Yī / shēng / jiě / shì / shuō / pián / xié / shì / yì / zhǒng / xiān / tiān / xìng / de / xiōng / kuò / yì / cháng医生解释说,骈胁是一种先天性的胸廓异常。The doctor explained that fused ribs are a congenital abnormality of the chest.