**Core Concept**
Pseudogout, also known as calcium pyrophosphate deposition disease (CPPD), is a type of arthritis characterized by the accumulation of calcium pyrophosphate dihydrate (CPPD) crystals within the joint space. This condition leads to acute inflammatory joint pain, swelling, and limited mobility.

**Why the Correct Answer is Right**
Pseudogout is distinguished from gout by the type of crystals present in the joint fluid. In gout, monosodium urate crystals are found, whereas in pseudogout, calcium pyrophosphate dihydrate (CPPD) crystals are present. The CPPD crystals are thought to be formed due to various factors such as aging, metabolic disorders, or joint trauma. The presence of CPPD crystals triggers an inflammatory response, leading to symptoms similar to those of gout.

**Why Each Wrong Option is Incorrect**
* **Option A:** Pseudogout typically affects older adults and is associated with various metabolic disorders, making this statement incorrect.
* **Option B:** While pseudogout can occur in any joint, it most commonly affects the knee, making this statement incorrect.
* **Option C:** Pseudogout is indeed characterized by the accumulation of calcium pyrophosphate dihydrate (CPPD) crystals in the joint space, making this statement correct.

**Clinical Pearl / High-Yield Fact**
To differentiate pseudogout from gout, it's essential to examine the joint fluid under polarized light microscopy, which will reveal the characteristic CPPD crystals.

**Correct Answer: C. Pseudogout is indeed characterized by the accumulation of calcium pyrophosphate dihydrate (CPPD) crystals in the joint space.**