Objective: To summarize the progress of larger flexion gap than extension gap in total knee arthro-plasty (TKA).
Methods: The domestic and foreign related literature about larger flexion gap than extension gap in TKA, and its impact factors, biomechanical and kinematic features, and clinical results were summarized.
Results: During TKA, to adjust the relations of flexion gap and extension gap is one of the key factors of successful operation. The biomechanical, kinematic, and clinical researches show that properly larger flexion gap than extension gap can improve both the postoperative knee range of motion and the satisfaction of patients, but does not affect the stability of the knee joint. However, there are also contrary findings. So adjustment of flexion gap and extension gap during TKA is still in dispute.
Conclusion: Larger flexion gap than extension gap in TKA is a new joint space theory, and long-term clinical efficacy, operation skills, and related complications still need further study.
目的: 对人工全膝关节置换术（total knee arthroplasty，TKA）中屈曲间隙大于伸直间隙的相关研究进展进行综述。.
方法: 广泛查阅国内外有关膝关节屈伸间隙影响因素，以及 TKA 术中增加屈曲间隙后膝关节生物力学及运动学改变特点、临床效果等方面的研究文献，并进行总结分析。.
结果: TKA 术中调整屈伸间隙关系是影响手术成败关键因素之一。目前大量生物力学、运动学及临床研究显示，TKA 术中屈曲间隙适当大于伸直间隙可以改善术后膝关节活动度、提高患者满意度，同时不影响膝关节稳定性；但也有研究结果与之相反。因此，TKA 术中对于屈伸间隙的调整尚存在争议。.
结论: TKA 术中调整屈曲间隙至适当大于伸直间隙是一种新的关节间隙理论，其中远期临床效果、术中操作技巧以及相关并发症有待后续临床实践探索。.
Keywords: Total knee arthroplasty; extension gap; flexion gap; knee stability; range of motion.