Cellular and molecular meniscal changes in the degenerative knee: a review

BACKGROUND: The important role of knee menisci to maintain adequate knee function is frequently impaired since early stages of knee joint degeneration. A better understanding of meniscal impairment may help the orthopaedic surgeon to orient the treatment of the degenerative knee. This review focuses on changes in meniscal cells and matrix when degeneration is in progress. MAIN BODY: Differences in the meniscal structure and metabolism have been investigated in the degenerative knee, both in experimental animal models and in surgical specimens. Cell population reduction, extracellular matrix disorganization, disturbances in collagen and non-collagen protein synthesis and/or expression have been found in menisci along with knee degeneration. These changes are considered disease-specific, different from those due to aging. CONCLUSION: Significant cellular and matrix differences are found in menisci during knee degeneration. These investigations may help to further progress in the understanding of knee degeneration and in the search of more biological treatments.