Let's cover back pain today.
It's one of the more common things
we see in primary care.
And I wouldn’t be surprised if a lot of
you haven't suffered back pain
at some point in your lives.
Let’s discuss it from an evidence-based perspective.
I’m going to start with a case.
I’ve got a construction worker coming in with back pain.
He is 35 years old, male.
He complains of back pain for the past five days.
He works in construction,
was lifting a 50 kg bag when he
felt acute pain in his lower back.
The pain has since improved,
but he still has occasional
radiculopathy that goes down his right leg.
No previous history of back injury.
So, what's the next best step in his care,
just knowing that baseline history there.
Is it getting an MRI or plain radiographs?
Is it just doing a physical examination
and following up with analgesics?
Or should we think about
referring to an orthopedist?
The answer is C,
physical examination and analgesics alone.
Of course, you want to do
a physical examination,
but we’ll talk about how the natural
history of most cases of back pain,
even if it feels fairly severe at first
and is associated with radiculopathy,
still usually resolves within a couple of months.
the point prevalence at any one time
among adults, of back pain is 12%
whereas the one-month prevalence is 23%
and then 85% of patients in primary care
have some kind of low back pain
at some point in their lives.
And it’s oftentimes related to overuse
and repetitive minor trauma,
but we certainly see cases like this one as well
where it was either due to an accident at work
or motor vehicle accident or something more severe.
So, some key diagnoses to rule out,
and think about when you see patients
with low back pain specifically,
include cauda equina syndrome.
Cauda equina is a back pain
that’s also associated with
specific neurological symptoms.
That include saddle anesthesia
and the problems with bowel and bladder.
Now, that can mean a couple of things.
It can be –
classically, it’s thought of as incontinence,
but actually retention of stool and urine is more
common in cauda equina syndrome than incontinence.
So, that’s something to think about.
The saddle anesthesia, though, has to be
there to define cauda equina syndrome.
And because that's an acute compression
of the spinal cord and its nerves,
it does require an emergent
evaluation by a surgeon.
The other three diagnoses generally
present with more persistent pain,
more severe pain
when you're talking about things like
cancer, abscess and osteomyelitis,
and particularly the latter two
may be associated with
more of a fever with abscess or
osteomyelitis than you might see.
But in those cases that aren’t getting better,
that aren’t following that natural course,
thinking about these diagnoses can be helpful
and then getting early imaging and follow-up.
But they are very rare.
Compared to the wide array of
cases we see of back pain
due to repetitive injury
or minor trauma,
cases of things like osteomyelitis
or cancer are incredibly rare.
So, one of the questions is,
well, what about imaging?
Why not get started with x-rays?
Why not start with MRI?
And the question I would pose back is
does that really change your management
in most cases of low back pain?
And in fact, in clinical studies,
early imaging isn’t associated with
a difference in clinical status at 12 months.
And then, you have to consider
just how common changes,
particularly the lumbar
spine are as we get older.
So, by age 60 years,
up to two-thirds of adults
have evidence of disc herniation on MRI.
And about one in five
has evidence of spinal stenosis.
So, it's the rare 60-year-old
who has actually a normal
MRI of the lumbar spine.
So, everybody has something.
But the fact is that those
don't necessarily correlate well at all
with the degree of pain
and disability among patients.
So, therefore, that's –
those are the limitations of imaging.
Like a lot of things in
orthopedics with imaging,
I really think about getting imaging when we’re going
to do something about the pain and disability,
such as concerning injection therapy or even surgery.
That's the time to order imaging,
not at an early stage
when you still want to give
conservative management a good try.