If we examine the cellular structure and system of the cartilage within your joints, you will find that it is built from specific cells (chondrocytes) suspended within a matrix, essentially a net, of additional cells.
When the chondrocytes are exposed to specific insults, whether mechanical or due to altered chemistry within the joint (we’ll get into how that happens later), this altered chemistry than affects the health of the chondrocytes. When the balance, or overall health of these cells within the cartilage are disturbed, in time this triggers “cross-talking” with all of the other structures in and surrounding the knee. 1
When the health and structure of the joint is disrupted, inflammatory chemicals are produced (more on that in a minute). Initially the inflammatory chemicals attempt to stimulate healing or regeneration of the cross-talking tissues. If the insult, whether mechanical or chemical, can be removed, then the body as well as the joint has great innate potential to return to a balanced, resilient, and healthy state. If the insult cannot be removed (such as from a trauma), or is not altered or removed (improper nutrition, excessive weight on the joint, faulty body mechanics or posture), then the inflammation persists and becomes chronic.
When inflammation becomes chronic, the related inflammatory chemicals are no longer helping to stimulate healing, but instead begin to break down all of the structures within and around the joint.
**Warning: Hard science ahead!**
Once this inflammatory cascade is put in motion, aging and degeneration of the joint is accelerated by:
- Oxidation reactions (you can think of oxidation like rusting on a car) – Some of the inflammatory chemicals known as free radicals cause oxidative stress compound the damage to the cells within the tissues of the joint. As the cell damage accumulates, aging of the joint accelerates.1
- Accumulation of damaged cell fragments and matrix molecules. The fragments consistent of building blocks of the connective tissue (components like collagen and fibronectin) and joint fluid, or hyaluronic acid (hyaluronan fragments).
- These degenerative fragments and changes in the joint chemistry are what scientists call Damage Associated Molecular Patterns (DAMPs).
- The DAMPs activate a Receptor for Advanced Glycation Endproducts (RAGE) locally expressed in the joint, initiating a cascade of additional in?ammatory chemicals, otherwise known as cytokines, to be produced.2
OK, phew, that is about as heavy as the science will get for now.
That concept is critically important to our future discussion about how we are going to heal and prevent damage to your joints.
If the aging and degeneration continues, overwhelming and outpacing your body’s regenerative capacity to suppress the inflammation and heal the damage, the fall-out continues.
Ligaments responsible for the integrity of the knee become lax and painful, leading to instability of the knee. Your symptoms may include sensations of giving out, buckling, or “not trusting” the knee.
With ongoing instability and progression of osteoarthritis, the meniscal structures can show advanced degeneration, or even tear, due to sub-optimal support and motion of the knee.
The supportive muscles around the joint become inhibited, weak, and begin to atrophy. In so, the muscles, and their tendons (attachments to the bones) will become injured, strained, or even torn due to overuse as they attempt to stabilize the knee.
Ultimately the entire joint begins to fail due to persistent pain, instability, and loss of optimal function, strength, movement, and necessary support to hold up to the demands of every day life, exercise, and recreation. This is now a combination of structural failure, but also rampant chemical inflammation and cross-talking that will rapidly age your joints.
The spiral can continue downward if the focus of your treatment is overly simplified to a generic, one-size-fits-all, symptom-based management strategy.
The failure of one joint can quickly influence other joints or structures in the musculoskeletal system, locally or more remote. The pain will limit your function. The decreased function will lead to limiting your activity and exercise. The decrease in physical activity will lead to weight gain, further physical dysfunction or disability. And so the spiral continues towards other potential health ailments such as obesity, diabetes, heart disease, and stroke.
Now before your think – “Great picture you painted Dr. Tait! I am now depressed and disheartened by what the future holds for me!” – this is actually exciting!
Exciting you say?
“I just learned my joints are rapidly-aging, cross-talking, degenerating, and I will be using a walker or wheel-chair in no time.”
That is an actual quote from a recent patient after I explained the above during their initial consultation.
What I find incredibly exciting for you (and every patient I share this with in my day to day practice), is that I am going to teach you exactly how to slow down the degenerative aging process regardless of the current health or age of your joints.
More exciting, you will know how to ramp up the regenerative potential of your body, and learn about the Regenerative Medicine procedures now available to treat your joint pain.
Put your hiking shoes on because we’re going to cover some tricky terrain quickly over the coming weeks.
Your trail-guide to healthier joints,
- Lopez-Otin C, Blasco MA, Partridge L, Serrano M, Kroemer G. The hallmarks of aging. Cell 2013;153(6):1194-217.
- Liu-Bryan R, Terkeltaub R. Emerging regulators of the in?ammatory process in osteoarthritis. Nat Rev Rheumatol 2015;11(1):35-44.