What is a plaster cast used for?

A plaster cast serves a crucial role in the management of fractures by providing protection and immobilization to the injured area. When a bone is fractured, it needs to remain still and in the correct position to heal properly. The rigidity of the plaster cast restricts movement, minimizing the risk of further injury and allowing the bone to mend in the right alignment. This supportive structure also protects the fracture site from external forces, such as bumps or pressure that could disrupt the healing process.

While aligning fractured bones is important, that process typically occurs during the initial treatment before the application of the cast. An open reduction involves a surgical procedure to realign bones, while surgical fusion pertains to permanent joining of bones, which does not involve the use of a plaster cast in the same way. Therefore, using a plaster cast is primarily about immobilization and protection, which is why this answer stands out as the correct choice.