What physical structure does skeletal traction directly engage with during treatment?

Skeletal traction directly engages with bone because it involves applying a mechanical force to a skeletal structure through devices like pins, screws, or wires that are inserted into the bone. This method aims to realign fractured bones or relieve pressure on bones and joints by using weights and pulleys. By anchoring the traction devices to the bone, the treatment can effectively create tension that helps stabilize the skeletal system, thereby promoting proper healing and alignment of fractures.

While muscles, skin, and nerves are involved in the overall context of skeletal traction, the direct engagement occurs solely at the bony structure itself, making it the most relevant choice in the context of this treatment modality.