More than 50 years ago, researchers discovered that adult stem cells contained within our bone marrow have the ability to perform a number of healing functions. Your doctor may also use the terms “mesenchymal” or “somatic” in place of “adult.” Like a college student whose major is “undeclared,” these cells are in a stage where they haven’t yet decided what type of cell to be.
Stem cells help to create new cells in existing healthy tissues and may help to repair tissues in those structures that are injured or damaged. They are the basis for the specific cell types that makes up each organ in the body.
When stem cells divide they create progenitor cells. Unlike stem cells, progenitor cells can become cells with more specialized functions, such as brain cells, red blood cells or – of particular interest to orthopaedic surgeons—components of specialized tissue such as bone or cartilage.
Orthopaedic surgeons have focused their attention on mesenchymal stem cells. Unlike embryonal stem cells, mesenchymal stem cells are obtained from living adult tissue.
Bone marrow stromal cells are mesenchymal stem cells that, in the proper environment, can differentiate into cells that are part of the musculoskeletal system. They can help to form trabecular bone, tendon, articular cartilage, ligaments and part of the bone marrow.
Adult stem cells were once believed to be more limited than embryonic stem cells, only giving rise to the same type of tissue from which they originated. But new research suggests that adult stem cells may have the potential to generate other types of cells, as well. For example, liver cells may be coaxed to produce insulin, which is normally made by the pancreas. This capability is known as plasticity or transdifferentiation.