The patella is an important functional component of the knee extension mechanism. It accounts for 13 to 30% of the knee extensors' moment arm. Functional deficits owing to patellectomy include decreased knee extension power, extension lag, instability, chronic effusion, decreased stance phase flexion, alteration of the path of instant flexion centers and decreased flexion range.
髌骨是膝关节伸展机制的重要功能组成部分。它占膝关节伸肌力矩臂的13%至30%。髌骨切除导致的功能缺陷包括膝关节伸展力量减弱、伸展滞后、不稳定、慢性积液、站立期屈曲减少、即时屈曲中心路径改变以及屈曲范围减小。
