**Question:** All of the following statements regarding 'Menisci' is true except:

A. Menisci are avascular cartilage discs located in the knee joint.
B. The menisci play a crucial role in load distribution and joint stability.
C. The menisci are avascular structures, meaning they receive nutrients solely through diffusion from the surrounding synovial fluid.
D. The menisci are primarily composed of muscle tissue.

**Correct Answer:** D. The menisci are primarily composed of muscle tissue.

**Core Concept:** Menisci are fibrocartilaginous structures located in the knee joint, serving crucial roles in load distribution, joint stability, and protection against wear and tear. They are avascular, receiving nutrients through diffusion from the synovial fluid.

**Why the Correct Answer is Right:** Menisci are composed mainly of fibrocartilage, a dense, strong connective tissue containing collagen fibers arranged in a parallel pattern, providing structural integrity and resistance to compression. Although they contain a small amount of smooth muscle cells, the predominant tissue type of the menisci is not muscle tissue, but rather fibrocartilage.

**Why Each Wrong Option is Incorrect:**

A. While menisci are indeed avascular and rely on diffusion for nutrients, the statement "Menisci are avascular cartilage discs" is incorrect because menisci are classified as fibrocartilage, not avascular cartilage.

B. This statement is correct, as menisci play a vital role in load distribution and joint stability, contributing to overall knee joint health and functionality.

C. The statement "The menisci are avascular structures, meaning they receive nutrients solely through diffusion from the surrounding synovial fluid" is accurate, highlighting the unique vascularization pattern of the menisci.

D. This statement is incorrect, as menisci are primarily composed of fibrocartilage, not muscle tissue.

**Clinical Pearl:** Understanding the menisci's tissue composition and function is crucial for interpreting knee joint symptoms and diagnosing meniscal tears or other pathologies. The correct composition of menisci, being fibrocartilage, can help differentiate them from other knee joint structures, such as the articular cartilage or synovial membrane, which are composed of different types of connective tissue.