What type of arthritis is a noninflammatory disorder of synovial joints?

Osteoarthritis is the correct answer as it is characterized as a noninflammatory disorder affecting synovial joints. This degenerative joint disease results from the breakdown of cartilage, leading to pain and stiffness, particularly with movement. Unlike inflammatory types of arthritis, such as rheumatoid arthritis, osteoarthritis does not involve the immune system attacking the joint tissues and does not typically lead to swelling or systemic symptoms.

The other options do not represent arthritis or joint disorders. Osteomyelitis refers to an infection in the bone, which is an entirely different condition. A subdural hematoma is a type of bleeding that occurs on the surface of the brain, unrelated to joint disorders. Similarly, a comminuted fracture describes a condition where a bone is broken into multiple pieces, which pertains to bone trauma rather than a joint disease. Thus, osteoarthritis stands out as the only noninflammatory arthritic condition among the choices provided.