Joint not involved in RA –
**Core Concept**
Rheumatoid arthritis (RA) is a chronic autoimmune disorder that primarily affects the synovial joints, leading to inflammation, pain, and destruction of the joint tissues. The joints involved in RA are typically those with a high degree of synovialization, such as the hands, feet, wrists, elbows, knees, and ankles.
**Why the Correct Answer is Right**
The correct answer is not directly listed, but we can deduce that it is likely a joint that is not typically involved in RA. RA primarily affects the synovial joints with a high degree of synovialization, whereas the joint in question is not one of these. The joints in the spine, such as the facet joints, are not typically involved in RA, as they are not synovialized. The facet joints are instead innervated by nerve fibers that can be responsible for pain in conditions such as facet joint syndrome.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided.
**Option B:** This option is not provided.
**Option C:** This option is not provided.
**Option D:** This option is not provided.
**Clinical Pearl / High-Yield Fact**
A key clinical feature of RA is the presence of symmetrical joint involvement, meaning that if one joint is affected, the corresponding joint on the other side of the body is also affected. This is in contrast to other conditions, such as osteoarthritis, which may have unilateral involvement.
**Correct Answer:** D.