00:00
So what causes osteoarthritis?
this one's easy.
00:05
Despite being the most common,
chronic, degenerative joint disease,
afflicting nearly everybody
over the age of 50,
the etiology of osteoarthritis
remains completely unknown.
00:16
We do, however, at least know
some of its risk factors.
00:19
Anyone over the age of 65 has osteoarthritis and
oftentimes it can start considerably earlier.
00:25
Female gender is a risk factor, any
family history, prior joint trauma
and certainly obesity by virtue of
excess wear and tear on those joints.
00:34
In addition, osteoarthritis can be secondary to other disease
processes like diabetes, hemochromatosis, acromegaly
and even gout can cause
osteoarthritic types of manifestations.
00:46
So, let's go back to our case for a
moment and look for some key features.
00:50
We have an acute-on-chronic picture,
very typical for osteoarthritis.
00:54
Worse after activity but morning
stiffness lasting for less than 15 minutes.
00:59
Also, typical of osteoarthritis.
01:02
The swollen joint can happen as an acute
synovitis on a backdrop of chronic osteoarthritis.
01:08
It's not common but it
does certainly happen.
01:11
Bony enlargement of the knees due to
these osteophytic growths around the pes
is common especially on radiographs.
01:17
and the fact that you have tenderness on the
medial joint line also supports that condition.
01:23
So, to recap:
Classic features of osteoarthritis
are those we had in our case.
01:28
A chronic disease with periodic flares,
typically precipitated by increased activity.
01:33
You're also looking for asymmetric symptoms and with
inexorable progression osteoarthritis of some joints
can literally bring many
people to their knees.
01:43
See what I did there?
Now, it has a predilection
for certain joints.
01:48
Like the knees, the hips, the lumbar spine
and of course shown here on the left,
the proximal interphalangeal and the distal
interphalangeal joints of the fingers.
01:58
Classic physical exam findings as I
alluded to are gonna be bony enlargement,
a limited range of motion, varus deformity
which means being somewhat bowlegged,
crepitus by palpating
the knee while moving it
and of course, joint-line
tenderness as I've mentioned.
02:14
So let's take a look at some of the common
radiographic features of osteoarthritis.
02:18
The picture on the left here is
a normal radiograph of a knee
and the one on the right is somebody
with severe osteoarthritis.
02:25
What you can see right off the bat, the first
distinguishing feature is the joint space narrowing,
particularly in the medial
compartment of the knee.
02:32
In addition, you can see
evidence of subchondral sclerosis
which is that hyperlucent
areas just on the tibial plateau.
02:39
There's evidence of subchondral
cyst in there as well
and osteophytes basically
broaden the size of the knee
relative to the size of the tibial plateau.