Summary
Sciatica is pain radiating from the buttock down the lower extremity that is caused by compression or injury to the sciatic nerve. It is the most common form of lumbosacral radiculopathy, usually resulting from a herniated disc or spinal stenosis in the low lumbar spine. Characteristic features of sciatica include burning, stabbing, or aching pain, which may be accompanied by weakness and numbness in the lower extremity. Diagnosis is usually clinical, supported by findings from maneuvers such as the straight leg test. Imaging may be considered if there are red flags for acute back pain, diagnostic uncertainty, or refractory symptoms. The majority of cases are self-limiting, with symptoms resolving within three months; conservative management can be used for symptom control but supporting evidence for most interventions is weak. Surgery is reserved for patients with severe or refractory sciatica and clear abnormalities seen on imaging.
Epidemiology
- Lifetime incidence: up to ∼ 40% [1]
- Most often occurs between 30 and 50 years of age [1]
Epidemiological data refers to the US, unless otherwise specified.
Etiology
Sciatica is caused by compression or injury of the sciatic nerve anywhere from its origin at the lumbosacral plexus to the apex of the popliteal fossa where it bifurcates into the tibial and fibular nerves. [1]
Spinal causes of sciatica [1]
Spinal causes are the most common etiology of sciatica.
-
Degenerative disc disease (e.g., intervertebral disc herniation)
- Most commonly affected intervertebral discs: L4–L5 and L5–S1
- Less commonly affected intervertebral discs: L3–L4
- Spondylolisthesis or lumbar spinal stenosis (e.g., due to spinal osteoarthritis)
- Mass effect (e.g., neurofibroma, arachnoid cyst, facet joint synovial cyst)
- Inflammation of the arachnoid mater [2]
Nonspinal causes of sciatica [1]
-
Musculoskeletal
- Piriformis syndrome
- Hip fracture or hip dislocation
- Injury to the hamstrings
- Neuropathic
-
Gynecologic/obstetric
- Endometriosis
- Ovarian cyst and/or uterine enlargement during pregnancy
- Prolonged lithotomy position (e.g., during labor)
-
Other
- Lumbosacral plexitis
- Vascular impingement
- Pressure neuropathy
- Iatrogenic (e.g., gluteal injection site injury)
Clinical features
-
Pain radiating from the buttock down the leg [1]
- Aching, burning, and/or sharp in nature
- Often unilateral
- Onset may be acute or gradual.
- Additional clinical features depend on the cause and location of nerve compression or injury and may include: [1]
- Low back pain
- Paresthesias, numbness, and/or weakness [3]
- Clinical features of lumbosacral radiculopathy
- Clinical features of degenerative disc disease
- Clinical features of spinal stenosis
Diagnosis
This section provides an overview of diagnostics for sciatica. See “Management of acute back pain” for a more comprehensive diagnostic approach.
Approach [1]
- Make the clinical diagnosis of sciatica based on:
- History and physical examination findings of characteristic clinical features
- Signs of nerve root irritation on provocative maneuvers for lumbosacral radiculopathy (e.g., positive straight leg raise test) [1]
- Obtain imaging for patients with red flags for back pain or persistent symptoms.
- If there is diagnostic uncertainty, consider electrodiagnostic studies to help identify the location of nerve root compression. [1][4]
In acute settings, imaging is not routinely indicated for individuals with characteristic clinical features of sciatica and no red flags for back pain. [5]
Imaging [1][5]
Indications
- Indications for imaging in back pain
- Persistent severe symptoms after 6–8 weeks of conservative management: [3]
- To identify the underlying cause of sciatica
- To prepare for surgery or other intervention
Modalities
- Patients with suspected spinal etiology of sciatica
- Preferred: MRI lumbar spine without IV contrast [5]
- Alternatives
- CT myelography: if there are contraindications to MRI
- CT lumbar spine: to assess bones prior to surgery
- X-ray lumbar spine: may be used for surgical planning, evaluation of patients with prior spinal surgery, and/or if a fracture is suspected
- See also “Imaging for back pain.”
- Patients with suspected nonspinal etiology of sciatica
Findings
- May reveal the underlying cause of sciatica (e.g., spinal stenosis, degenerative disc disease)
- Minor abnormalities on imaging (e.g., bulging disc) are common and not likely to be the cause of sciatica. [1]
Differential diagnoses
The differential diagnoses listed here are not exhaustive.
Treatment
Approach [1]
- Advise patients that sciatica usually resolves within 3 months without any intervention. [1]
- Initial management for most patients includes conservative management to improve pain and functioning, despite a paucity of evidence. [1]
- For patients with severe or refractory symptoms, consider:
- Imaging to identify and treat the underlying etiology of sciatica
- Referral to a spine specialist to assess whether surgery is indicated
Approx. 25% of individuals with sciatica have refractory pain for longer than one year. [6]
Conservative management [1][7]
Treatment strategies for sciatica are similar to conservative treatment for nonspecific low back pain, although there is limited evidence supporting their use for sciatica; use shared decision-making to review the risks and benefits.
- Exercise and/or physical therapy [1][6][8]
- NSAIDs (see “Pain management” for dosages) [1][9]
- Oral corticosteroids: Short courses may provide some benefit in patients with disc herniation. [10]
- Epidural corticosteroids: may provide short-term pain relief in patients with persistent symptoms [11]
- Other treatment modalities with little supporting evidence include: [1][7]
Opioids and adjuvant analgesia are not routinely recommended for treating sciatica. [1]
Rest rather than continued activity has not been shown to improve sciatica symptoms. [7]
Surgery [6]
- Indications: severe or refractory symptoms evidenced by imaging findings [6]
-
Modalities: chosen based on the underlying cause of sciatica [1]
- Degenerative disc disease: discectomy [6]
- Spinal stenosis: laminectomy [1][12]
Patients who undergo surgery rather than conservative management have faster resolution of pain, but generally no difference in long-term pain or disability. [1]