The sural nerve
The sural nerve is exposed during surgical treatment of certain conditions affecting the ankle and hindfoot. It must be identified during surgical procedures involving the calcaneus, the Achilles tendon, or the fibular tendons.
Anatomy and function of the sural nerve
The sural nerve is formed by the union of the medial sural cutaneous nerve and the lateral sural cutaneous nerve. It runs along the posterior and lateral part of the leg with the small saphenous vein. Its function is limited to transmitting sensory information to areas such as the posterolateral surface of the distal third of the leg, the heel, and the lateral side of the foot. It is an important landmark during surgical procedures.
Common causes of irritation or injury to the sural nerve
Sural nerve disorders can have various causes:
- Direct injuries or ankle sprains
- Scar-related compression after surgery on the Achilles tendon, the calcaneus, or the fibular tendons.
- Cysts or benign tumors exerting pressure on the nerve
- Sports overuse causing stretching or inflammation
- Iatrogenic lesions during surgical procedures or local injections
Identifying the exact cause is essential to determine the appropriate therapeutic strategy.
Symptoms and indications
Signs of irritation or compression of this nerve include:
- Pain with burning sensations or feeling of electric shocks
- Numbness, localized paresthesias in the nerve’s territory
- Increased sensitivity to touch over the innervated area
- Discomfort that intensifies when walking or during prolonged standing
These symptoms may occur as part of a canal syndrome, a neuroma of the sural nerve, or in cases of repeated trauma and mechanical stress. A consultation is necessary when these symptoms disrupt daily life.
Diagnosis and therapeutic management
The diagnosis is based on a thorough clinical examination including palpation with the Tinel test, and the search for scars near the sural nerve. Additional tests, such as ultrasound and electromyography, make it possible to better visualize the nerve pathway and confirm nerve compression or damage.
MRI is less precise than ultrasound for nerve analysis due to its small size.
Conservative treatment and surgical treatment
Depending on the nature and intensity of the symptoms, treatment may be conservative or surgical. Conservative treatment is based on the use of suitable foot orthoses and on modifying footwear to reduce pressure on the painful area. Physiotherapy also plays a vital role, thanks to specific stretching and strengthening protocols. Additionally, corticosteroid or anti-inflammatory injections may be administered to reduce inflammation and relieve symptoms.
When these measures prove insufficient, surgical management may be considered. This may involve nerve decompression performed using minimally invasive techniques or, in cases of persistent neuroma, a neurectomy. Percutaneous techniques can also be used to avoid making too large an incision along the nerve’s entire path.
The surgical technique
The procedure requires planning. Ultrasound is always performed preoperatively to look for a neuroma of the sural nerve.
In the absence of a neuroma, nerve release is considered, which consists of a neurolysis. In the case of a neuroma, the nerve is damaged and the procedure involves resecting the sural nerve, which is referred to as a neurectomy.
The goal is to perform the neurolysis through a reasonable incision, centered over the compressed area of the nerve. Retractors help to increase the operative field, and the use of a surgical spatula allows for comprehensive release of the nerve, subcutaneously, without increasing the size of the incision.
The neurectomy must address the injured portion of the nerve previously identified by ultrasound. The incision is therefore precisely centered over the neuroma.
Precision of the minimally invasive surgical procedure
Several measures help to limit tissue dissection:
- High-definition ultrasound to precisely visualize the nerve and surrounding tissues
- Minimally invasive instruments allowing for gentle intervention
- Intraoperative imaging systems for optimal guidance of surgical gestures
Prevention and Therapeutic Follow-up
After treatment, it is important to regain calf flexibility through regular stretching exercises of the posterior muscle chains. The choice of shoes also plays a key role: they should be suited to the shape of the foot, provide good support, and reduce friction on the sensitive lateral area.
Rehabilitation, supervised by a physiotherapist, aims to restore joint stability and muscle strength.
Resuming sports activities should be done gradually and under medical supervision.
FAQ about the sural nerve and management
They include burning pain, numbness, tingling, and hypersensitivity to touch on the lateral side of the ankle and foot.
The diagnosis is based on the clinical examination, performing the Tinel test, ultrasound and electromyography.
Surgery is considered when conservative treatments (insoles, physiotherapy, injections, footwear adjustments) do not provide lasting relief. If the pain persists and interferes with daily activities, minimally invasive nerve decompression or a neurectomy may be suggested.
Recovery is generally quick thanks to minimally invasive techniques. Gentle rehabilitation begins quickly after the procedure, and the gradual resumption of activities takes place over a few weeks.