What is the diagnosis?

The patient is presenting with signs and symptoms of sciatica, an umbrella term to describe injury/irritation of the sciatic nerve. 

• Pearl: In most cases, as with the patient above, this is caused by a Lumbar Disc Herniation [5]. Other less common etiologies for sciatica include spinal stenosis, spondylolisthesis, piriformis syndrome and neoplasm [1].

What is the mechanism of injury?

When repeated mechanical stresses are applied to the axial spine, the fibrous layer becomes defective over time. A sudden, acute injury may cause the extrusion of the nucleus pulposus through a failing outer layer [8]. 

• Pearl: The posterolateral aspect of the annulus fibrosus is often the thinnest part, making it prone to herniations and nerve root compressions [2].

What physical exam findings are expected?

Physical exam findings correlate best with the location and level of the disc herniation. Approximately 95% of disc herniations in the lumbar area occur at L4-L5 or L5-S1 [2]. Extreme lateral herniations at this level typically cause an L4 radiculopathy, while a paracentral or lateral disc herniations cause an L5 radiculopathy. 

• Pearl: The L4 nerve root is responsible for the patellar reflex, sensation to the anterior and medial thigh and extension at the knee. 

• Pearl: The L5 nerve root is responsible for sensation to the lateral lower leg, sensation to the dorsum of the foot and first web space, and toe/foot dorsiflexion [3].  

Which imaging modalities can be used?

Lumbar X-rays are often the first line imaging for lower back pain to evaluate alignment of the spine, signs of degenerative changes and bony injury. However, MRI is the gold standard for confirming suspected disc herniation. This is typically reserved for suspected disc herniations with significant pain or persistent motor deficits, and typically obtained in the outpatient setting. An MRI should be emergently performed when complications such as Cauda Equina are suspected.  

What is the management in the ED?

In the Emergency Department, the priority is to evaluate for the limb threatening complication of Cauda Equina or conus medullaris. These syndromes describe compression of the distal spinal cord and can cause irreversible nerve damage if not acted upon quickly. “Red flag” signs of this include bowel/bladder difficulties, saddle anesthesia, sphincter disturbance, gait instability and leg weakness [6].

Most symptomatic presentations of disc herniations resolve non operatively and are therefore usually managed conservatively. In the Emergency Department, anti-inflammatory agents are first line therapies. Oral steroids for radicular pain appear to have a modest improvement in function, though research is limited. The side effects of systemic steroids should always be considered before prescribing them to a patient [4]. Lastly, counseling patients on targeted physical therapy exercises (i.e. Mckenzie method) is an important rehabilitation tool, especially if the symptoms last longer than a few weeks [7].

When do you consult orthopedics?

You should involve orthopedics when you think the patient is a candidate for emergent or urgent surgical intervention. This would include cases where you suspect acute spinal cord compression from Cauda Equina Syndrome. It may also be appropriate to discuss a case where outpatient management has failed and the patient is having persistent, disabling deficits.

What happened to this patient?

Despite the large disc herniation, this patient did well non-operatively. He lost weight and did 14 weeks of physical therapy. His paresthesias, pain and motor deficits gradually resolved, and he was able to return to golf and recreational sports at 1 year.