Piriformis syndrome

• Deep gluteal syndrome
• Fat wallet syndrome
• Wallet sciatica
• Sciatic nerve impingement with (out) inflammation
• Hip lateral rotator tendinitis
• Hip lateral rotator tendinosis
• Pseudosciatica

• 355.0 Lesion of sciatic nerve

• G57.00 Lesion of sciatic nerve, unspecified lower limb

• 4E: Impaired Joint Mobility, Motor Function, Muscle Performance, and ROM Associated With Localized Inflammation

Description

• Neuropathic pain from compression of the sciatic nerve as it courses through the piriformis muscle or myofascial pain from a tight, hypertrophic, and tender piriformis without nerve entrapment
• Major muscles at the posterior hip function together based on how much the hip is flexed
  • gluteals
  • piriformis
  • gemelli
  • obturator internus
  • quadratus femoris
• These muscles are usually involved whenever there is low back pain or a lower extremity problem that requires compensation of motion
• The sciatic nerve may even pass through the piriformis (17% of an assumed normal population)

Essentials of Diagnosis

• Diagnosis is usually made by patient history and clinical exam
• Most often an independent diagnosis and not associated with disease process
• May be an independent diagnosis or associated with other musculoskeletal and/or postural disorders
• Must be isolated from gluteus medius, other hip lateral rotators, and sciatic nerve impingement

General Considerations

• Anatomic variations of the divisions of the sciatic nerve above, below, and through the belly of the piriformis muscle may be causative factors
• The piriformis is routinely implicated in cases of sciatica, although it is only one of several muscles in this area that cause sciatica

Demographics

• Higher incidence in females (6:1)
• Increased incidence with
  • Prolonged sitting (occupational, driving, flying, etc. for long periods)
  • Activities requiring extensive and repetitive lateral hip rotation
  • Compensatory foot biomechanics (increased locomotor pronation)
  • Athletes
    • Skiers (Classic Nordic or skate skiing)
    • Long-distance cyclists
    • Tennis players
  • Spinal stenosis (can lead to bilateral piriformis tenderness)
  • Shortened sacrotuberous and or sacrospinous/iliolumbar ligaments
  • Trauma to the buttocks or gluteal region
  • Pregnancy
  • Postural changes
  • Increased weight
  • Change in foot biomechanics during ambulation

Signs and Symptoms

• Pain and instability is often imprecise, but often present in the hip, coccyx, buttock, groin, or distal part of the affected leg
• Tingling/numbness in affected buttock: may be present with sitting on the toilet, bleachers, or narrow bicycle seat
• Pain with forced hip external rotation

Functional Implications

• Pain on ambulation/running with uncompensated pronation
• Increased pain with increased activity or prolonged sitting

Possible Contributing Causes

• Accessory piriformis muscle fibers
• Attachment of the piriformis to the sacrotuberous ligament
• Hypertrophy of the piriformis
• Muscle imbalance of strength and flexibility of hip internal rotators and external rotators
• Obturator internus dysfunction
• Trauma
• Anatomical anomalies

Differential Diagnoses

• Spinal disc herniation
• Gluteal/hip pain
• Sacroiliitis
• Spinal stenosis...