So in an infectious arthritis, you have destruction of the articular cartilage
and the adjacent cortex and this can happen within 24 hours of initial infection.
You can have adjacent periosteal reaction and you actually have more sensitivity
and demonstration of a joint effusion when you are using an MRI.
So it?s actually hard to see some of these findings radiographically.
On an MRI you can also see enhancement of the synovium
which is very helpful when diagnosing an infectious arthritis.
Here we have a plain film of a patient with an infectious arthritis
and you can see destruction of the boney cortex at the level of the infection.
And you can also see soft tissue swelling and soft tissue gas
adjacent to the site of the infectious arthritis.
So neuropathic arthritis is also called a charcot joint.
It?s caused by lack of sensation to the affected joint
while the mobility remains maintained so the patient is able to move the joint?s base around
but they can?t tell if they?re having any pain to the area.
This results in the joint being stressed beyond normal
which result in multiple asymptomatic or mildly symptomatic microfractures
and the most common cause of this is a patient with diabetes.
So the imaging features include extensive subchondral sclerosis,
bony fragmentation which is actually a key feature, periosteal reaction,
and bony and joint destruction. You can see in this patient,
we have destruction and fragmentation of the first digit and tarsal bones
so all of these appear destroyed. You can compare this with the normal bony structures
of the rest of the digits. You actually have changes of the distal second digit
from a prior amputation here. So these findings which are both acute and chronic,
so the chronic finding of the amputation as well as the more acute finding
of the destruction and fragmentation are highly suggestive of a diabetic foot
and this is very commonly seen again in patients with diabetes.
So let?s take a look at this case, this patient is presenting with right sided hip pain.
So what are the different findings that you see here?
So you can see that this is the femoral head and you can see the adjacent acetabulum.
Both of them appear abnormal.
So this right hip has joint space narrowing,
you can almost see obliteration of the joint space here, there?s very little lucency present.
You have osteophyte formation right here, as well as at the margins up here.
You have subchondral sclerosis, so you have an increase in density
in the surrounding bone here and you have multiple cystic changes
which you can see scattered all around this joint.
So this is an example of osteoarthiritis.
This patient has hip pain because of degenerative osteoarthiritis,
again, one of the most common types of arthritis that we can see.
So in this lecture we?ve reviewed several different types of arthritis
and some of the common imaging findings associated with each one.
Often times, patients come in with joint pain and they start off by having a radiograph
so having a general knowledge of the different types of arthritis
and the differences between each one is always helpful
to help the clinical physician know which direction to go.