European Spine Journal

, 20:1281 | Cite as

Polymethylmethacrylate augmentation of the pedicle screw: the cement distribution in the vertebral body

  • Ming-Hsien Hu
  • Hung Ta H. Wu
  • Ming-Chau Chang
  • Wing-Kuang Yu
  • Shih-Tien Wang
  • Chien-Lin Liu
Original Article

Abstract

Many studies have proven that the polymethylmethacrylate (PMMA) augmentation of the pedicle screw can significantly increase stiffness and strength of spinal fixation. Some major complications have also been reported. However, there are no reports discussing cement distribution and its morphology in the osteoporotic vertebral body, which is critical in the analysis of the biomechanical strength of the pedicle screw and the risk of cement leakage after pedicle screw augmentation. In this study, we used computed tomography (CT) to evaluate the cement distribution in the osteoporotic vertebral body after PMMA augmentation of a pedicle screw and to analyze the factors leading to cement leakage. Two groups of patients were studied. Group A consisted 25 osteoporotic patients (mean age of 73 years) with spinal instrumentation who had a total of 145 pedicle screws and cement augmentation with biopsy needles. Group B consisted of 23 osteoporotic patients (mean age of 74.6 years) with spinal instrumentation who had a total of 125 cannulated pedicle screws with cement augmentation. All patients had CT evaluation of the cement distribution in the vertebral body after the surgery. The cement distribution in the vertebrae was divided into four zones in the axial CT view: anterior one-third, middle third, and posterior third of vertebral body, and the pedicle. The morphology of the cement distribution around the pedicle screw was defined as scattered type or concentrate type. The leakage pattern was divided to anterior–lateral, posterior–lateral, and canal leakage. The correlations among bone mineral density (BMD), the cement leakage rate, and cement distribution morphology were also analyzed. The results showed that most augmented pedicle screws had cement extension into three of the four zones of the vertebral body (66.3%), followed by two zones (20%), all four zones (11.5%), and only one zone (2.2%). Overall, 123 screws (84.8%) in Group A and 108 screws (86.4%) in Group B had cement concentrate type distribution. The cement leakage rate in Group A is 18.3% and 13.6% in Group B. Patients with a BMD <0.6 g/cm2 had significantly higher rates of cement leakage and tended toward a scattered cement distribution. There was only one patient who had a symptomatic leakage (sciatica) in Group B. We concluded that the cement distribution after pedicle screw augmentation with biopsy needle or cannulated screw technique was mostly localized in three zones of the vertebral body, and patients with lower BMD had a higher risk of cement leakage and scattered cement distribution.

Keywords

Cannulated pedicle screw Cement augmentation Osteoporosis Polymethylmethacrylate 

Notes

Conflict of interest

None.

References

  1. 1.
    Becker S, Chavanne A, Spitaler R et al (2008) Assessment of different screw augmentation techniques and screw designs in osteoporotic spines. Eur Spine J 17:1462–1469PubMedCrossRefGoogle Scholar
  2. 2.
    Burval DJ, McLain RF, Milks R et al (2007) Primary pedicle screw augmentation in osteoporotic lumbar vertebrae: biomechanical analysis of pedicle fixation strength. Spine 32:1077–1083PubMedCrossRefGoogle Scholar
  3. 3.
    Chang MC, Liu CL, Chen TH et al (2008) Polymethylmethacrylate augmentation of pedicle screw for osteoporotic spinal surgery: a novel technique. Spine 33:E317–E324PubMedCrossRefGoogle Scholar
  4. 4.
    Chen LH, Tai CL, Lai PL et al (2009) Pullout strength for cannulated pedicle screws with bone cement augmentation in severely osteoporotic bone: influences of radial hole and pilot hole tapping. Clin Biomech (Bristol, Avon) 24:613–618CrossRefGoogle Scholar
  5. 5.
    Coe JD, Warden KE, Engr M et al (1990) Influence of bone mineral density on the fixation of thoracolumbar implants: a comparative study of transpedicular screws, laminar hooks, and spinous process wires. Spine 15:902–907PubMedCrossRefGoogle Scholar
  6. 6.
    Cook SD, Salkeld SL, Stanley T et al (2004) Biomechanical study of pedicle screw fixation in severely osteoporotic bone. Spine 4:402–408CrossRefGoogle Scholar
  7. 7.
    Halvorson TL, Kelly LA, Thomas KA et al (1994) Effects of bone mineral density on pedicle screw fixation. Spine 19:2415–2420PubMedCrossRefGoogle Scholar
  8. 8.
    Hirano T, Hasegawa K, Takahashi HE et al (1997) Structural characteristics of the pedicle and its role in screw stability. Spine 22:2504–2509PubMedCrossRefGoogle Scholar
  9. 9.
    Inceoglu S, Burghardt A, Akbay A et al (2005) Trabecular architecture of lumbar vertebral pedicle. Spine 30:1485–1490PubMedCrossRefGoogle Scholar
  10. 10.
    Kim YJ, Bridwell KH, Lenke LG et al (2006) Pseudarthrosis in long adult spinal deformity instrumentation and fusion to the sacrum: prevalence and risk factor analysis of 144 cases. Spine 31:2329–2336PubMedCrossRefGoogle Scholar
  11. 11.
    Kumano K, Hirabayashi S, Ogawa Y et al (1994) Pedicle screws and bone mineral density. Spine 19:1157–1161PubMedCrossRefGoogle Scholar
  12. 12.
    Lebwohl NH, Cunningham BW, Dmitriev A et al (2002) Biomechanical comparison of lumbosacral fixation techniques in a calf spine model. Spine 27:2312–2320PubMedCrossRefGoogle Scholar
  13. 13.
    Lotz JC, Hu SS, Chieu DF et al (1997) Carbonated apatite cement augmentation of pedicle screw fixation in the lumbar spine. Spine 22:2716–2723PubMedCrossRefGoogle Scholar
  14. 14.
    McLain RF, McKinley TO, Yerby SA et al (1997) The effect of bone quality on pedicle screw loading in axial instability: a synthetic model. Spine 22:1454–1460PubMedCrossRefGoogle Scholar
  15. 15.
    Moon BJ, Cho BY, Choi EY et al (2009) Polymethylmethacrylate-augmented screw fixation for stabilization of the osteoporotic spine: a three-year follow-up of 37 patients. J Korean Neurosurg Soc 46:305–311PubMedCrossRefGoogle Scholar
  16. 16.
    Moore DC, Maitra RS, Farjo LA et al (1997) Restoration of pedicle screw fixation with an in situ setting calcium phosphate cement. Spine 22:1696–1705PubMedCrossRefGoogle Scholar
  17. 17.
    Okuyama K, Sato K, Abe E et al (1993) Stability of transpedicle screwing for the osteoporotic spine: an in vitro study of mechanical stability. Spine 18:2240–2245PubMedCrossRefGoogle Scholar
  18. 18.
    Pfeifer BA, Krag MH, Johnson C (1994) Repair of failed transpedicle screw fixation: a biomechanical study comparing polymethylmethacrylate, milled bone, and matchstick bone reconstruction. Spine 19:350–353PubMedCrossRefGoogle Scholar
  19. 19.
    Renner SM, Lim TH, Kim WJ et al (2004) Augmentation of pedicle screw fixation strength using an injectable calcium phosphate cement as a function of injection timing and method. Spine 29:E212–E216PubMedCrossRefGoogle Scholar
  20. 20.
    Soshi S, Shiba R, Kondo H et al (1991) An experimental study on transpedicular screw fixation in relation to osteoporosis of the lumbar spine. Spine 16:1335–1341PubMedCrossRefGoogle Scholar
  21. 21.
    Waits C, Burton D, McIff T (2009) Cement augmentation of pedicle screw fixation using novel cannulated cement insertion device. Spine 34:E478–E483PubMedCrossRefGoogle Scholar
  22. 22.
    Wittenberg RH, Shea M, Swartz DE et al (1991) Importance of bone mineral density in instrumented spine fusion. Spine 16:647–652PubMedCrossRefGoogle Scholar
  23. 23.
    Yamagata M, Kitahara H, Minami S et al (1992) Mechanical stability of the pedicle screw fixation systems for the lumbar spine. Spine 17(suppl 3):S51–S54PubMedCrossRefGoogle Scholar
  24. 24.
    Yerby SA, Toh E, McLain RF (1998) Revision of failed pedicle screws using hydroxyapatite cement: a biomechanical analysis. Spine 23:1657–1661PubMedCrossRefGoogle Scholar
  25. 25.
    Zhuang XM, Yu BS, Zheng ZM, et al (2010) Effect of the degree of osteoporosis on the biomechanical anchoring strength of the sacral pedicle screws: an in vitro comparison between unaugmented bicortical screws and polymethylmethacrylate augmented unicortical screws. Spine [Epub ahead of print]Google Scholar
  26. 26.
    Zindrick MR, Wiltse LL, Widell EH et al (1986) A biomechanical study of intrapeduncular screw fixation in the lumbosacral spine. Clin Orthop Relat Res 203:99–112PubMedGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Ming-Hsien Hu
    • 4
  • Hung Ta H. Wu
    • 2
  • Ming-Chau Chang
    • 1
    • 3
  • Wing-Kuang Yu
    • 1
  • Shih-Tien Wang
    • 1
  • Chien-Lin Liu
    • 1
  1. 1.Department of Orthopaedics and TraumatologyTaipei Veterans General HospitalTaipeiTaiwan, ROC
  2. 2.Department of RadiologyTaipei Veterans General HospitalTaipeiTaiwan, ROC
  3. 3.Institute of Anatomy and Cell Biology, School of MedicineNational Yang-Ming UniversityTaipeiTaiwan, ROC
  4. 4.Orthopedic DepartmentShow Chwan Memorial HospitalChanghuaTaiwan, ROC

Personalised recommendations