A Brief Overview of Osteoarthritis
Musculoskeletal joint conditions are extremely prevalent in the US. Osteoarthritis (OA) is the most common of the dozens of forms of arthritis. The Center for Disease Control and Prevention predicted that by 2020, arthritis will gain more patients than any other disease form in America 1, 2. OA can affect any joint but most often occurs in the fingers, wrists, knees, hips, lower back, and neck. Typical symptoms include joint pain, swelling, redness, stiffness, instability, immobility, or crepitus (crackling, popping, or squeaking sounds emanating from the joint). Because OA is a degenerative disease related to “wear and tear” of the cartilage in the affected joint, symptoms gradually worsen over time. Age is the biggest risk factor for OA being most common in adults 50 years and older and more often in women than men. However, trauma to the joint due to accidents or sports injuries are significant risk factors for developing the disease.
Cartilage degeneration and current treatment modalities
In this article, we take a more detailed look into how OA affects the cartilage and how regenerative medicine works to counteract the progression of OA alleviating pain, restoring mobility, and helping patients avoid surgery.
Three Types of Cartilage and Where They Are Found in the Body
Let’s start by describing what cartilage is, the three types, and where it’s found. Cartilage is a type of connective or supportive tissue. It is a precursor to bone in the developing embryo but remains dispersed throughout the body in adults, especially to cover the joints. Cartilage is interesting because, unlike most tissues, it does not contain nerves or blood vessels (avascular). Instead, the cells that cartilage is composed of, the chondrocytes, receive nutrients from the gel-like matrix inside the cartilage. This special structure gives cartilage its strong and flexible characteristics.
There are three types of cartilage, two of which are relevant to regenerative medicine. The first is the elastic type, found in the ear, throat, nose, and trachea. The second is fibrous, and is found in pads called menisci (singular, meniscus) and in spinal vertebrae. These are vital to reduce friction in areas such as the knee. Considered the strongest of the three types, it is heavily composed of strong collagen fibers. Third is hyaline or articular cartilage, this is the most common type of cartilage found in the larynx, nose, ribs, trachea, and on bony surfaces at joints. Its main function is to provide a smooth, lubricated surface for low friction movements. At joints, hyaline cartilage is formed into a thin layer cover or sheath at the end of a bone and is the weakest of the three types (see Figure 1).
The mechanical forces cartilage must absorb to protect the underlying bone are not insignificant. Overtime, the outer layers of cartilage begin to wear down increasing the friction between abutting bones. Normal wear and tear becomes more pronounced with age leading to the degenerative condition osteoarthritis. OA is characterized by a loss of joint space due to damaged or missing menisci or articular cartilage and can be accompanied by the growth of painful bone spurs (see Figure 1).
Cartilage damage and Regenerative Medicine for Osteoarthritis
Because cartilage is avascular (does not contain blood vessels) it does not receive growth factors and other nutrients from the blood. Thus, it has a limited capacity for self-repair. The cartilage matrix is composed mainly of water, collagen, and proteoglycans, all of which contribute to the ability of cartilage to withstand compressional forces. Chondrocytes, the resident cell type in cartilage that secrete the matrix, make up only about 5% of the mass of cartilage.
It is often the objective of regenerative medicine or stem-cell therapies to expand the number of or improve the function of resident cells in diseased tissue to counteract the degenerative process. Regenerative medicine therapies for OA often rely on special stem cells called mesenchymal stem cells (MSCs) because they can develop into various connective tissues like chondrocytes which can then help to repair damaged cartilage at the affected joint. MSCs can be collected from the patient’s bone marrow, adipose (fat), or perinatal tissues (those from the umbilical cord or placenta). A promising regenerative medicine approach is to use what is termed human amniotic tissue allograft injections, to help rebuild damaged cartilage. Amniotic membranes surround the developing embryo during development and are a rich source of therapeutic cells including stem cells in particular MSCs. When injected into diseased joints it has been shown that the MSCs can develop into chondrocytes which then act to grow and repair cartilage. The amniotic tissue allograft injections also contain other cells that act as scaffolding for chondrocytes to grow and contain a variety of growth factors which are proteins secreted by cells to stimulate the growth of resident cells. Other proteins present are anti-inflammatory and antibacterial in nature. Often, amniotic tissue allografts are used with other treatments such as Platelet Rich Plasma injections and concentrated Growth Factor injections. Both procedures act to increase growth factor production at the damaged joint in order to enhance the number and function of cartilage producing chondrocytes.
Conventional treatments are unable to affect the function or number of chondrocytes at an osteoarthritic joint. Instead, conventional therapies work to reduce inflammation and pain using NSAIDs or steroid injections (e.g., cortisone shots). Long-term exposure to drugs like cortisone can have significant side effects and must therefore be used with caution. Some side effects include: cartilage loss, tendon injury, infection, fat loss at injection site, and elevated blood sugar.
To end our discussion of OA, it is important that note if you have received a diagnosis of OA one should always consult with their doctors armed with knowledge and questions in order to determine the state of their disease, what treatment options are available, and whether they are a good candidate for certain treatments. At StemX we are always available to discuss the best treatment options for your particular situation and what may be covered by your insurance.
Founded in 2017, StemX is located at 124 Lomas Santa Fe Dr., #206, Solana Beach, CA and can be reached at 760- 810-4104. We provide regenerative medicine services for orthopedic, joint, muscle, and tendon injuries. Our staff is specially trained in regenerative treatments providing natural, non-surgical therapy to repair, rebuild joints and cartilage in - knees, shoulders, ankles, hips, backs, necks, and more. Typically, with one treatment and minimal to no downtime, StemX is on the cutting edge of regenerative medicine for orthopedics. We enable patients to get out of chronic pain and increase mobility without the need for surgery.
Article written by the StemX Team
- Centers for Disease Control and Prevention (CDC) Arthritis prevalence and activity limitations: United States, 1990. MMWR Morb Mortal Wkly Rep. 1994;43(24):433–438. [PubMed] [Google Scholar]
- From the Centers for Disease Control and Prevention. Arthritis prevalence and activity limitation–United States, 1990. 1994;272(5):346–347. [PubMed] [Google Scholar]