fibula的复数形式怎么写？

fibula的音标：fibula的英式发音音标为：['fɪbjələ]fibula的美式发音音标为：['fɪbjələ]...

n.腓骨，（古希腊、罗马）搭扣，扣针...

He stumbled when playing on the field and injured his fibula.他打球的时候摔了一跤,腓骨骨折了.There is also tender pain in the upper section of the fibula.腓骨上段也有压痛.The incidence of severe open fractures of tibia and fibula is increasing...