Ibn Shihab, Rabi'ah and Ibn Abi Farwah (may Allah have mercy on them) relate from the letter of Sayyiduna Mu'awiyah (may Allah be pleased with him) and the letter of Umar bin Abd al-Aziz (may Allah have mercy on him): "The Prophet (peace and blessings be upon him) did not fix anything for a hand broken by mistake except the bonesetter's fee." If it becomes straight but has crookedness or some defect, its value is assessed, and then the one who broke it pays that as a penalty.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16336