I say, and with God's success: The wiping over the splint is not limited to a specific duration, unlike the wiping over the socks which is limited by a duration; because wiping over the splint and similar items is like washing what is underneath it, and it is not a substitute; because it is conditional upon the inability to wipe the place itself or wash it. Refer to: Sharh al-Wiqayah p. 120, al-Hadiyyah al-‘Alaiyyah pp. 42-43, Nihayat al-Murad p. 400, and God knows best.