WHAT CAUSES OSTEOARTHRITIS PAIN IN JOINTS INCLUDING WRISTS.
DEAR DOCTOR :
I have osteoarthritis. Can you tell me what is happening in my joints that causes my painful symptoms?
The short answer is that osteoarthritis causes deterioration of cartilage in the joints. But I suspect you’d like a more detailed response.
There are many different kinds of arthritis, but osteoarthritis is the most common. It causes pain, swelling and stiffness in the joints that worsens over time. The condition most often affects joints found in the shoulders, WRISTS, fingers, hips and knees. These joints are designed for a variety of movements that make possible all manner of activity, from playing tennis to playing the piano.
Joints, like machines with moving parts, are vulnerable to friction. If a machine’s moving parts come in contact with one another, friction will scratch the surfaces and cause pitting, distortion and eventually breakage. Two strategies can prevent such friction: applying a lubricant, or inserting a cushion. Human joints are protected in both ways.
The joints affected by osteoarthritis are lined with a membrane, called synovium, that produces synovial fluid. Synovial fluid lubricates the joint, guarding against friction and allowing movement.
In addition, the ends of the bones in these joints are covered by a protective layer of cartilage. The tough, elastic cartilage cushions the bones. Cartilage can mold to its surroundings, so the opposing surfaces of a joint are perfectly matched.
As cartilage becomes less resilient, microscopic pits and fissures appear on its surface. Tiny pieces of cartilage may flake off into the area surrounding the joint, and the damaged cartilage can set off a chain of events that results in joint inflammation.
As cartilage degenerates, patches of exposed bone appear. Over time, the space between bones narrows. The surfaces of the bones change shape, leading to friction and joint damage.
The bones try to repair themselves, but the renovation attempts are uneven. As a result, bony overgrowths form along the margins of the damaged joints. These little pieces of overgrown bone can get chipped off of the bone. Then they become like gravel in the joint, making it hurt worse. (I’ve put an illustration of the process below.)
The combination of damaged cartilage, bone rubbing on bone and inflammation all contribute to your symptoms of osteoarthritis.
So that’s what osteoarthritis is. But you asked what causes it. Medical research has provided some answers. We know that part of it is genetic: It runs in families. It ran in my family. We are born with a vulnerability for our joint cartilage to become damaged if we injure the joint. If there is no injury, we escape getting osteoarthritis.
But when a joint is injured by some trauma, such as a job requiring lots of heavy lifting or (as in my case) a sports injury, the cartilage starts to digest itself. How do our genes trigger this process? Once we understand that, treatments to prevent the disease could follow. more