Sciatic Nerve Decompression Technique

Updated: Sep 22, 2015
  • Author: Andrew I Elkwood, MD, MBA, FACS; Chief Editor: Jorge E Alvernia, MD  more...
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Technique

Approach Considerations

The sciatic nerve can be compressed proximally near the sciatic notch or more distally in the thigh. There are two different surgical approaches, which can also be combined.

For proximal pathology, a curvilinear incision around the posterolateral aspect of the buttocks is made, which is then carried medially distal to the gluteal fold. The area of the sciatic nerve is in the area of the ischial tuberosity just below the inferior border of the gluteus maximus muscle and between the hamstring muscles.

The gluteus maximus muscle is dissected off the iliotibial tract and the femur and dissected medially. This maneuver exposes the anatomy of the superior and inferior gluteal nerves, as well as the sciatic nerve. Care should be exercised to avoid injury to the perforating vessels.

If these vessels are to be transected, prior proximal control is recommended, as they may retract into the pelvis. At the point of exposure, nerve monitoring and direct observation can be used to discern the cause of the compression. Vascular bands can be ligated and transected. Muscular compression can be released with partial myotomy. Neurolysis can be performed for scarring.

Predissection and postdissection electromyography testing or conduction studies are often helpful in determining prognosis or the need for nerve grafting. If necessary, the tibial and peroneal contributions of the sciatic nerve can be isolated to be dealt with separately. If nerve grafting needs to be performed, sural nerves can be harvested and the microscope brought into the field.

After the nerves are decompressed and hemostasis is achieved, the gluteal muscles are reapproximated with long-term absorbable sutures and a stout suturing technique. A surgical drain may be placed. The skin and subcutis are closed with surgeon preference. Sturdy closure techniques should be used, as the patient will bear weight and flex the area.

When the pathology is further distal, the sciatic nerve is exposed with a near midposterior approach between the biceps femoris muscle and the semitendinosus muscle.. If necessary, muscles can be divided to maximize exposure. Distal to the adductor canal, the popliteal artery and vein are encountered medially and must be treated carefully. Use of an operating sterile tourniquet (at least on standby) can be helpful. The surgeon must also be cognizant of the nerves crossing genicular vessels that may be encountered near the knee joint.

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Other Interventions

Conservative treatment of sciatic nerve compression and piriformis syndrome may include the following:

  • Physical therapy and stretching
  • Injection of corticosteroids and/or local anesthetic into the piriformis muscle, usually performed under image guidance
  • Therapy with systemic medications, such as gabapentin or pregabalin, for neuropathic pain

Other interventions for sciatic neuropathies when proximal nerve exploration and repair is not feasible are usually primarily aimed at overcoming foot drop. These interventions include the following:

  • Use of an orthotic device
  • Tendon transfer from the posterior tibial muscle to the anterior tibial muscle (applicable only in cases of lateral sciatic nerve trunk injury in which the former muscle may be spared)
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