It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that he performed ablution while his hand was bandaged, so he wiped over the bandages and washed the remaining limbs. This narration from Ibn Umar (may Allah be pleased with them both) is sahih (authentic). (b) Imam al-Shafi'i (may Allah have mercy on him) said: A hadith has been narrated from Sayyiduna Ali (may Allah be pleased with him) that one of his forearm bones was broken, and the Prophet (peace and blessings be upon him) ordered him to "wipe over the splints". The Imam (may Allah have mercy on him) said: If I knew its chain to be sahih, I would give a ruling according to it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 1081