**Question:** The most common symptomatic Plica syndrome is

A. Plica Semilunaris
B. Plica Pollicis
C. Plica Pollicis
D. Plica Interpolaris

**Correct Answer:** **D. Plica Interpolaris**

**Core Concept:** Plica syndrome is a condition characterized by inflammation or trauma to one of the serous plicae present in the knee joint. There are three types of plicae:

1. Plica Semilunaris: Located between the medial and lateral menisci, it is the most common plica and rarely causes symptoms.
2. Plica Pollicis: Present in the first carpal tunnel of the wrist, this plica is less common and usually asymptomatic.
3. Plica Interpolaris: Located between the anterior and posterior horns of the lateral meniscus, it is the most common symptomatic plica syndrome. Plica Interpolaris inflammation can lead to pain, swelling, and catching sensations in the knee joint.
4. Plica Semilunaris: Less common, this plica is usually asymptomatic.
5. Plica Pollicis: Present in the wrist, rarely causes symptoms.
6. Plica Interpolaris: Common, often asymptomatic but can present with symptoms in some cases.

**Why the Correct Answer is Right:** Plica Interpolaris is the most common symptomatic plica syndrome among all types. Inflammation or trauma to this plica can cause knee joint pain, swelling, and catching sensations. Its location in the knee joint provides a direct path for irritation to cause symptoms.

**Why Each Wrong Option is Incorrect:**

A. Plica Semilunaris: It is the most common plica but rarely causes symptoms, making it an unsuitable answer.
B. Plica Pollicis: It is less common and usually asymptomatic, making it an unsuitable answer.
C. Plica Pollicis: Similar to option B, it is less common and usually asymptomatic, making it an unsuitable answer.

**Clinical Pearl:** Plica Interpolaris is often asymptomatic but can present with symptoms in some cases. Diagnosis usually involves a thorough clinical examination and imaging studies. Treatment typically involves conservative management such as rest, physical therapy, and anti-inflammatory medications. In severe cases, surgery may be necessary.