The sural nerve (SN) is a sensory nerve that supplies the outer side of the lower leg, ankle, and foot. It transmits sensations such as touch, temperature, and pain from these regions to the brain. Because it lies close to the surface of the skin, it is more vulnerable to irritation or compression than deeper nerves. When the sural nerve becomes compressed or irritated, the condition is known as sural nerve entrapment — a source of chronic lateral foot and ankle pain that can significantly affect daily comfort and mobility.
How Common It Is and Who Gets It? (Epidemiology)
Sural nerve entrapment is an uncommon but underdiagnosed condition. It can affect adults of all ages, particularly athletes, runners, and individuals who wear tight footwear or engage in repetitive ankle movement. It can also develop after ankle sprains, fractures, or surgical procedures in the lower leg. Both men and women are affected equally, though the condition is more prevalent in people with prior ankle injuries or chronic swelling.
Why It Happens – Causes (Etiology and Pathophysiology)
The sural nerve can become compressed or injured by several mechanisms, including:
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Anatomical variations: Some people have additional nerve branches or tight fascial tunnels that increase compression risk.
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Repetitive motion or overuse: Running, cycling, or prolonged walking on uneven surfaces can irritate the nerve.
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Trauma or scarring: Direct injury, fracture, or surgical scarring near the lateral ankle or calf may entrap the nerve.
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External pressure: Tight footwear, ankle braces, or casts can compress the nerve.
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Postoperative changes: The nerve may become trapped in scar tissue following previous ankle or Achilles tendon surgery.
When the sural nerve is compressed, sensory signals are disrupted, leading to pain and altered sensation along its pathway.
How the Body Part Normally Works? (Relevant Anatomy)
The sural nerve originates from branches of the tibial and common peroneal nerves in the lower leg. It runs down the back of the calf, travels behind the lateral malleolus (outer ankle bone), and extends to the outer foot. The nerve carries only sensory fibers — it does not control muscles — making it responsible for sensations such as pain, temperature, and light touch on the lateral side of the foot.
What You Might Feel – Symptoms (Clinical Presentation)
Typical symptoms include:
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Burning, tingling, or sharp pain along the outer side of the leg and foot.
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Numbness or pins-and-needles sensation in the lateral ankle and foot.
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Tenderness when pressure is applied near the lateral malleolus or along the nerve’s path.
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Pain exacerbated by movement (especially ankle inversion or plantar flexion).
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Hypersensitivity to touch or even mild pressure.
Motor weakness is rare since the sural nerve is purely sensory.
How Doctors Find the Problem? (Diagnosis and Imaging)
Diagnosis begins with a detailed clinical evaluation and is supported by diagnostic testing:
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Physical Exam: Palpation along the nerve’s course to identify tenderness or a positive Tinel’s sign (tingling when the nerve is tapped).
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Imaging: MRI or ultrasound to visualize nerve compression by scar tissue, fascia, or cysts.
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Nerve Conduction Studies (NCS): Assess nerve function and detect reduced sensory response in the sural nerve distribution.
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Diagnostic Nerve Block: Injection of local anesthetic near the nerve can temporarily relieve symptoms, confirming the diagnosis.
Classification
Sural nerve entrapment is classified by cause or site:
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Proximal entrapment: Compression within the calf fascia.
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Distal entrapment: Compression behind the lateral malleolus or along the outer foot.
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Post-traumatic entrapment: Following injury or surgery with scar formation.
Other Problems That Can Feel Similar (Differential Diagnosis)
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L5 or S1 radiculopathy (nerve root compression in the spine)
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Peroneal nerve entrapment
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Achilles tendinitis or bursitis
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Complex regional pain syndrome (CRPS)
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Morton’s neuroma
Treatment Options
Non-Surgical Care
Initial management focuses on relieving compression and inflammation:
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Rest and Activity Modification: Avoid activities that worsen symptoms.
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Footwear Adjustment: Use shoes with wider heels or softer padding.
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NSAIDs: Medications like ibuprofen reduce inflammation and pain.
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Physical Therapy: Stretching, massage, and nerve gliding techniques may improve mobility.
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Orthotic Support: Insoles can redistribute pressure and reduce nerve irritation.
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Nerve Blocks: Local anesthetic injections can provide temporary pain relief and confirm the diagnosis.
Surgical Care
If conservative care fails after several months, surgical neurolysis or excision may be recommended.
Procedure: Excision or Decompression (CPT 64708)
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Anesthesia and Incision: The procedure is performed under local or regional anesthesia. A small incision is made along the nerve path.
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Decompression (Neurolysis): The surgeon carefully releases the nerve from surrounding fibrous bands, fascia, or scar tissue.
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Excision (If Necessary): Severely damaged nerve segments or neuromas (painful scarred nerves) are excised.
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Closure: The incision is closed with fine sutures, and a dressing or protective boot is applied.
Duration: The surgery usually takes 30–60 minutes and can be performed as an outpatient procedure.
Recovery and What to Expect After Treatment
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Initial Care: Keep the incision clean and dry for 1–2 weeks.
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Weight-Bearing: Light walking may resume within a few days; avoid excessive activity for 3–4 weeks.
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Physical Therapy: Recommended to improve strength, mobility, and sensory recovery.
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Full Recovery: Typically achieved within 6–8 weeks, although mild numbness may persist temporarily.
Most patients report marked improvement in pain and sensitivity once the nerve is decompressed.
Possible Risks or Side Effects (Complications)
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Infection or delayed wound healing
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Persistent numbness or tingling
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Nerve injury leading to residual pain (neuroma formation)
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Recurrence of symptoms due to scar tissue
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Rarely, hypersensitivity or chronic regional pain syndrome
Long-Term Outlook (Prognosis)
Sural nerve decompression or excision offers excellent outcomes, with success rates exceeding 80% in most series. Pain reduction and sensory improvement are typical within weeks, and permanent deficits are rare. Proper surgical technique and careful postoperative rehabilitation minimize recurrence or persistent pain.
Out-of-Pocket Cost
Medicare
CPT Code 64708 – Excision or Decompression of Sural Nerve (Neuroplasty, Major Peripheral Nerve): $119.08
Medicare Part B typically covers 80% of the approved cost for this procedure once your annual deductible has been met, leaving you responsible for the remaining 20%. Supplemental Insurance plans such as Medigap, AARP, or Blue Cross Blue Shield usually cover that remaining 20%, minimizing or eliminating out-of-pocket expenses for Medicare-approved procedures. These plans coordinate with Medicare to fill the coverage gap and lower your overall financial responsibility.
If you have Secondary Insurance such as TRICARE, an Employer-Based Plan, or Veterans Health Administration coverage, it serves as a secondary payer. These plans often cover any remaining coinsurance or small deductibles, which typically range between $100 and $300, depending on your plan and provider network.
Workers’ Compensation
If your sural nerve compression or injury occurred as a result of a work-related activity, Workers’ Compensation will cover all medical expenses, including the decompression procedure, rehabilitation, and postoperative care. You will not have any out-of-pocket costs, as your employer’s insurance carrier directly pays for all approved treatments.
No-Fault Insurance
If your sural nerve injury resulted from an automobile accident, No-Fault Insurance will typically cover the full cost of your treatment, including the nerve decompression procedure and recovery. The only potential out-of-pocket expense may be a small deductible or co-payment based on your insurance policy.
Example
Thomas Rivera experienced chronic pain and numbness due to sural nerve compression and underwent nerve decompression (CPT 64708). His estimated Medicare out-of-pocket cost was $119.08. Since Thomas had supplemental insurance through AARP Medigap, his remaining balance was fully covered, leaving him with no out-of-pocket expenses for the procedure.
Frequently Asked Questions (FAQ)
Q. What is Sural Nerve Entrapment?
A. Sural nerve entrapment occurs when the sural nerve, which runs along the outside of the lower leg and foot, becomes compressed or irritated, leading to pain, numbness, and tingling in the affected areas.
Q. What causes Sural Nerve Entrapment?
A. Sural nerve entrapment can result from anatomical variations, repetitive motion (such as running), trauma or injury to the lower leg, or external pressure from tight footwear or excessive ankle inversion.
Q. How is Sural Nerve Entrapment diagnosed?
A. Diagnosis typically includes a physical exam, nerve conduction studies, and imaging tests such as MRI or ultrasound to locate the compression and assess the extent of the nerve irritation.
Q. What are the symptoms of Sural Nerve Entrapment?
A. Symptoms include pain along the outer side of the lower leg, tingling or numbness in the foot, increased sensitivity to touch, and sometimes weakness when standing or walking.
Q. What is the treatment for Sural Nerve Entrapment?
A. Conservative treatments include rest, physical therapy, anti-inflammatory medications, and changes in footwear. In severe cases, surgical options like neurolysis or excision of compressive structures may be necessary.
Q. How effective is surgery for Sural Nerve Entrapment?
A. Surgery is highly effective in relieving symptoms for most patients, with significant pain reduction and restoration of nerve function, especially when non-surgical treatments fail.
Q. What is the recovery process after Sural Nerve Decompression surgery?
A. Recovery includes wearing a protective dressing, avoiding weight-bearing for a short period, followed by physical therapy to restore strength and mobility. Full recovery typically takes a few months.
Q. Are there risks associated with Sural Nerve Decompression surgery?
A. Risks include infection, nerve injury, or recurrence of symptoms. However, these complications are rare, and the procedure is generally safe when performed correctly.
Q. How long does the Sural Nerve Decompression surgery take?
A. The procedure typically takes about 30 to 60 minutes, depending on the complexity of the compression and the surgical approach used.
Q. Can the Sural Nerve Decompression procedure be done on both legs at the same time?
A. While it is possible, it is generally recommended to perform the procedure on one leg at a time to allow for proper healing and reduce the risk of complications.
Q. Will I need to wear a cast or boot after Sural Nerve Decompression surgery?
A. You may need to wear a special boot or brace to protect the foot and ankle after surgery, particularly during the initial recovery period, which typically lasts a few weeks.
Q. What is the success rate of Sural Nerve Decompression surgery?
A. The surgery is highly successful, with most patients experiencing significant relief from pain, improved sensation, and better function in the affected foot and leg. Success rates are generally above 80%.
Q. Will I experience any numbness after Sural Nerve Decompression surgery?
A. Some patients may experience temporary numbness or altered sensation in the affected foot or leg during recovery, but this usually resolves as the nerve heals. Permanent numbness is rare.
Q. Can Sural Nerve Decompression surgery be combined with other foot or ankle procedures?
A. Yes, Sural Nerve Decompression can be combined with other surgeries, such as tendon repairs or joint procedures, if necessary, to address other foot or ankle conditions at the same time.
Q. How soon can I return to work after Sural Nerve Decompression surgery?
A. Most patients can return to work within 1 to 2 weeks if their job is sedentary. For more physically demanding work, full recovery may take 4 to 6 weeks, depending on the healing process.
Q. What is sural nerve entrapment?
A. It’s compression or irritation of the sensory nerve on the outer lower leg and foot, causing pain, tingling, or numbness.
Q. Can sural nerve entrapment heal without surgery?
A. Yes. Many cases improve with rest, physical therapy, and footwear changes. Surgery is only needed when conservative care fails.
Q. What does sural nerve decompression surgery involve?
A. The surgeon releases the nerve from tight tissue or scar bands, relieving pressure and restoring normal sensation.
Q. Is surgery painful?
A. Postoperative discomfort is mild and well-managed with medication. Most patients walk comfortably within days.
Q. What is the recovery time?
A. Full recovery generally takes 6–8 weeks, depending on activity level and healing.
Q. Can surgery cause numbness?
A. Temporary numbness is common and resolves with healing. Permanent numbness is rare.
Q. Will I need physical therapy after surgery?
A. Yes. Therapy helps restore flexibility and prevent scar tissue from reforming.
Summary and Takeaway
Sural nerve entrapment is an uncommon but treatable cause of pain and numbness in the lower leg and outer foot. Conservative management helps most patients, but surgical decompression or excision provides lasting relief when symptoms persist. Early diagnosis, careful surgical planning, and structured rehabilitation lead to excellent outcomes and restored comfort.
Clinical Insight & Recent Findings
Recent reports highlight the importance of early diagnosis to prevent chronic pain syndromes. A case study published in the Kawasaki Medical Journal described a 67-year-old patient with persistent lateral foot pain due to sural nerve entrapment who achieved complete pain relief after neurolysis.
Another study from the Aristotle University of Thessaloniki emphasized that anatomical variations and fibrous tunnels around the nerve are key causes of entrapment and that timely decompression prevents long-term neuropathic changes.
Who Performs This Treatment? (Specialists and Team Involved)
Treatment is typically performed by an orthopedic foot and ankle surgeon or peripheral nerve specialist. The care team may include an anesthesiologist, physical therapist, and pain management specialist.
When to See a Specialist?
Consult a specialist if you experience persistent burning pain, numbness, or tingling along the outer ankle or foot that does not improve with rest, medication, or therapy.
When to Go to the Emergency Room?
Seek immediate care if you experience severe pain after trauma, swelling with redness or fever (possible infection), or sudden loss of foot sensation.
What Recovery Really Looks Like?
Recovery involves mild swelling and tenderness at the incision site for a few weeks. Symptoms of numbness or tingling typically improve within weeks, and long-term pain relief is achieved in most cases.
What Happens If You Ignore It?
Untreated sural nerve entrapment can lead to chronic neuropathic pain, sensory loss, or permanent nerve damage. Early treatment prevents these complications and restores normal sensation.
How to Prevent It?
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Wear properly fitted shoes.
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Avoid prolonged external compression on the calf or ankle.
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Stretch and strengthen lower leg muscles to reduce strain.
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Address ankle injuries promptly to prevent scar formation.
Nutrition and Bone or Joint Health
A diet rich in B vitamins (especially B12), omega-3 fatty acids, and antioxidants supports nerve health and recovery. Maintaining hydration and limiting alcohol intake also improve nerve function.
Activity and Lifestyle Modifications
Gradually resume activity after surgery. Choose low-impact exercises such as swimming or cycling and avoid repetitive ankle inversion. Long-term, maintain healthy footwear and incorporate stretching routines to prevent recurrence.
Dr. Mo Athar
