节屈曲而增加。90度屈曲时的髌腱应变与髌骨外翻和复位位置时的关节间隙差异相关。这表明除了侧副韧带外，膝关节伸肌机制可能对关节间隙有影响。因此，在全膝关节置换术中考虑伸肌机制的紧张度对于实现最佳关节间隙平衡可能很重要。
IV级，治疗性研究。有关证据水平的完整描述，请参见作者指南。
