Almost as sure as death and taxes
The Dutch in old Amsterdam got it
Polar bears in the zoo get it
Cats, Dogs and pigs, too, get it.
Fish don’t but buffalo do.
So do rabbits, So did I –and so will you
Probably.
Osteoarthritis is by far the single greatest
cause of disability in seniors in the US and in all industrialized countries. What causes
it? We thought it was simply "wear and tear or repetitive injury because it seemed to
be found predominantly in the older age group. Recent research, however, suggests that
there may be other mechanisms in play determining who gets it and where it strikes.
The American College of Rheumatology defines osteoarthritis as a group
of disorders of the body joints resulting in deformity, loss of range of motion, and pain.
These are associated with degenerative changes in the articular cartilage and in the
underlying bone.
Osteoarthritis can be primary (idiopathic – short for we
don’t know why this happened) or it can be secondary to other medical conditions such
as chronic inflammation, biochemical, endocrine, anatomic, developmental or metabolic
disorders (secondary osteoarthritis).
Age, obesity, heredity, hormonal variables, osteoporosis, joint
hypermobility, and diseases such as diabetes and hypertension are considered to be
predisposing to osteoarthritis. Mechanical factors such as joint shape, trauma,
(particularly fractures involving joints) occupational and sports stresses, such as ballet
dancing, gymnastics and acrobatics, and high impact sports also play a part. There is no
evidence that recreational exercise of normal joints increases vulnerability. For reasons
not yet fully understood, age is the most powerful predictor of the development of
osteoarthritis. X-ray evidence can be found in over 80% of people over the age of 65.
These become progressively more severe as the person ages. But symptomatic osteoarthritis
is not the inevitable consequence of old age nor is simple aging of joint cartilage the
principal cause of osteoarthritis.
The smooth, shiny articular cartilage is being destroyed and new bone
forms around the edges of the joints, with resulting decreased range of motion, impaired
nutrition and eventual deterioration of the joint. These changes, in turn may be related
to a relative increase in mechanical stresses because the support of the joint (muscular
and ligamentous, cartilage or underlying bone) is inadequate. This may occur even in the
absence of abnormal external stresses. Repetitive abnormal stresses may cause these
changes in the presence of otherwise normal joints and supporting structures. These forces
are usually work-related rather than recreational.
Normal cartilage consists of cells called chondrocytes. These cells are
suspended in a cellular matrix composed of water, collagen arcades providing the
structural framework and clumps of proteoglycan supplying the resilience of the cartilage.
Chondrocytes are the source of both of these substances. Cartilage has no blood supply. It
derives its nourishment from the (synovial) fluid within the joint, as it is
"pumped" by normal joint movement. Loss of this normal movement through either
severe or repetitive trauma or immobilization can lead to demise of the chondrocytes and
consequent cartilage degradation.
The mere presence of osteoarthritic changes on X-ray does not
necessarily signify pain. This fact is particularly significant in regard to spinal
arthritic changes, which are most likely to be asymptomatic. When OA does become
symptomatic, a deep, aching, diffuse pain is the primary symptom. It is usually aggravated
by activity, relieved by rest, but present again on the initiation of movement after rest,
such as after sleeping, prolonged sitting. As a result of the limitations and disturbances
of joint motion due to the arthritis, muscle spasm or tendinitis may be the cause of pain.
Pharmacologic: The primary goal of medication is functional restoration. Complete
relief of pain is neither necessary nor always attainable, and the effort to achieve same
may be counterproductive. This applies in particular to the older population, in which the
over-zealous use of non-steroid anti-inflammatory medications (NSAIDS) may result in
serious consequences. The object of medication is to facilitate sufficient pain
amelioration to permit a fuller participation in aerobic and strength training activities,
in turn, to facilitate self-management.
To this end, the drug of first choice is
acetaminophen (Tylenol, etc.) in doses up to 4 grams per day. Caution in this regard
should be observed in those people with liver disease and those who consume more than two
or three ounces of alcohol per day. NSAIDS, and there are plenty of them out there,
through blocking prostaglandin synthesis provide second line therapy. Probably there is
little difference between them as far as effectiveness and toxicity, primarily involving
the stomach and kidney, but there are some that work better for some people for some
problems sometimes. Bottom line, the cheapest and most effective, with the fewest side
effects is ibuprofen. Recently two new NSAIDS have been introduced. They are COX-2
inhibitors and are claimed to spare the "good" prostaglandins that protect the
stomach. The other precautions in the use of NSAIDS still apply.
Opioids such
as hydrocodone, oxycodone and codeine may be useful for severe or break-through pain. The
old taboos against the use of these medications should no longer restrict their use when
indicated.
Topical preparations such
as capsaicin are useful as local anaesthetics, particularly in small joints. Long term
therapy using a combination of glucosamine and chondroitin (see my earlier newsletters)
holds great promise for pain relief and possibly cartilage protection without significant
side effects.
In spite of a persistent
and pervasive mythology to the contrary, the injection of corticosteroids into arthritic
joints particularly the knees, applied judiciously and sparingly can afford considerable
short-term pain relief without significant downside.
Recently the effects of intra-articular installation of
high-molecular weight hyaluronates (the ground substance of the joint fluid) have
demonstrated short-term (up to 6 months) benefit in both pain relief and joint function
preservation. The ultimate role for this therapeutic approach is not presently known.
Non-pharmacologic: I’ll
devote an entire article to this subject in the next issue of the CSOM Newsletter.
This article will contain 2 graphics
one of a normal knee and one of an osteoarthritic knee.
