**Core Concept**
Inflammatory arthritis, such as rheumatoid arthritis, is characterized by a chronic inflammatory process that affects the joints. This inflammation leads to various structural and functional changes in the joint, including cartilage and bone destruction.

**Why the Correct Answer is Right**
New bone formation is not typically seen in inflammatory arthritis. In contrast, inflammatory arthritis often leads to bone erosion and joint destruction, resulting in a loss of joint space and function. The chronic inflammation in these conditions can also lead to systemic effects, such as increased erythrocyte sedimentation rate (ESR) and morning stiffness. However, new bone formation is more commonly associated with conditions like osteoarthritis, where cartilage degeneration leads to bone-on-bone contact and subsequent new bone formation as the body attempts to repair the damaged joint.

**Why Each Wrong Option is Incorrect**
**Option A:** Raised ESR is a common finding in inflammatory arthritis, as the chronic inflammation leads to an increase in the production of acute-phase reactants, including C-reactive protein and fibrinogen, which in turn increases the ESR.
**Option B:** Morning stiffness is a characteristic symptom of inflammatory arthritis, resulting from the prolonged inflammation and joint damage that occurs during the night.
**Option C:** Periarticular osteoporosis is a common feature of inflammatory arthritis, as the chronic inflammation leads to an increase in osteoclast activity and a decrease in osteoblast activity, resulting in bone resorption and osteoporosis.

**Clinical Pearl / High-Yield Fact**
Inflammatory arthritis often presents with a combination of symptoms, including joint pain, stiffness, and swelling, as well as systemic effects like fatigue and weight loss. It's essential to consider these symptoms in the context of the patient's medical history and physical examination findings to make an accurate diagnosis.

**✓ Correct Answer: D. New bone formation**