Surgical and Radiologic Anatomy

, Volume 29, Issue 1, pp 37–45 | Cite as

Piriformis muscle: clinical anatomy and consideration of the piriformis Syndrome

  • Gunther Windisch
  • Eva Maria Braun
  • Friedrich Anderhuber
Original Article


Patients with lumbosacral and buttock pain provide tacit support for recognizing the piriformis muscle as a contributing factor to the pain (piriformis syndrome). One hundred and twelve cadaveric specimens were observed to elucidate the anatomical variations of the piriformis muscle referred to the diagnostic and treatment of the piriformis syndrome. The distance between the musculotendinous junction and the insertion was measured and the piriformis categorized into three types: Type A (71, 63.39%): long upper and short lower muscle belly; Type B (40, 35.71%): short upper and long lower muscle belly; Type C (1, 0.9%): fusion of both muscle bellies at the same level. The diameter of the piriformis tendon at the level of the musculotendinous junction ranged from 3 to 9 mm (mean: 6.3 mm). The piriformis showed the following possible fusions with adjacent tendons. In type one (60, 53.57%) a rounded tendon of the piriformis reached the upper border of the greater trochanter. In type two (33, 29.46%) it first joined into the gemellus superior tendon and at last both fused with the obturator internus tendon and inserted into the medial surface of the greater trochanter. A fusion of the piriformis, obturator internus and gluteus medius tendon with the same insertion area as above was observed in type three (15, 13.39%) and finally in type four (4, 3.57%) the tendon fused with the gluteus medius to reach the upper surface of the greater trochanter. Based on this survey anatomical causes for the piriformis syndrome are rare and a more precise workup is necessary to rule out more common diagnosis.


Piriformis Anatomy Piriformis syndrome Piriformis fossa Terminology Sciatic nerve 


  1. 1.
    Babinski MA, Machado FA, Costa WS (2003) A rare variation in the high division of the sciatic nerve surrounding the superior gemellus muscle. Eur J Morphol 41(1):41–42PubMedCrossRefGoogle Scholar
  2. 2.
    Barton PM (1991) Piriformis syndrome: a rational approach to management. Pain 47:345–352PubMedCrossRefGoogle Scholar
  3. 3.
    Beaton LE, Anson JB (1937) The relation of the sciatic nerve and of its subdivisions to the piriformis muscle. Anat Rec 70:1–5CrossRefGoogle Scholar
  4. 4.
    Beatty RA (1994) The piriformis muscle syndrome: a simple diagnostic maneuver. Neurosurgery 34(3):512–514PubMedGoogle Scholar
  5. 5.
    Beauchnese RP, Schutzer SF (1997) Myositis ossificans of the piriformis muscle: an unusual case of piriformis syndrome. A case report. J Bone Joint Surg [Am] 79(6):906–910Google Scholar
  6. 6.
    Benzon HT, Katz JA, Benzon HA, Iqbal MS (2003) Piriformis syndrome. Anesthesiology 98:1442–1448PubMedCrossRefGoogle Scholar
  7. 7.
    Broadhurst NA, Simmons DN, Bond MJ (2004) Piriformis syndrome: correlation of muscle morphology with symptoms and signs. Arch Phys Med Rehabil 85:2036–2039PubMedCrossRefGoogle Scholar
  8. 8.
    Brown JA, Braun MA, Namey TC (1988) Piriformis syndrome in a 10-year old boy as a complication of operation with the patient in the sitting position. Neurosurgery 23:117–119PubMedGoogle Scholar
  9. 9.
    Chen WS (1994) Bipartite piriformis muscle: an unusual cause of sciatic nerve entrapment. Pain 58(2):269–272PubMedCrossRefGoogle Scholar
  10. 10.
    Chen WS (1992) Sciatica due to piriformis pyomyositis. J Bone Joint Surg [Am] 74:1546–1548Google Scholar
  11. 11.
    Fishman LM, Konnoth C, Rozner B (2004) Botulinum neurotoxin type B and physical therapy in the treatment of piriformis syndrome. Am J Phys Med Rehabil 83:42–50PubMedCrossRefGoogle Scholar
  12. 12.
    Fishman LM, Zybert PA (1992) Electrophysiologic evidence of piriformis syndrome. Arch Phys Med Rehabil 73(4):359–364PubMedCrossRefGoogle Scholar
  13. 13.
    Freiberg AH (1937) Sciatic pain and its relief by operations on muscle and fascia. Arch Surg 34:337–350Google Scholar
  14. 14.
    Freiberg AH, Vinke TA (1934) Sciatica and the sacroiliac joint. J Bone Joint Surg [Am] 16:126–136Google Scholar
  15. 15.
    Georgiadis GM, Olexa TA, Ebraheim NA (1996) Entry sites for antegrade femoral nailing. Clin Orthop 330:281–287PubMedCrossRefGoogle Scholar
  16. 16.
    Hollinshead H (1964) Anatomy for surgeons, vol 3. Back and Limbs. Holber Medical Division, Harper & Row, New York, pp 690–691Google Scholar
  17. 17.
    Karl RD Jr, Yedinak MA, Hartshorne MF, Cawthon MA, Baumann JM, Howard WH, Bunker SR (1985) Scintigraphic appearance of the piriformis muscle syndrome. Clin Nucl Med 10(5):361–363PubMedCrossRefGoogle Scholar
  18. 18.
    Kim S, Choi JY, Huh YM, Song HT, Lee SA, Kim SM, Suh JS (2006) Role of magnetic resonance imaging in entrapment and compressive neuropathy-what, where, and how to see the peripheral nerves on the musculoskeletal magnetic resonance image: part 1. Overview and lower extremity. Eur Radiol 30 [Epub ahead of print]Google Scholar
  19. 19.
    Kirkaldy-Willis WH, Hill RJ (1979) A more precise diagnosis for low-back pain. Spine 4(2):102–109PubMedCrossRefGoogle Scholar
  20. 20.
    Meknas K, Christensen A, Johansen O (2003) The internal obturator muscle may cause sciatic pain. Pain 104:375–380PubMedCrossRefGoogle Scholar
  21. 21.
    Moore KL, Persaud TVN (1993) The developing human. Clinically oriented embryology. WB Saunders Company, Philadelphia, London, pp 376–382Google Scholar
  22. 22.
    Pace JB, Nagele D (1976) Piriform syndrome. West J Med 124:435–439PubMedGoogle Scholar
  23. 23.
    Papadakis SA, Shepherd L, Babourda EC, Papadakis S (2005) Piriform and trochanteric fossae. A drawing mismatch or a terminology error? A review. Surg Radiol Anat 27:223–226PubMedCrossRefGoogle Scholar
  24. 24.
    Papadopoulos EC, Khan SN (2004) Piriformis syndrome and low back pain: a new classification and review of the literature. Orthop Clin North Am 35(1):65–71PubMedCrossRefGoogle Scholar
  25. 25.
    Parziale JR, Hudgins TH, Fishman LM (1996) The Piriformis syndrome. Am J Orthop 25(12):819–823PubMedGoogle Scholar
  26. 26.
    Pokorný D, Jahoda D, Veigl D, Pinskerová V, Sosna A (2006) Topographic variations of the relationship of the sciatic nerve and the piriformis muscle and its relevance to palsy after total hip arthroplasty. Surg Radiol Anat 28:88–91PubMedCrossRefGoogle Scholar
  27. 27.
    Porta M (2000) A comparative trial of botulinum toxin type A and methylprednisolone for the treatment of myofascial pain syndrome and pain from chronic muscle spasm. Pain 85:101–105PubMedCrossRefGoogle Scholar
  28. 28.
    Rask MR (1980) Superior gluteal nerve entrapment syndrome. Muscle Nerve 3(4):304–307PubMedCrossRefGoogle Scholar
  29. 29.
    Robinson DR (1947) Piriformis syndrome in relation to sciatic pain. Am J Surg 73:355–358CrossRefPubMedGoogle Scholar
  30. 30.
    Sayson SC, Ducey JP, Maybrey JB, Wesley RL, Vermilion D (1994) Sciatic entrapment neuropathy associated with an anomalous piriformis muscle. Pain 59(1):149–152PubMedCrossRefGoogle Scholar
  31. 31.
    Silver JK, Leadbetter WB (1998) Piriformis syndrome: assessment of current practice and literature review. Orthopedics 21(10):1133–1135PubMedGoogle Scholar
  32. 32.
    Solheim LF, Siewers P, Paus B (1981) The piriformis muscle syndrome. Acta Orthop Scand 52(1):73–75PubMedCrossRefGoogle Scholar
  33. 33.
    Sosna A, Pokorny D, Jahoda D (2005) Sciatic nerve palsy after total hip replacement. J Bone Joint Surg [Br] 87-B:1140–1141Google Scholar
  34. 34.
    Souza TA (2005) Differential diagnosis and management for the chiropractor: protocols and algorithms, 3rd edn. Jone and Bartlett Pub., SudburyGoogle Scholar
  35. 35.
    Spratt JD, Stanley AJ, Grainger AJ, Hide IG, Campbell RS (2002) The role of diagnostic radiology in compressive and entrapment neuropathies. Eur Radiol 12:2352–2364PubMedGoogle Scholar
  36. 36.
    Steiner C, Staubs C, Ganon M, Buhlinger C (1987) Piriformis syndrome: pathogenesis, diagnosis, treatment. J Am Osteopath Assoc 87(4):318–323PubMedGoogle Scholar
  37. 37.
    Thiel W (1992) Die Konservierung ganzer Leichen in natürlichen Farben. [The preservation of the whole corps with natural color]. Ann Anat 174:185–195PubMedGoogle Scholar
  38. 38.
    Thiele GH (1937) Coccydynia and pain in the superior gluteal region. JAMA 109:1271–1275Google Scholar
  39. 39.
    Travell JG, Simons DG (2000) Handbuch der Muskel- Triggerpunkte. Untere Extremität. Urban & Fischer, München, Jena, pp 214–228Google Scholar
  40. 40.
    Williams PL (1999) Gray’s anatomy 38th Eng. Ed Churchill Livingstone, London, pp 876–877Google Scholar
  41. 41.
    Yeoman W (1928) The relation of arthritis of the sacroiliac joint to sciatica. Lancet 2:1119–1122CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Gunther Windisch
    • 1
  • Eva Maria Braun
    • 1
  • Friedrich Anderhuber
    • 1
  1. 1.Institute of AnatomyMedical University GrazGrazAustria

Personalised recommendations