Sciatica (sciatic nerve)

Anatomy: course and function of the sciatic nerve

The sciatic nerve is the strongest nerve in the body. It arises from nerve fibers from segments L4 to S3, leaves the pelvis through the greater sciatic foramen, usually below the piriformis muscle, runs deep in the buttocks through the so-called deep gluteal space and extends distally on the back of the thigh. At the level of the popliteal fossa it divides into the tibial nerve and the common peroneal nerve. The close proximity to the piriformis, quadratus femoris, the short external rotators and the proximal hamstring insertion explains why constriction and irritation can occur there.

• Motor function: Supply of large parts of the thigh and lower leg muscles via its terminal branches
• Sensitivity: Posterior thigh, lower leg and foot areas depending on the end branch
• Typical pain path: buttocks → back of thigh → lower leg/foot

If the nerve is irritated mechanically or inflammatoryly, burning, electrifying pain, abnormal sensations and, if the damage is severe, muscle weakness occur.

Typical symptoms of sciatica

• Stinging or burning pain from the buttocks into the leg, sometimes even into the foot
• Tingling, pins and needles, numbness along the back of the thigh
• Reinforcement when sitting, bending, driving for long periods or when coughing/sneezing
• Tenderness deep in the buttocks, pain when getting up from sitting
• Stress-related weakness, e.g. E.g. lifting the foot or standing on the toes depending on the nerve branch
• Pain at night making it difficult to lie on your side; Relief through changing positions

It is important to differentiate: lumbar nerve root irritation (e.g. in the case of intervertebral disc prolapse) often shows a positive Lasègue test and segment-typical failures. Peripheral sciatic nerve compression in the buttocks is more likely to show local tenderness, sitting intolerance, pain when contracting the external rotators, and specific provocation tests for the deep gluteal space.

Causes: From intervertebral disc to deep gluteal syndrome

Sciatica is a collective term – the triggers are varied. Common causes in the hips and pelvis are tightness in the deep gluteal space, muscular imbalances or irritation at the origin of the hamstring. Changes in the lumbar spine can also cause similar pain.

• Deep gluteal syndrome: Functional or anatomical narrowing of the sciatic nerve beneath the piriformis and short external rotators
• Piriformis syndrome: Muscle spasm or hypertrophy irritates the nerve
• Proximal hamstring tendinopathy or partial tear with scarring proximity to the sciatica
• Post-injection neuropathy in the buttocks, rarely after intramuscular injections
• Scars, connective tissue bands or vascular loops in the sciatic canal
• Trauma or fractures of the pelvis, sciatic avosions during sports
• Lumbar radiculopathy due to herniated disc, spinal canal stenosis
• Rare causes: tumors/cysts, sciatic endometriosis, heterotopic ossification

Everyday factors can also contribute, such as sitting for long periods of time, sitting on a hard edge, having a large wallet in your back pocket, or exercising without sufficient hip mobility.

Diagnostics: Thorough, differentiated and targeted

It starts with a detailed anamnesis and a structured physical examination. We check the mobility of the hips, pelvis and lumbar spine, carry out neurological tests and specific provocation maneuvers and specifically palpate the deep gluteal space.

• Neurological tests: strength, reflexes, sensitivity; Lasègue and Slump test
• Specific tests: FAIR, Freiberg, Pace, FADIR and palpation along the course of the nerve
• Functional test: hip external rotators, abductors and hamstrings
• Gait analysis, posture and ergonomics check

We use imaging according to indications. If lumbar radiculopathy is suspected, MRI of the lumbar spine is helpful. In the case of peripheral sciatica irritation, MRI of the pelvis/hip is recommended, if necessary with MR neurography to show constrictions, scars or muscle-tendon changes.

• MRI lumbar spine and pelvis/hips depending on the question
• High-resolution ultrasound for dynamic assessment, injection planning
• EMG/nerve conduction velocity for objectification of motor deficits
• Diagnostic injections with local anesthetic to identify the source of pain

Warning signs such as rapidly increasing weakness, foot dorsiflexion, bladder/rectum disorders or numbness in the breeches area are emergencies and require immediate clarification.

Conservative therapy: gradual, active and close to everyday life

Conservative measures are in the foreground. They combine education, adapted activity, physiotherapy and time-limited drug pain therapy. The aim is to calm nerve irritation, improve the quality of movement and build resilience.

• Education and activity adjustment: Short sitting intervals, changing positions, no heavy lifting in acute phases
• Physiotherapy: Neurodynamic nerve mobilization, piriformis/external rotator stretching, progressive glute and hip stabilizer strengthening
• Load management hamstrings: Gradual eccentricity program with tendon involvement
• Manual techniques and myofascial treatment for tone regulation
• Ergonomics: workplace, driving position, sports technology and footwear
• Heat or cold depending on tolerance for pain modulation

Medication can relieve symptoms in the acute phase. Depending on individual tolerance, these include anti-inflammatory preparations and analgesics. If neuropathic pain is severe, adjuvant substances may also be considered in consultation with your family doctor. Long-term, long-term medication without benefit is avoided.

Important: move again early, but in doses. Complete protection often leads to longer courses. Exercises are individually adapted and usually increased over several weeks.

Targeted injections and regenerative options

If basic conservative measures are not sufficient or to confirm the diagnosis, we can consider image-guided injections. They are intended to reduce pain and make rehabilitation easier. The procedure is carried out carefully, adapted to the anatomy and not into the nerve.

• Ultrasound or MRI-guided perineural injection near the sciatica with local anesthetic, if necessary low-dose corticoid
• Infiltration of trigger points in the piriformis/short external rotators
• In proximal hamstring tendinopathy: tendon edge infiltration; Regenerative procedures such as PRP are considered based on strict indications; the evidence is moderate and heterogeneous
• Hydrodissection with saline or dextrose to improve lubrication is a possible procedure with still limited evidence

Risks and side effects such as temporary numbness, bleeding, infection or steroid-related effects are discussed in advance. Injections do not replace active therapy, but rather accompany it.

Surgery: Rare indication, clear criteria

Surgical interventions are rarely necessary. They come into consideration in the case of progressive motor weakness, proven structural constriction with significant loss of function or persistent severe symptoms despite consistent conservative therapy for months.

• Decompression of the deep gluteal space, endoscopic or open
• Release of cicatricial adhesions on the sciatica, piriformis release
• Treatment of masses or reconstruction of hamstring avulsion

In our practice, the focus is on conservative orthopedics. If there is a clear indication for surgery, we will coordinate further clarification and, if requested, establish contact with experienced partner centers in Hamburg and supervise follow-up treatment.

Self-help and prevention in everyday life

• Sitting hygiene: Get up every 30-45 minutes, walk briefly, stretch your hips
• Do not carry your wallet in your back pocket; use a soft seat
• Mobility: Gentle piriformis and hip flexor stretches, 2-3 sets daily
• Neurodynamic exercises in a pain-free range, regularly but moderately
• Strength training: gluteus medius and maximus, core stability, eccentric hamstrings
• Sport: Increase the load slowly, train your technique, warm up adequately
• Regeneration: Sleep, stress management, low-inflammatory diet support the process

Individual exercise programs are adapted to findings and everyday life. Intensifying too quickly can increase irritation - the right dose is crucial.

Course and prognosis

Many sciatica symptoms improve within weeks with conservative treatment. Depending on the cause, recovery time can be 6-12 weeks or longer. Neuropathic sensations often subside more slowly than movement pain.

• Favorable: Early, measured activity and targeted physiotherapy
• Prolonging: Prolonged sitting, inappropriate training load, smoking and untreated comorbidities
• Regular follow-up checks help to adjust therapy and stress

Complete freedom from symptoms cannot be guaranteed. However, in most cases functional ability can be significantly improved if the treatment is structured and everyday factors are taken into account.

When to go to the doctor, when to act immediately

• Severe or increasing weakness in the leg, unable to lift the foot or stand on tiptoe
• Bladder or rectal disorders, numbness in the genital and sitting areas
• Fever, severe pain at night when resting, unintentional weight loss
• Fall or trauma with persistent pain in the pelvis or buttocks
• Diabetes, known tumor disease, immunosuppression or long-term cortisone therapy

If you see such warning signs, please seek medical advice immediately. For all other sciatica complaints, we recommend a prompt but calm diagnosis and a conservative treatment plan.

Differential diagnoses: What feels similar

• Lumbar radiculopathy L5/S1 due to intervertebral disc or spinal canal stenosis
• Sacroiliac joint dysfunction with buttock pain
• Trochanteric pain syndrome, gluteal tendinopathy
• Proximal hamstring tendinopathy without nerve involvement
• Meralgia paraesthetica with burning pain on the front of the thigh
• Peroneal neuropathy of the fibular head as a cause of dorsiflexor weakness

The distinction is made through targeted examination, appropriate imaging and, if necessary, diagnostic infiltrations.