Meniscus Tears: A Cause of or Consequence of Knee Osteoarthritis?

Meniscus pathologies are common in the general population, in particular disruption of the integrity in the form of meniscal tears which may occur both after acute knee injury but also develop more slowly without history of knee trauma. Meniscal tears with loss of meniscal function are associated with increased risk for development of knee osteoarthritis, but it is also plausible that degenerative changes of the meniscus leading to tears (due to tissue fatigue) may represent “osteoarthritis of the meniscus”. There are profound tissue alterations of the meniscus occurring in osteoarthritis with degradation of the meniscal collagen bundles and increased prevalence of calcifications. When a meniscal tear (or a degenerative meniscal lesion) is found in a knee where the patient reports knee symptoms, e.g. on MRI, the tear is often assumed to be the direct cause to the symptoms. While certain traumatic meniscal tears, in particular with large unstable fragments, may cause knee pain, catching or locking symptoms, the evidence are scarce for many other common meniscal tear configurations. An alternative explanation is that knee symptoms may often be related to other processes in the knee associated with the biomechanical failure of the torn or degraded meniscus and osteoarthritis development.