| 6s | While regaling you with daring stories from her youth, |
| 9s | it might be hard to believe your grandmother used to be a trapeze artist. |
| 13s | However, the bad backs, elbow pain, and creaky knees so common in older people |
| 18s | is more than just “old age." |
| 20s | In fact, the source of this stiffness plagues many young people as well. |
| 25s | The culprit is arthritis: |
| 26s | a condition that causes inflammation and pain in the joints |
| 29s | of over 90 million people in the U.S. alone. |
| 33s | But are stiff, creaky joints really inevitable? |
| 36s | What makes arthritis so pervasive, |
| 38s | and why haven’t we found a cure for this widespread condition? |
| 42s | The first hurdle is that arthritis is actually a spectrum |
| 45s | of over 100 different arthritic conditions. |
| 48s | All these conditions share symptoms of joint pain and inflammation, |
| 53s | but the origin and severity of those symptoms vary widely. |
| 57s | Even the most common type, osteoarthritis, |
| 59s | is trickier to prevent than one might think. |
| 62s | It’s a general misconception that arthritis is confined to old age. |
| 66s | The origins of osteoarthritis can often be traced to a patient’s early life, |
| 70s | from any seemingly ordinary joint injury. |
| 73s | Following impact, immune cells rush in to help clean and repair the damaged site |
| 78s | and begin pumping out enzymes, |
| 80s | including matrix metalloproteinases and aggrecanases. |
| 84s | These enzymes clear out the damaged tissue and contribute to inflammation. |
| 88s | But while this rapid swelling helps protect the joint during recovery, |
| 91s | inadequately healed tissue can cause these immune cells to overstay their welcome. |
| 96s | The continuing flood of enzymes starts to degrade the cartilage, |
| 99s | weakening the joint and leading to arthritis later on. |
| 103s | Not all forms of arthritis can simply be traced to an old sports injury. |
| 107s | Take rheumatoid arthritis, which affects 1.3 million U.S. adults. |
| 112s | This condition is actually an autoimmune disease |
| 115s | in which autoantibodies target natively produced proteins, |
| 118s | some of which are secreted by cartilage cells. |
| 121s | We still don’t know what causes this behavior, |
| 124s | but the result is that the body treats joint tissue like a foreign invader. |
| 128s | Immune cells infiltrate the joint despite there being no tissue damage to repair. |
| 133s | This response leads to chronic inflammation, |
| 135s | which destroys bone and cartilage. |
| 138s | Yet another condition, spondyloarthritis, |
| 141s | has similarities to both of the conditions we’ve covered. |
| 144s | Patients experience continuous inflammation in the joints |
| 147s | and at the sites where ligaments and tendons attach to bones, |
| 150s | even without any initial injury. |
| 153s | This leads to the flood of enzymes and degradation seen in osteoarthritis, |
| 157s | but is driven by different inflammatory proteins called cytokines. |
| 162s | As the enzymes eat away at cartilage, |
| 164s | the body attempts to stabilize smaller joints by fusing them together. |
| 168s | This process sometimes leads to outgrowths called bone spurs, |
| 172s | which also cause intense stiffness and joint pain. |
| 176s | With so many factors causing arthritis, |
| 178s | our current treatments are tailored to tackle specific symptoms |
| 181s | rather than underlying causes. |
| 183s | These range from promising MACI techniques, |
| 185s | which harvest cells from small pieces of cartilage to grow replacement tissue. |
| 189s | To a technique called microfracture, |
| 192s | where surgeons create small holes in the bone, |
| 194s | allowing bone marrow stem cells to leak out and form new cartilage. |
| 199s | |
| 200s | people with withered cartilage can even undergo full joint replacements. |
| 204s | But outside these drastic measures, |
| 206s | the underlying drivers of autoimmune arthritis |
| 209s | still present a unique treatment challenge. |
| 212s | Scientists are making progress with therapies that block TNF-alpha, |
| 216s | one of the primary proteins causing inflammation in rheumatoid arthritis. |
| 220s | But even this approach only treats the symptoms of the condition, not the cause. |
| 226s | In the meantime, some of our best defenses against arthritis are lifestyle choices: |
| 231s | maintaining a healthy weight to take pressure off joints, |
| 234s | low-impact exercises like yoga or cycling, and avoiding smoking. |
| 239s | These arthritis-fighting behaviors can help us lead longer lives |
| 243s | as we continue to research cures and treatments |
| 246s | for the huge diversity of arthritic conditions. |
