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Piriformis Syndrome G57.00 355.0

ICD-9 Classification / Treatment
Etiology / Epidemiology / Natural History Associated Injuries / Differential Diagnosis
Anatomy Complications
Clinical Evaluation Follow-up Care
Xray / Diagnositc Tests Review References

synonyms: deep gluteal syndrome

Piriformis Syndrome ICD-10

Piriformis Syndrome ICD-9

  • 355.0 (lesion of sciatic nerve)


Piriformis Syndrome Etiology / Epidemiology / Natural History

  • Extrapelvic sciatic sciatic nerve compression in the area of the greater sciatic notch of the pelvis.
  • Post-traumtic piriformis syndrome is associated with blunt trauma to the buttock

Piriformis Syndrome Anatomy

  • Thought to result from compression of the sciatic nerve, gluteal nerves, posterior femoral cutaneous nerve or pudendal nerve by the piriformis muscle or by obturator internus/gemelli

Piriformis Syndrome Clinical Evaluation

  •  Symptoms are non-specific
  • Pain/dysethesias in gluteal region +/- radiation into hip/posterior thigh/down leg
  • +/- history of trauma
  • May have buttock or thigh pain as only symptom
  • tenderness in sciatic notch
  • Flexion, adduction, and internal rotation exacerbates symptoms
  • palpable tender mass over piriformis if present is pathognomonic (Robinson DR, Am J Surg 1947;73:355)
  • Lasegue's sign: pain in the vacinity of the greater sciatic notch with extension of the knee with the hip flexed to 90 degrees and tenderness to palpation of the greater sciatic notch
  • Frieberg's sign: pain with passive internal rotation of the hip
  • Pace's sign: pain and weakness in association with resisted abduction and external rotation of the affected thigh. (Pace JB, Western J Med 1976;124:435)
  • may have intolerance to sitting

Piriformis Syndrome Xray / Diagnositc Tests

  •  A/P pelvis, A/P and lateral of affected hip will be normal
  • MRI is useful to r/o other diagnoses and should be normal
  • CT may show asymmetrical enlargement of the piriformis muscle. (Jankiewicz, JJ Clin Orthop 1991;262:205)
  • EMG/NCV can document nerve impingement. Often normal at rest, but become abnormal with hip flexion/IR (Fishman L Arch Phys Med Rehabil 1992;73:359)
  • Diagnosis can be confirm by fluoroscopic or electomyographic assisted anesthetic injections immediately alleviating symptoms

Piriformis Syndrome Classification / Treatment

  •  Rest, NSAIDs, muscle relaxants, physical therapy aimed at stretching the piriformis and short external rotators
  • Consider piriformis anesthetic/corticosteroid injection
  • Surgery = sectionoing piriformis at its origin, release of any fibrous bands and external sciatic neurolysis (Benson ER, JBJS 1999;81A:941)

Piriformis Syndrome Associated Injuries / Differential Diagnosis

Piriformis Syndrome Complications

  • Sciatic nerve palsy
  • Vascular injury
  • Infection
  • Hematoma

Piriformis Syndrome Follow-up Care


Piriformis Syndrome Review References

  • Fishman L, Dombi G, Michealsen C, et al: Piriformis syndrome: Diagnosis, treatment, and outcome.  A 10 year study; Arch Phys Med Rehabil 2002;83:295-301





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