The Nickelodeon presenter took a "chunk out her leg" while preparing for her opening routine on the talent show, Jayne Torvill and Christopher Dean revealed on This Morning.
However, Dean said that he had been impressed by Hamilton's early efforts on the ice, describing her as a "speed demon" who "really attacks it". Hamilton will be partnered by pro skater Colin Ratushniak.
Torvill and Dean said that there had been no other big injury worries other than a few sore ribs.
The sixth series of Dancing On Ice returns this Sunday at 6.30pm on ITV1.