Our literature review indicates that our patient the youngest one diagnosed with chondroblastoma in the talus.

本病例是一位十八个月大男，病灶位于左踝，比较罕见，手术前诊断也比较困难，故加以分析讨论。

The os trigonum is an accessory bone of the foot, locates at the posterolateral tubercle of the talus, and occures in about 7% of population.

摘要附三角位于距侧节，是脚部的附属一，出现于百分七的正常人中。