In knee MRI, which finding confirms a meniscal tear?

In knee MRI, which finding confirms a meniscal tear?

• A. Disruption of the meniscal contour with signal extending to the articular surface.
• B. Osteophyte formation
• C. ACL laxity
• D. Joint effusion only

Answer: (A)

A meniscal tear on MRI is confirmed when there is abnormal high-signal within the meniscal substance that extends to an articular surface or when the meniscal contour is disrupted by a cleft. This pattern shows a real tear that communicates with the joint space, indicating a split in the fibrocartilage. If the increased signal stays entirely within the substance and does not reach the surface, it may represent degeneration rather than a tear. The described finding—disruption of the meniscal contour with signal extending to the articular surface—best fits a true tear. Osteophyte formation reflects degenerative osteoarthritis, not a tear by itself. ACL laxity points to an anterior cruciate ligament injury, not a meniscal tear. Joint effusion alone can accompany many knee conditions and does not confirm a tear.

A meniscal tear on MRI is confirmed when there is abnormal high-signal within the meniscal substance that extends to an articular surface or when the meniscal contour is disrupted by a cleft. This pattern shows a real tear that communicates with the joint space, indicating a split in the fibrocartilage. If the increased signal stays entirely within the substance and does not reach the surface, it may represent degeneration rather than a tear.

The described finding—disruption of the meniscal contour with signal extending to the articular surface—best fits a true tear. Osteophyte formation reflects degenerative osteoarthritis, not a tear by itself. ACL laxity points to an anterior cruciate ligament injury, not a meniscal tear. Joint effusion alone can accompany many knee conditions and does not confirm a tear.