What
is Osteoarthritis?
Close to 16 million Americans have osteoarthritis – the most
common type of arthritis. Although osteoarthritis can occur at any
age, it most often begins in people in their 50’s and 60’s.
Osteoarthritis or degenerative disc disease is a disorder of
cartilage – the gristle that covers the ends of long bones.
Cartilage is made of cell called chondrocytes which sit inside a
framework made up of collagen and proteoglyens. Under normal
conditions, chondrocytes make collagen and proteoglycens – in
other works – they make the framework they sit inside. With
osteoarthritis, chondrocytes behave abnormally and begin to make
destructive enzymes such as collagenasese, stromelysin and others.
These enzymes degrade cartilage…these enzymes also attract
inflammatory cells which secrete substances called cytokines which
cause further inflammation and damage to cartilage, underlying bone,
and the joint lining.
This process results in progressive pain, stiffness, and loss of
function.
Joint pain and stiffness are the most noticeable symptoms of
osteoarthritis. Morning stiffness is usually brief lasting less than
15 minutes. Osteoarthritis usually affects weight bearing areas
particularly the neck, low back, hips and knees.
It may also affect the fingers and hands and bony knobs may
appear at the finger joints. The base of the thumb may also be
affected. The typical pattern of osteoarthritis in the hands
involves the distal and proximal interphalangeal (DIP and PIP)
joints of the fingers, and the carpometacarpal (CMC) joint of the
thumb.
Osteoarthritis is considered to be a degenerative joint disease.
Along with inflammation, there is wear and tear on the inside of the
joint.
This causes damage to the cartilage (the substance that forms the
surface of the joints and works as a shock absorber). As the
cartilage wears thin, the underlying bone is damaged. This process
results in progressive pain, stiffness, and loss of function.
Osteoarthritis does not need to be disabling and with the proper
medical care can be managed easily.
Source: Nathan Wei
Dr. Wei (pronounced “way”) is a board-certified
rheumatologist and Clinical Director of the nationally respected
Arthritis and Osteoporosis Center of Maryland. He is a Clinical
Assistant Professor of Medicine at the University of Maryland School
of Medicine and has served as a consultant to the Arthritis Branch
of the National Institutes of Health.
