Mechanical back pain: Clinical sciences

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Introduction0:00–1:31

Mechanical back pain refers to pain arising from the joints, intervertebral discs, nerves, and soft tissues of the spine.
It accounts for the majority of back pain cases, with etiologies ranging from benign musculoskeletal causes to conditions associated with severe neurological deficits.
Now, let’s take a moment to review the anatomy of the spine, starting with the vertebra itself. The anterior portion is known as the vertebral body, while the vertebral arch makes up the posterior and lateral aspects.
Projections from the vertebral arch include the spinous and transverse processes as well as the articular processes that make up the facet joints.
The pedicles are the bony elements connecting the body to the arch, while the lamina connects the transverse and spinous processes.
This circle of bone creates the spinal foramen, and when joined together, adjacent vertebrae form the spinal canal. Laterally, the intervertebral neuroforamen is formed.
The intervertebral disc lies between each set of adjacent vertebrae, creating the anterior intervertebral articulation, while the paired facet joints are located posteriorly.
Now, several ligaments stabilize these articulations, including the ligamentum flavum, which attaches to the anterior surface of each vertebral arch.
Finally, the spinal cord courses through the spinal canal and gives off spinal nerves at each intervertebral level, which exit through the neural foramen.

H&P1:31–1:52

Okay, if your patient presents with chief concern suggesting mechanical back pain, first perform a focused history and physical examination.
Your patient will report back pain, while the physical exam might reveal tenderness to palpation of the spinal and paraspinal structures, as well as hypertonicity of surrounding musculature.
At this point, you can diagnose mechanical back pain, so your next step is to assess your patient for red-flag signs and symptoms!

Mechanical back pain1:52–2:25

These include 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.
Okay, if red flag symptoms are present, obtain a spinal X-ray and assess for the underlying cause. First, let’s discuss spinal fracture!

Spinal fracture2:25–3:41

Most often, you’ll have an elderly patient who reports localized back pain that worsens with bending. They might have a history of trauma, corticosteroid use, osteoporosis, cancer, or an inflammatory disease like ankylosing spondylitis.
Additionally, the physical exam reveals localized tenderness to palpation over the spinous process, while the spinal X-ray typically shows a vertebral deformity.
At this point, you should suspect a spinal fracture, so order a spine CT and MRI. CT is preferred to evaluate bony abnormalities, and can confirm the diagnosis of spinal fracture, while MRI is better for visualizing soft tissue abnormalities like impingement of neural elements!
Treatment consists of lifestyle modifications, primarily rest and a brace to help stabilize the spine. Another important part of treatment is physical therapy, as well as pharmacologic therapy, starting with NSAIDs or acetaminophen.
If pain persists, consider adjuvant medications or a short trial of opioids. Additionally, if your patient has osteoporosis, consider medications like bisphosphonates.
Finally, don’t forget to consult your surgical team for possible vertebroplasty or kyphoplasty. Now moving on to spinal stenosis!

Spinal stenosis3:41–4:40

Your patient will report pain, sensory loss or weakness in their back, buttocks, and legs that’s generally worse with extension, such as standing and walking, but relieved by activities that create flexion, such as sitting or leaning forward, like pushing a shopping cart.
The physical exam could reveal focal weakness, sensory loss, and decreased deep tendon reflexes. Additionally, spinal X-ray might show degenerative changes, loss of intervertebral space, and possibly a vertebral fracture or deformity.
With these findings, suspect spinal stenosis and order an MRI! If the MRI reveals a narrowing of the spinal canal with possible impingement of neural elements, you can diagnose spinal stenosis!
Treatment includes lifestyle modifications, physical therapy, and pharmacologic therapy to help manage pain. Finally, don’t forget to consult your surgery team for possible treatment options, such as laminectomy.
Okay, now let’s move on to disc herniation! These patients report midline pain that increases with spinal flexion, with possible radiation to the buttocks and legs.

Disc herniation4:40–5:51

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.
To perform this maneuver, position the patient supine and raise their straightened leg to at least 80 degrees. If the patient reports reproduction of the radicular pain, the test is positive.
These findings suggest the presence of nerve root impingement. Next, spinal X-ray might show a loss of intervertebral space.
At this point, you should suspect disc herniation, so, again, order an MRI. If the MRI 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!
Treatment includes lifestyle modifications, physical therapy, pharmacologic therapy like NSAIDs or corticosteroids, or even a short trial of opioids.
Finally, don’t forget to get a surgical consult! Okay, let’s go back and discuss patients without red flag symptoms.

Muscle strain or sprain5:51–6:40

In this case, first, assess for muscle strain or sprain. These patients typically report a recent overuse injury, such as gymnasts with repetitive movements involving the spine.
They’ll also experience increased pain with movement and decreased pain with rest. On physical exam, you’ll notice muscle tenderness and spasm, decreased range of motion, and a normal neurologic exam.
With these findings, diagnose muscle strain or sprain, and proceed with treatment and lifestyle modifications, encouraging the patient to maintain physical activity and avoid bed rest.
Other treatment modalities include physical therapy, as well as pharmacologic therapy to relieve pain and spasm, such as with muscle relaxants like cyclobenzaprine.

Spondylosis6:40–8:14

Now, if you rule out muscle strain or sprain, obtain a spinal X-ray and assess for the underlying cause. First, let’s discuss spondylosis!
Your patient will report pain that worsens with lumbar extension and rotation, and improves with lumbar flexion and rest.
Physical exam typically reveals a normal neurological exam, and tenderness to palpation over the facet and sacroiliac joints.
Spinal X-ray may show loss of intervertebral space, osteophyte formation, and facet joint hypertrophy. With these findings, diagnose spondylosis.
Treatment includes lifestyle modifications, such as maintaining physical activity and avoiding bed rest, as well as physical and pharmacologic therapy.
Here’s a clinical pearl! Lumbar spondylosis refers to the degenerative changes of the spine, including desiccation of the intervertebral disc, narrowing of the disc space, and osteoarthritis of the facet joints.
In order for the spine to stabilize itself due to these changes, osteophytes form on the edges of the vertebral body, the facet joints hypertrophy, and the ligamentum flavum thickens.
Unfortunately, these adaptive changes can individually or collectively cause mechanical back pain. The desiccating disk causes discogenic pain; while the arthritic facets cause axial, or midline back pain.
Finally, hypertrophy of the facet joints and ligamentum flavum narrows the spinal canal and neural foramen, potentially impinging on neural elements and causing neurogenic pain!

Spondylolysis8:14–8:54

Next up is spondylolysis! These individuals are typically young athletes participating in sports requiring repeated hyperextension of the lower back.
This includes gymnastics, rowing, wrestling, and track and field sports. Your patient will report pain with lumbar extension.
Physical exam might reveal palpable asymmetry of the spinous process due to displacement of the vertebrae. Spinal X-ray will show a defect in pars interarticularis, which confirms the diagnosis of spondylolysis!
Treatment includes lifestyle modifications, with or without a brace, as well as physical and pharmacologic therapy. Finally, let’s move on to spondylolisthesis!

Spondylolisthesis8:54–10:54

These patients typically report back pain radiating to the buttocks and posterior thigh, and their exam will reveal a palpable step-off over the spinous process due to displacement of the vertebrae, which could result in strength and sensory deficits.
Spinal X-ray shows sagittal vertebral displacement, sometimes with a defect in the pars interarticularis. With these findings, diagnose spondylolisthesis!
Treatment includes lifestyle modifications, with or without a brace, as well as physical and pharmacologic therapy. Now a clinical pearl!
Individuals with spondylosis, spondylolysis, and spondylolisthesis can also present with nerve root compression and neurological symptoms.
In this case, the patient will report not only back pain, but also pain, numbness, or tingling that radiates to their buttocks and legs depending on the affected neural structure.
So, don’t forget to reevaluate your patient if neurological symptoms develop, at which point you should obtain an MRI and surgical consultation.
Before you go, one last clinical pearl! Regardless of the underlying cause of mechanical back pain, it’s important to use a step-wise approach to pain management in order to provide adequate pain relief while avoiding adverse effects.
First-line treatment includes non-opioid analgesics, such as NSAIDs and acetaminophen. Next, add adjuvant medications, which include anticonvulsants like gabapentin, antidepressants like duloxetine, and muscle relaxants like cyclobenzaprine.
For inadequately controlled pain, consider a trial of a weak opioid analgesic, like tramadol. In severe cases, you may consider using a longer trial of a more potent opioid, like oxycodone or fentanyl, but be sure to monitor closely for undesirable outcomes like opioid induced constipation, physical dependence, or even medication misuse.

Review10:54–11:46

Alright, as a quick recap… Mechanical back pain refers to any pain that arises from the joints, intervertebral discs, nerves, or the soft tissues of the spine.
If your patient has red flag symptoms, obtain a spinal X-ray. Next, use history, physical exam, and MRI to assess for spinal fracture, spinal stenosis, and disc herniation.
On the other hand, if your patient doesn’t have any red flags, first rule out a muscle strain or sprain, which is a clinical diagnosis.
If there’s no muscle strain or sprain, obtain a spinal X-ray to identify conditions like spondylosis, spondylolysis, or spondylolisthesis.
Treatment of mechanical back pain primarily consists of lifestyle modifications, as well as physical and pharmacologic therapy, using a step-wise approach to pain management.
Lastly, you might want to consult your