Approach to back pain: Clinical sciences

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Introduction0:00–0:31

Back pain is a very common and potentially challenging condition to diagnose. The vast majority of patients have musculoskeletal pain without a specific underlying condition, and improve within a few weeks.
Although back pain is most often benign and self-limited, in some cases it could also be a sign of more severe disease, so these patients require prompt evaluation and treatment.
Okay, if your patient presents with back pain, you should first perform an ABCDE assessment to determine whether your patient is unstable or stable.

Unstable Patient0:31–2:09

If they’re unstable, stabilize their airway, breathing, and circulation. Next, obtain IV access and put your patient on continuous vital sign monitoring, including heart rate, blood pressure, and pulse oximetry.
Finally, if needed, don’t forget to provide supplemental oxygen! Here’s a clinical pearl!
Unstable patients with back pain might present in a few ways. First, your patient might have sepsis due to underlying discitis, osteomyelitis or abscess.
In this case, don’t delay starting IV fluids, obtain an MRI and cultures, and initiate empiric antibiotics! Another common cause of back pain in unstable patients is from a visceral source, such as bowel perforation leading to acute peritonitis.
These patients might present with hypotension and abdominal pain that radiates to the back, so in this case, start IV fluids, empiric antibiotics, and consult the surgery team.
And finally, your unstable patient might have back pain from a vascular source, such as a ruptured aortic aneurysm. So, if your patient presents with hypotension, sudden and severe back pain described as “ripping” or “tearing”, then immediately start IV fluids, obtain a CT angiogram, and consult the vascular surgery team!

Stable Patient2:09–3:05

Now that we’ve addressed unstable patients, let’s go back and discuss stable ones. If your patient is stable, perform a focused history and physical examination.
Your patient will report back pain, while the physical exam might reveal tenderness to palpation of the spinous and paraspinous structures, or tenderness to palpation in the abdominopelvic region.
At this point, diagnose back pain! Next, assess for red flags including age of onset before 20 or after 55 years of age; severe or progressive motor and sensory loss; urinary retention or incontinence; history of cancer or spinal surgery; significant trauma that precedes the onset of pain; prolonged steroid use; and history of HIV.
If red flag symptoms are present, obtain a spinal X-ray and assess for the underlying cause. First, let’s focus on cauda equina syndrome!

Cauda equina syndrome3:05–4:39

The cauda equina is the bundle of nerves at the lower end of the spinal cord, resembling a horse's tail. This region is crucial for transmitting nerve signals to and from the legs and pelvic organs.
Thus, compression or damage of the cauda equina can lead to significant neurological symptoms. Your patient will report progressive motor or sensory loss in the lower limbs, new urinary retention, or urinary or fecal incontinence.
They might also have a history of a spinal tumor or disc herniation. Physical exam typically reveals motor deficits and saddle anesthesia, meaning loss of sensation around the buttocks, perineum, and inner thighs.
You will also note absent or decreased anal sphincter tone. Spinal X-ray may show loss of intervertebral space, which may indicate posterior intervertebral disc bulging, or could show spondylolysis and stenosis of the vertebral canal.
With these findings, consider cauda equina syndrome and order an MRI. If it shows compression of the cauda equina nerves, which is often seen between the levels of L1 to L5, you can diagnose cauda equina syndrome!

Infection4:39–5:31

Moving on to infection! These patients may have a history of a surgical procedure, intravenous substance use, or immunosuppression such as patients with prolonged steroid use or HIV.
Physical exam typically reveals elevated body temperature and you may even observe a wound. Spinal X-ray might show discitis or osteomyelitis, where there is boney destruction, loss of intervertebral disc space, and surrounding soft tissue stranding, but keep in mind that they’re often negative.
So, regardless of the x-rays, with these findings you should still consider an infection causing back pain, and order an MRI and blood cultures!
If the MRI shows an epidural abscess, discitis, or osteomyelitis, and blood cultures return positive, then diagnose an infection.
Okay, let’s move on to malignancy and metastatic spinal disease! This patient may have a history of cancer, unexplained weight loss, and night sweats.

Malignancy / Metastatic spinal disease5:31–6:22

Physical exam typically reveals tenderness to palpation localized to paraspinous tissues. Spinal imaging might show a vertebral tumor or metastatic lesions.
If these findings are present, consider malignancy and obtain a biopsy! If the biopsy is positive for malignant cells, diagnose malignancy or metastatic spinal disease.
Here’s a clinical pearl! Biopsy can also help determine if the tumor is primary or metastatic.
Lung, prostate, and breast cancers are the three most common cancers that tend to spread to the spine. Next, let’s take a look at spinal fractures.

Spinal fracture6:22–7:19

History usually reveals an elderly patient with localized back pain that worsens with bending. They might have a history of trauma, corticosteroid use, or osteoporosis.
Additionally, physical exam reveals localized tenderness to palpation over the spinous process, while the spinal X-ray typically shows a vertebral deformity.
At this point, consider a spinal fracture and order a spine CT and MRI. CT is preferred to evaluate bony abnormalities and confirms the diagnosis of vertebral fracture, while MRI is better for visualizing soft tissue abnormalities like spinal canal stenosis and impingement of neural elements!
With these findings you can diagnose spinal fracture as a cause of back pain. Moving on to spinal stenosis.

Spinal stenosis7:19–8:09

In this case, your patient will report pain, sensory loss or weakness in their back, buttocks, and legs. Pain is generally worse with extension, such as standing and walking, but relieved by flexion, like a sitting position or pushing a shopping cart.
The physical exam could reveal focal weakness and sensory loss, as well as decreased deep tendon reflexes. Spinal X-ray might show degenerative changes, loss of intervertebral space, and possibly a vertebral fracture or deformity.
At this point, consider spinal stenosis and order an MRI. If it reveals narrowing of the spinal canal with possible impingement of neural elements, you can diagnose spinal stenosis!

Disc herniation8:09–9:01

Next up is disc herniation. These patients report midline pain that increases with spinal flexion, with possible radiation to the buttocks and legs.
On the flip side, the physical exam might reveal dermatomal sensory loss or myotomal weakness, decreased deep tendon reflexes, or a positive straight leg raise test where the patient reports reproduction of the radicular pain, which suggests the presence of nerve root impingement.
Spinal X-ray might show a loss of intervertebral space. At this point, consider disc herniation and order an MRI.
If it reveals a tear in the annulus fibrosus or disc protrusion, with possible impingement of neural elements within the spinal canal or at the neural foramen, diagnose disc herniation!
Okay, let’s go all the way back and discuss patients without red flag symptoms. First, assess for muscle strain or sprain, which is a clinical diagnosis.

Muscle strain or sprain9:01–9:45

These patients typically report a recent overuse injury, such as gymnasts and dancers with repetitive back movements, as well as awkward movements such as lifting incorrectly, which may also occur in older patients.
They will also report increased pain with movement and decreased pain with rest. Physical exam will reveal muscle tenderness, decreased range of motion, and a normal neurologic exam.
With these findings, you can diagnose muscle strain or sprain! Now, if your patient doesn’t have a muscle strain or sprain, you can obtain a spinal X-ray and assess for the underlying cause.

Mechanical causes9:45–11:10

First, let’s focus on mechanical causes of back pain! Your patient might report pain increased with range of motion.
They might also report pain in the back, buttocks, and legs. Physical exam typically reveals a normal neurological exam, and you might observe a palpable step off due to vertebral slippage.
Spinal X-ray may show loss of intervertebral space, osteophyte formation, and facet joint hypertrophy. Additional findings can include a defect in the pars interarticularis, or sagittal vertebral slippage.
With these findings, diagnose mechanical back pain, such as spondylosis, spondylolysis, and spondylolisthesis. Here’s a clinical pearl!
If spondylosis, spondylolysis, and spondylolisthesis progress enough to cause nerve root compression, individuals can develop neurological symptoms.
These include pain, numbness, or tingling that radiates to their buttocks and legs depending on the nerve impinged. So, if neurological symptoms develop, be sure to reevaluate your patient, obtaining an MRI and surgical consultation!

Inflammatory causes11:10–12:27

Next up are inflammatory causes of back pain! These patients typically report joint swelling fatigue, and stiffness.
Some may present the classic triad of arthritis, conjunctivitis, and urethritis. Physical exam typically reveals tenderness to palpation of the sacroiliac joint and a limited lumbar range of motion.
Spinal X-ray may show vertebral syndesmophytes, or bony growths arising from the ligaments that fuse the joints resembling a “bamboo spine.” At this point, consider inflammatory causes of back pain and order inflammatory markers, such as ESR and CRP.
Next, check if your patient is positive for the HLA-B27 antigen, which is closely associated with inflammatory arthritis!
You should also obtain nucleic acid amplification tests, or NAATs, for gonorrhea and chlamydia. If ESR and CRP are elevated, sometimes with positive HLA-B27 or gonorrhea and chlamydia NAATs, then diagnose an inflammatory cause of back pain, such as ankylosing spondylitis or reactive arthritis!

Referred pain12:27–13:53

Finally, if spinal x-ray is normal, consider referred pain, which stems from somewhere else! The history and exam might help you find what’s causing the referred pain.
Next, assess for underlying organ involvement. Some patients typically report abdominal or flank pain, and they might reveal nausea, vomiting, night sweats and unintentional weight loss, or dysuria and hematuria.
Physical exam reveals tenderness to palpation of the abdomen or pelvis, and you might palpate an abdominal or pelvic mass.
In this case, consider referred gastrointestinal or genitourinary pain and obtain CT abdomen and pelvis. If the CT reveals visceral changes, such as pancreatitis, nephrolithiasis, or uterine cancer, diagnose back pain referred from a gastrointestinal or genitourinary source.
On the other hand, if history reveals deep abdominal pain that radiates to the back in a patient with a history of tobacco use, hypertension, hyperlipidemia, or coronary artery disease, then consider referred vascular pain and order a CT abdomen and pelvis.
If the CT reveals vascular changes, like aortic dissection, diagnose back pain that’s referred from a vascular source. Alright, as a quick recap… Back pain can be classified based on the presence of red flag symptoms, including motor and sensory loss, urinary retention or incontinence, and history of cancer, spinal surgery, or significant trauma.

Review13:53–14:59

If red flag symptoms are present, obtain a spinal X-ray. Next, use their history, physical exam, MRI, and labs to assess for cauda equina syndrome, infection, malignancy, spinal fracture, spinal stenosis, and disc herniation.
On the other hand, if red flag symptoms are absent, first rule out a muscle strain or sprain, which is a clinical diagnosis.
If your patient doesn’t have this, obtain a spinal X-ray, which may show evidence of either mechanical back pain or inflammatory back pain.
If the spinal X-ray is normal, then obtain additional imaging with a CT abdomen and pelvis to determine your patient’s back pain is referred from a gastrointestinal genitourinary, or vascular source.
Approach to back pain: Video, Steps, and Uses | Osmosis