The Meniscus Tear: A Review of Stem Cell Therapies

Abstract

Meniscal injuries have posed a challenging problem for many years, especially considering that historically the meniscus was considered to be a structure with no important role in the knee joint. This led to earlier treatments aiming at the removal of the entire structure in a procedure known as a meniscectomy. However, with the current understanding of the function and roles of the meniscus, meniscectomy has been identified to accelerate joint degradation significantly and is no longer a preferred treatment option in meniscal tears. Current therapies are now focused to regenerate, repair, or replace the injured meniscus to restore its native function. Repairs have improved in technique and materials over time, with various implant devices being utilized and developed. More recently, strategies have applied stem cells, tissue engineering, and their combination to potentiate healing to achieve superior quality repair tissue and retard the joint degeneration associated with an injured or inadequately functioning meniscus. Accordingly, the purpose of this current review is to summarize the current available pre-clinical and clinical literature using stem cells and tissue engineering for meniscal repair and regeneration.

Keywords: meniscal regeneration; meniscal repair; meniscus; stem cell; tissue engineering.

Figure 1

Schematic diagram of the axial section at the level of the tibial plateau depicting the anatomy, attachments, and relations of the menisci. MM, Medial Meniscus; PCL, Posterior Cruciate Ligament; LM, Lateral Meniscus; ACL, Anterior Cruciate Ligament.

Figure 2

Schematic cross-sectional diagram of the meniscus displaying the circumferential arrangement of collagen fibers and radial tie fibers.

Figure 3

Schematic cross-sectional diagram of the body of the meniscus representing the vascular zones of the meniscus.