Abu al-Zinad (may Allah have mercy on him) narrates from the jurists of Madinah that there is retaliation for every fracture and wound, except that there is no retaliation for a head wound (ma'mumah), a belly wound (ja'ifah), or a wound that destroys (a limb); for these there is blood money. And Isa (may Allah have mercy on him) says in his narration: They used to say: The thigh is among the (injuries) that destroy.
This has been narrated from the Prophet (peace and blessings be upon him) with chains the like of which are not established.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنايات / 16099