Nerve Entrapments in the Hip Region

Nerve entrapments in the hip and pelvic region can be a significant source of pain and dysfunction. The sciatic, pudendal, obturator, femoral and lateral femoral cutaneous nerves are particularly susceptible to compression due to anatomical structures, muscle tightness or trauma.

 

Posterior Nerve Entrapments

Sciatic and Pudendal Nerve Entrapments

The sciatic nerve is vulnerable to compression in multiple locations, including:

• Subgluteal space - entrapment occurs as the sciatic nerve passes under the piriformis muscle and over the obturator internus, gemelli and quadratus femoris.
• Ischiofemoral impingement - the nerve is compressed between the ischium and lesser trochanter, often causing pain during walking.
• Ischial tunnel syndrome - the proximal hamstring tendon can thicken due to trauma, entrapping the sciatic nerve.

The pudendal nerve can become entrapped as it exits the greater sciatic foramen, travels over the sacrospinous ligament and passes through Alcock’s canal. Common sites of entrapment include:

• Between the sacrospinous and sacrotuberous ligaments
• Medial to the ischium, near the obturator internus muscle

 

Symptoms of Posterior Nerve Entrapments

• Sciatic nerve entrapment - buttock pain with radiation down the leg, worsened by sitting or running.
• Ischiofemoral impingement - pain during gait transition from mid-stance to terminal stance.
• Pudendal nerve entrapment - perineal pain worsened by sitting. Cyclists are particularly at risk due to prolonged compression.

 

Diagnostic Tests

• Seated palpation test - helps localize tenderness to different entrapment sites.
• Seated piriformis stretch & active piriformis test - high sensitivity and specificity for sciatic nerve entrapment.
• Ischiofemoral impingement test - hip extension in adducted and externally rotated position reproduces symptoms.
• Active knee flexion test (30° and 90°) - identifies proximal hamstring pathology and ischial tunnel syndrome.

 

Anterior Nerve Entrapments

Obturator, Femoral and Lateral Femoral Cutaneous Nerve Entrapments

The obturator, femoral and lateral femoral cutaneous nerves can also be entrapped, leading to anterior hip pain.

• Obturator nerve - entrapped in the obturator canal or beneath adductor fascia, causing medial thigh pain.
• Femoral nerve - compressed at the inguinal ligament, iliacus compartment or adductor canal, leading to quadriceps weakness and anterior thigh pain.
• Lateral femoral cutaneous nerve - compressed at the inguinal ligament (2 cm medial to ASIS), causing burning pain and numbness in the lateral thigh (MeralgiaParesthetica).

 

Symptoms of Anterior Nerve Entrapments

• Obturator nerve entrapment - medial thigh pain with hip abduction and extension, but not with resisted adduction.
• Femoral nerve entrapment - quadriceps weakness, patellar reflex changes and anterior thigh pain worsened by hip extension and knee flexion.
• Lateral femoral cutaneous nerve entrapment - burning pain, hypersensitivity and numbness in the lateral thigh. It is common in gymnasts and scuba divers.

 

Diagnostic Tests

• Pelvic compression test and Tinel’s sign - identifies lateral femoral cutaneous nerve entrapment with high sensitivity and specificity.
• Modified Thomas test - reproduces femoral nerve symptoms with hip extension and knee flexion.

 

Treatment Approaches

Conservative Management

Most cases of nerve entrapment can be managed non-surgically using a combination of:

• Neural Mobilization - sciatic nerve gliding involves hip flexion, knee extensio and ankle dorsiflexion. Femoral nerve mobilization involves hip extension and knee flexion.
• Soft-Tissue Mobilization - techniques like deep friction massage, effleurage and instrument-assisted therapy may help release nerve adhesions.
• Stretching and Strengthening - must be slow and progressive to avoid further irritation. Strengthening focuses on pelvic stability & lower limb biomechanics.
• Aerobic Exercise and Cognitive Behavioral Therapy - beneficial for chronic nerve pain management.

 

Surgical Management

If conservative treatment fails, surgical options include:

• Neurolysis - surgical decompression to remove adhesions or anatomical impingements.
• Neurectomy - resection of the affected nerve, often used in cases of chronic pain with high recurrence risk.

Example - Neurectomy is more effective than neurolysis for treating Meralgia Paresthetica.

Many procedures that were traditionally performed as open surgeries are now done arthroscopically, allowing for faster recovery and fewer complications.