I say, and with God's success: It is permissible to wipe over the splint in the following cases: First: If washing the broken or wounded member would harm it. Second: If wiping over the site of the surgery would harm it. Third: If there is a fear of causing harm by removing the splint. Refer to: Al-Muhit p. 374, Al-Maraqi p. 135, Al-Durr Al-Mukhtar 1: 187, Al-Bahr 1: 198, and God knows best.