Retro-odontoid Degenerative Pseudotumour Causing Spinal Cord Compression and Myelopathy: Current Evidence on the Role of Posterior C1–C2 Fixation in Treatment

  • Francesco Certo
  • Massimiliano Maione
  • Massimiliano Visocchi
  • Giuseppe M. V. Barbagallo
Part of the Acta Neurochirurgica Supplement book series (NEUROCHIRURGICA, volume 125)


Background: A retro-odontoid pseudotumour compressing the spinal cord and causing myelopathy is often associated with an inflammatory condition such as rheumatoid arthritis. A degenerative non-inflammatory retro-odontoid pseudotumour responsible for clinically relevant spinal cord compression is a rare condition described in small clinical series and is likely associated with craniovertebral junction hypermobility or instability–like conditions. For several years, direct removal of the lesion through an anterior or lateral approach has been advocated as the best surgical option. However, in the last decade the posterior approach to the craniovertebral junction, to perform C1–C2 fixation and C1 laminectomy without removal of the retro-odontoid tissue, has demonstrated its efficacy in reducing retro-odontoid pannus as well as in obtaining improvement of myelopathy.

Methods: In this paper we analyse the clinical and radiological outcomes of seven patients (five males and two females) treated with posterior C1–C2 fixation and C1 laminectomy for a degenerative non-inflammatory retro-odontoid pseudotumour responsible for spinal cord compression. C1 laminectomy provided immediate spinal cord decompression. We also review the relevant literature focusing on associated cervical degenerative conditions that may contribute to triggering or acceleration of atlantoaxial hypermobility or ‘instability’, causing formation of the retro-odontoid tissue.

Results: The mean follow-up period (of six followed-up patients) was 55.8 months (range 10–96 months). In all cases the Nurick score at the latest follow-up visit demonstrated clinical improvement; magnetic resonance imaging during follow-up demonstrated progressive reduction of the retro-odontoid pseudotumour in all but one patient, who died of surgery-unrelated disease in the early postoperative period. No vascular or neural damage secondary to C1–C2 fixation was observed.

Conclusion: C1–C2 fixation associated with C1 laminectomy is an effective surgical option to treat myelopathy secondary to a degenerative retro-odontoid pseudotumour. In these cases, direct removal of intracanalar tissue compressing the spinal cord is not required, as C1–C2 fixation is sufficient to cause its disappearance.


Atlantoaxial fixation Craniovertebral junction Cervical myelopathy Odontoid process Retro-odontoid pseudotumour 


Competing Interests

The authors declare that they have no competing interests.

Compliance with Ethical Standards

No financial support was received for this work.


  1. 1.
    Sze G, Brant-Zawadzki MN, Wilson CR, Norman D, Newton TH. Pseudotumor of the craniovertebral junction associated with chronic subluxation: MR imaging studies. Radiology. 1986;161:391–4.CrossRefGoogle Scholar
  2. 2.
    Suetsuna F, Narita H, Ono A, Ohishi H. Regression of retroodontoid pseudotumors following C1 laminoplasty. J Neurosurg Spine. 2006;5:455–60.CrossRefGoogle Scholar
  3. 3.
    Chang H, Park JB, Kim KW, Choi WS. Retro-dental reactive lesions related to development of myelopathy in patients with atlantoaxial instability secondary to os odontoideum. Spine (Phila Pa 1976). 2000;25:2777–83.CrossRefGoogle Scholar
  4. 4.
    Chikuda H, Seichi A, Takeshita K, Shoda N, Ono T, Matsudaira K, Kawaguchi H, Nakamura K. Radiographic analysis of the cervical spine in patients with retro-odontoid pseudotumors. Spine (Phila Pa 1976). 2009;34(3):E110–4.CrossRefGoogle Scholar
  5. 5.
    Crockard HA, Pozo JL, Ransford AO, Stevens JM, Kendall BE, Essigman WK. Transoral decompression and posterior fusion for rheumatoid atlanto-axial subluxation. J Bone Joint Surg Br. 1986;68:350–6.CrossRefGoogle Scholar
  6. 6.
    Lu K, Lee TC. Spontaneous regression of periodontoid pannus mass in psoriatic atlantoaxial subluxation. Case report. Spine (Phila Pa 1976). 1999;24:578–81.CrossRefGoogle Scholar
  7. 7.
    Young WF, Boyko O. Magnetic resonance imaging confirmation of resolution of periodontoid pannus formation following C1/C2 posterior transarticular screw fixation. J Clin Neurosci. 2002;9:434–6.CrossRefGoogle Scholar
  8. 8.
    Chang H, Park JB, Kim KW. Synovial cyst of the transverse ligament of the atlas in a patient with os odontoideum and atlantoaxial instability. Spine (Phila Pa 1976). 2000;25(6):741–4.CrossRefGoogle Scholar
  9. 9.
    Jun BY. Complete reduction of retro-odontoid soft tissue mass in os odontoideum following the posterior C1–C2 transarticular screw fixation. Spine (Phila Pa 1976). 1999;24:1961–4.CrossRefGoogle Scholar
  10. 10.
    Lagares A, Arrese I, Pascual B, Gomez PA, Ramos A, Lobato RD. Pannus resolution after occipitocervical fusion in a nonrheumatoid atlanto-axial instability. Eur Spine J. 2006;15:366–9.CrossRefGoogle Scholar
  11. 11.
    Matsumoto T, Takada S, Tsujimoto K, Ozaki T, Ishimoto K, Tsumura N, Shiba R, Kurosada M. Enlarging retro-odontoid pseudotumor after expanding cervical laminoplasty in the presence of kyphosis. Spine J. 2006;6(3):228–32.CrossRefGoogle Scholar
  12. 12.
    Rousselin B, Helenon O, Zingraff J, Delons S, Drueke T, Bardin T, Moreau JF. Pseudotumor of the craniocervical junction during long-term hemodialysis. Arthritis Rheum. 1990;33:1567–73.CrossRefGoogle Scholar
  13. 13.
    Isono M, Ishii K, Kamida T, Fujiki M, Goda M, Kobayashi H. Retroodontoid soft tissue mass associated with atlantoaxial subluxation in an elderly patient: a case report. Surg Neurol. 2001;55:223–7.CrossRefGoogle Scholar
  14. 14.
    Tojo S, Kawakami R, Yonenaga T, Hayashi D, Fukuda K. Factors influencing on retro-odontoid soft-tissue thickness: analysis by magnetic resonance imaging. Spine (Phila Pa 1976). 2013;38(5):401–6.CrossRefGoogle Scholar
  15. 15.
    Takami T, Goto T, Tsuyuguchi N, Nishikawa M, Ohata K. Posterior C1-2 fixation with cancellous screw and rod system for retro-odontoid pseudotumor associated with chronic atlantoaxial subluxation. Technical note. Neurol Med Chir (Tokyo). 2007;47(4):189–94.CrossRefGoogle Scholar
  16. 16.
    Barbagallo GMV, Certo F, Visocchi M, Palmucci S, Sciacca G, Albanese V. Disappearance of degenerative, non-inflammatory, retro-odontoid pseudotumor following posterior C1–C2 fixation: case series and review of the literature. Eur Spine J. 2013;22(Suppl 6):S879–88. Scholar
  17. 17.
    Moskovich R, Crockard H. Posttraumatic atlanto-axial subluxation and myelopathy. Efficacy of anterior decompression. Spine (Phila Pa 1976). 1990;15:442–7.CrossRefGoogle Scholar
  18. 18.
    Oohori Y, Seichi A, Kawaguchi H, Tajiri Y, Oda H, Nakamura K. Retroodontoid pseudotumor resected by a high cervical lateral approach in a rheumatoid arthritis patient: a case report. J Orthop Sci. 2004;9:90–3.CrossRefGoogle Scholar
  19. 19.
    Finn MA, Bishop FS, Dailey AT. Surgical treatment of occipitocervical instability. Neurosurgery. 2008;63(5):961–9.CrossRefGoogle Scholar
  20. 20.
    Lansen TA, Kasoff SS, Tenner MS. Occipitocervical fusion for reduction of traumatic periodontoid hypertrophic cicatrix. Case report. J Neurosurg. 1990;73(3):466–7.CrossRefGoogle Scholar
  21. 21.
    Oda I, Abumi K, Sell LC, Haggerty CJ, Cunningham BW, McAfee PC. Biomechanical evaluation of five different occipito-atlanto-axial fixation techniques. Spine (Phila Pa 1976). 1999;24:2377–82.CrossRefGoogle Scholar
  22. 22.
    Zygmunt S, Saveland H, Brattstrom H, Ljunggren B, Larsson EM, Wollheim F. Reduction of rheumatoid periodontoid pannus following posterior occipito-cervical fusion visualised by magnetic resonance imaging. Br J Neurosurg. 1988;2:315–20.CrossRefGoogle Scholar
  23. 23.
    Cihanek M, Fuentes S, Metellus P, Pech-Gourg G, Dufour H, Grisoli F. Disappearance of retro-odontoid pseudotumor after C1–C2 transarticular fixation screw. Neurochirurgie. 2008;54(1):32–6.CrossRefGoogle Scholar
  24. 24.
    Grob D, Wursch R, Grauer W, Sturzenegger J, Dvorak J. Atlantoaxial fusion and retrodental pannus in rheumatoid arthritis. Spine (Phila Pa 1976). 1997;22:1580–4.CrossRefGoogle Scholar
  25. 25.
    Ogata T, Kawatani Y, Morino T, Yamamoto H. Resolution of intraspinal retro-odontoid cyst associated with os odontoideum after posterior fixation. J Spinal Disord Tech. 2009;22(1):58–61.CrossRefGoogle Scholar
  26. 26.
    Tanaka S, Nakada M, Hayashi Y, Mohri M, Hayashi Y, Uchiyama N, Hamada J. Retro-odontid pseudotumor without atlantoaxial subluxation. Case report. J Clin Neurosci. 2009;17:649–52.CrossRefGoogle Scholar
  27. 27.
    Tessitore E, Bartoli A, Schaller K, Payer M. Accuracy of freehand fluoroscopy-guided placement of C1 lateral mass and C2 isthmic screws in atlanto-axial instability. Acta Neurochir. 2011;153:1417–25.CrossRefGoogle Scholar
  28. 28.
    Yamaguchi I, Shibuia S, Arima N, Oka S, Kanda Y, Yamamoto T. Remarkable reduction or disappearance of retroodontoid pseudotumors after occipitocervical fusion. J Neurosurg Spine. 2006;5:156–60.CrossRefGoogle Scholar
  29. 29.
    Yonezawa I, Okuda T, Won J, Sakoda J, Nakahara D, Nojiri H, Muto O, Momomura R, Kaneko K. Retrodental mass in rheumatoid arthritis. J Spinal Disord Tech. 2013;26(2):E65–9.CrossRefGoogle Scholar
  30. 30.
    Larsson EM, Holtas S, Zygmunt S. Pre- and postoperative MR imaging of the craniocervical junction in rheumatoid arthritis. Am J Roentgenol. 1989;152(3):561–6.CrossRefGoogle Scholar
  31. 31.
    Kakutani K, Doita M, Yoshikawa M, Okamoto K, Maeno K, Yurube T, Sha N, Kurosaka M, Nishida K. C1 laminectomy for retro-odontoid pseudotumor without atlantoaxial subluxation: review of seven consecutive cases. Eur Spine J. 2013;22(5):1119–26.CrossRefGoogle Scholar
  32. 32.
    Goel A, Laheri V. Plate and screw fixation for atlanto-axial subluxation. Acta Neurochir. 1994;129(1–2):47–53.CrossRefGoogle Scholar
  33. 33.
    Goel A. Treatment of basilar invagination by atlantoaxial joint distraction and direct lateral mass fixation. J Neurosurg Spine. 2004;1:281–6.CrossRefGoogle Scholar
  34. 34.
    Harms J, Melcher RP. Posterior C1–C2 fusion with polyaxial screw and rod fixation. Spine (Phila Pa 1976). 2001;26(22):2467–71.CrossRefGoogle Scholar
  35. 35.
    Jacobson ME, Khan SN, An HS. C1–C2 posterior fixation: indications, technique, and results. Orthop Clin North Am. 2012;43(1):11–8.CrossRefGoogle Scholar
  36. 36.
    Lee S-H, Kim SE, Sung J, Park Y, Eoh W. Clinical and radiological comparison of treatment of atlantoaxial instability by posterior C1–C2 transarticular screw fixation or C1 lateral mass–C2 pedicle screw fixation. J Clin Neurosci. 2010;17:886–92.CrossRefGoogle Scholar
  37. 37.
    Magerl F, Seeman PS. Stable posterior fusion of the atlas and axis by transarticular screw fixation. In: Kehr P, Weidner A, editors. Cervical spine. Vienna: Springer; 1987. p. 322–7.CrossRefGoogle Scholar
  38. 38.
    Thompson RC Jr, Meyer TJ. Posterior surgical stabilization for atlanto-axial subluxation in rheumatoid arthritis. Spine (Phila Pa 1976). 1985;10:597–601.CrossRefGoogle Scholar
  39. 39.
    Vergara P, Bal JS, Hickman Casey AT, Crockard HA, Choi D. C1–C2 posterior fixation: are four screws better than two? Neurosurgery. 2011;71(1 Suppl Operative):86–95.Google Scholar
  40. 40.
    Wright NM. Posterior C2 fixation using bilateral, crossing C2 laminar screws: case series and technical note. J Spinal Disord Tech. 2004;17(2):158–62.CrossRefGoogle Scholar
  41. 41.
    Nishizawa S, Ryu H, Yokoyama T, Uemura K. Myelopathy caused by retro-odontoid disc hernia: case report. Neurosurgery. 1996;39(6):1256–9.CrossRefGoogle Scholar
  42. 42.
    Shah A, Jain S, Kaswa A, Goel A. Immediate postoperative disappearance of retro-odontoid “pseudotumor”. World Neurosurg. 2016;91:419–23.CrossRefGoogle Scholar
  43. 43.
    Ito T, Hayashi M, Ogino T. Retrodental synovial cyst which disappeared after posterior C1–C2 fusion: a case report. J Orthop Surg (Hong Kong). 2000;8:83–7.CrossRefGoogle Scholar
  44. 44.
    Yamazaki M, Okawa A, Mannoji C, Katoda R, Miyashita T, Koda M. C1 dome-like laminotomy and posterior C1–C2 polyaxial screw–rod fixation for a patient with cervical myelopathy due to a retro-odontoid pseudotumor. J Clin Neurosci. 2009;16:99–103.CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2019

Authors and Affiliations

  • Francesco Certo
    • 1
  • Massimiliano Maione
    • 1
  • Massimiliano Visocchi
    • 2
  • Giuseppe M. V. Barbagallo
    • 1
  1. 1.Department of Neurological SurgeryPoliclinico “Gaspare Rodolico” University HospitalCataniaItaly
  2. 2.Institute of NeurosurgeryCatholic University of RomeRomeItaly

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