Osteoarthritis vs. Osteoporosis
Two bone and joint conditions share a prefix. Do you know the difference?
The two conditions osteoarthritis and osteoporosis sound very similar, and many people get confused. While they share the prefix osteo, which means bones, these conditions are very different.
Osteoarthritis affects the cartilage that covers the ends of bones in joints. Osteoporosis, which translates to porous bones, causes bones to weaken. Both conditions become more common with age.
“A key difference is that osteoporosis is painless unless a fracture occurs and osteoarthritis may cause pain,” says Cleveland Clinic rheumatologist Mathilde Pioro, MD.
What Is Osteoarthritis?
At every joint in your body, two bones meet. With nothing between them, the friction from movement would scratch the surfaces, ultimately leading to distortion and breakage. To prevent this, the ends of bones are covered with a cushioning material called cartilage. Joints are also surrounded by synovial fluid, a viscous liquid that provides lubrication. This allows for smooth, pain-free movements.
As we age, cartilage in joints starts to deteriorate. “Some amount of wear and tear happens to everyone,” says Dr. Pioro. Damaged cartilage and inflammation in the joint can lead to cartilage becoming thinner, providing less cushioning to the bone. This may cause pain, swelling and stiffness, which are the symptoms of osteoarthritis.
The exact cause is not known, but there are some risk factors. A major one is being overweight or obese. “Osteoarthritis primarily affects the weight-bearing joints, such as the hip and knee,” says Dr. Pioro. Therefore, it’s important to try to maintain your weight as close to normal as possible, both to prevent osteoarthritis and to relieve pain if you have it. “Weight loss can have an even greater effect than pain medications on relieving arthritis pain in weight-bearing joints,” says Dr. Pioro.
What Is Osteoporosis?
Bones, the building blocks of our skeleton, may seem static, but they are constantly changing. The cells that make up bone go through cycles of breaking down and building back up. Bone is strongest early in life and reaches peak mass around age 30. As we get older, bones can weaken somewhat, but they generally remain strong enough.
Some, but not all people, develop osteoporosis, in which bone loss outpaces bone build-up to such a degree that bones become fragile and susceptible to fracture. There are several risk factors for osteoporosis, including certain medications (corticosteroids, aromatase inhibitors for breast cancer and others) smoking and genetics.
“A common misconception is that osteoporosis is a condition of women,” says Dr. Pioro. “But both men and women can get it.” Twenty percent of hip fractures occur in men.
Osteoporosis doesn’t cause pain. You won’t know you have it unless you break a bone. Everyone should get screened with a bone density test starting at age 65 for women and age 70 for men. Anyone who has fractured a long bone of the arm or leg or a vertebrae from falling after age 50 or has other risk factors (such as family history of fractures or having taken corticosteroids) should get screened sooner.
Exercise is good for both osteoarthritis and osteoporosis. “For osteoarthritis, it’s important to use the joint within the limits of what the body can tolerate,” says Dr. Pioro. Not being active leads to muscle atrophy and weakness around the joint, which worsens symptoms.
Other treatments for osteoarthritis revolve around pain control. If pain becomes severe, joint replacement surgery is an option.
For both preventing and treating osteoporosis, you need weight-bearing exercise, such as walking, to keep bones strong. Bone strength also depends on getting adequate amounts of calcium and vitamin D. People who have been diagnosed with osteoporosis may need to take a drug, most likely a bisphosphonate, which prevents further bone loss.