Pathophysiology of meniscus injuries comprises a combination of compressive, tensile, and shear forces. Besides the characteristics of the tissue itself, which comprises segmental and zonal variations, several other factors are enrolled in the etiology of meniscus tears. These include the external load/traumatic event in a given moment, the joint alignment, age, body mass index, or patient’s activity level. On the other hand, degenerative tears are usually multifactorial and not always easy to separate from the environment of a globally osteoarthritic joint. Herein, it is overviewed the most important features of anatomy, biology, and biomechanics contributing to the most frequent injury mechanisms for traumatic and degenerative meniscus tears for all ages.