European Spine Journal

, Volume 18, Issue 10, pp 1478–1485 | Cite as

Non-fusion instrumentation of the lumbar spine with a hinged pedicle screw rod system: an in vitro experiment

  • Werner Schmoelz
  • U. Onder
  • A. Martin
  • A. von Strempel
Original Article

Abstract

In advanced stages of degenerative disease of the lumbar spine instrumented spondylodesis is still the golden standard treatment. However, in recent years dynamic stabilisation devices are being implanted to treat the segmental instability due to iatrogenic decompression or segmental degeneration. The purpose of the present study was to investigate the stabilising effect of a classical pedicle screw/rod combination, with a moveable hinge joint connection between the screw and rod allowing one degree of freedom (cosmicMIA). Six human lumbar spines (L2–5) were loaded in a spine tester with pure moments of ±7.5 Nm in lateral bending, flexion/extension and axial rotation. The range of motion (ROM) and the neutral zone were determined for the following states: (1) intact, (2) monosegmental dynamic instrumentation (L4-5), (3) bisegmental dynamic instrumentation (L3–5), (4) bisegmental decompression (L3–5), (5) bisegmental dynamic instrumentation (L3–5) and (6) bisegmental rigid instrumentation (L3–5). Compared to the intact, with monosegmental instrumentation (2) the ROM of the treated segment was reduced to 47, 40 and 77% in lateral bending, flexion/extension and axial rotation, respectively. Bisegmental dynamic instrumentation (3) further reduced the ROM in L4-5 compared to monosegmental instrumentation to 25% (lateral bending), 28% (flexion/extension) and 57% (axial rotation). Bisegmental surgical decompression (4) caused an increase in ROM in both segments (L3–4 and L4–5) to approximately 125% and approximately 135% and 187–234% in lateral bending, flexion/extension and axial rotation, respectively. Compared to the intact state, bisegmental dynamic instrumentation after surgical decompression reduced the ROM of the two-bridged segments to 29–35% in lateral bending and 33–38% in flexion/extension. In axial rotation, the ROM was in the range of the intact specimen (87–117%). A rigid instrumentation (6) further reduced the ROM of the two-bridged segments to 20–30, 23–27 and 50–68% in lateral bending, flexion/extension and axial rotation, respectively. The results of the present study showed that compared to the intact specimen the investigated hinged dynamic stabilisation device reduced the ROM after bisegmental decompression in lateral bending and flexion/extension. Following bisegmental decompression and the thereby caused large rotational instability the device is capable of restoring the motion in axial rotation back to values in the range of the intact motion segments.

Keywords

Dynamic stabilisation Biomechanics Lumbar spine Decompression 

Notes

Acknowledgment

The work was supported by corporate funds (Ulrich Medical, Ulm, Germany).

References

  1. 1.
    Adams MA, Hutton WC (1981) The relevance of torsion to the mechanical derangement of the lumbar spine. Spine 6:241–248. doi: 10.1097/00007632-198105000-00006 PubMedCrossRefGoogle Scholar
  2. 2.
    Bothmann M, Kast E, Boldt GJ, Oberle J (2008) Dynesys fixation for lumbar spine degeneration. Neurosurg Rev 31:189–196. doi: 10.1007/s10143-007-0101-9 PubMedCrossRefGoogle Scholar
  3. 3.
    Cheng BC, Gordon J, Cheng J, Welch WC (2007) Immediate biomechanical effects of lumbar posterior dynamic stabilization above a circumferential fusion. Spine 32:2551–2557. doi: 10.1097/BRS.0b013e318158cdbe PubMedCrossRefGoogle Scholar
  4. 4.
    Cripton PA, Jain GM, Wittenberg RH, Nolte LP (2000) Load-sharing characteristics of stabilized lumbar spine segments. Spine 25:170–179. doi: 10.1097/00007632-200001150-00006 PubMedCrossRefGoogle Scholar
  5. 5.
    Disch AC, Schaser KD, Melcher I, Luzzati A, Feraboli F, Schmoelz W (2008) En bloc spondylectomy reconstructions in a biomechanical in-vitro study. Eur Spine J 17:715–725. doi: 10.1007/s00586-008-0588-y PubMedCrossRefGoogle Scholar
  6. 6.
    Disch AC, Schmoelz W, Matziolis G, Schneider SV, Knop C, Putzier M (2008) Higher risk of adjacent segment degeneration after floating fusions: long-term outcome after low lumbar spine fusions. J Spinal Disord Tech 21:79–85. doi: 10.1097/BSD.0b013e3180577259 PubMedCrossRefGoogle Scholar
  7. 7.
    Fuchs PD, Lindsey DP, Hsu KY, Zucherman JF, Yerby SA (2005) The use of an interspinous implant in conjunction with a graded facetectomy procedure. Spine 30:1266–1272. doi: 10.1097/01.brs.0000164152.32734.d2 discussion 1273–1274PubMedCrossRefGoogle Scholar
  8. 8.
    Fujiwara A, Lim TH, An HS, Tanaka N, Jeon CH, Andersson GB, Haughton VM (2000) The effect of disc degeneration and facet joint osteoarthritis on the segmental flexibility of the lumbar spine. Spine 25:3036–3044. doi: 10.1097/00007632-200012010-00011 PubMedCrossRefGoogle Scholar
  9. 9.
    Ghiselli G, Wang JC, Bhatia NN, Hsu WK, Dawson EG (2004) Adjacent segment degeneration in the lumbar spine. J Bone Joint Surg Am 86A:1497–1503Google Scholar
  10. 10.
    Goel VK, Panjabi MM, Patwardhan AG, Dooris AP, Serhan H (2006) Test protocols for evaluation of spinal implants. J Bone Joint Surg Am 88(Suppl 2):103–109. doi: 10.2106/JBJS.E.01363 PubMedCrossRefGoogle Scholar
  11. 11.
    Grob D, Benini A, Junge A, Mannion AF (2005) Clinical experience with the Dynesys semirigid fixation system for the lumbar spine: surgical and patient-oriented outcome in 50 cases after an average of 2 years. Spine 30:324–331. doi: 10.1097/01.brs.0000152584.46266.25 PubMedCrossRefGoogle Scholar
  12. 12.
    Hilibrand AS, Robbins M (2004) Adjacent segment degeneration and adjacent segment disease: the consequences of spinal fusion? Spine J 4:190S–194S. doi: 10.1016/j.spinee.2004.07.007 PubMedCrossRefGoogle Scholar
  13. 13.
    Kettler A, Drumm J, Heuer F, Haeussler K, Mack C, Claes L, Wilke HJ (2008) Can a modified interspinous spacer prevent instability in axial rotation and lateral bending? A biomechanical in vitro study resulting in a new idea. Clin Biomech (Bristol, Avon) 23:242–247. doi: 10.1016/j.clinbiomech.2007.09.004 CrossRefGoogle Scholar
  14. 14.
    Khoueir P, Kim KA, Wang MY (2007) Classification of posterior dynamic stabilization devices. Neurosurg Focus 22:E3. doi: 10.3171/foc.2007.22.1.3 PubMedCrossRefGoogle Scholar
  15. 15.
    Kim SM, Lim TJ, Paterno J, Kim DH (2004) A biomechanical comparison of supplementary posterior translaminar facet and transfacetopedicular screw fixation after anterior lumbar interbody fusion. J Neurosurg Spine 1:101–107PubMedCrossRefGoogle Scholar
  16. 16.
    Knop C, Lange U, Bastian L, Blauth M (2000) Three-dimensional motion analysis with Synex. Comparative biomechanical test series with a new vertebral body replacement for the thoracolumbar spine. Eur Spine J 9:472–485. doi: 10.1007/s005860000185 PubMedCrossRefGoogle Scholar
  17. 17.
    Meyers K, Tauber M, Sudin Y, Fleischer S, Arnin U, Girardi F, Wright T (2008) Use of instrumented pedicle screws to evaluate load sharing in posterior dynamic stabilization systems. Spine J 8:926–932. doi: 10.1016/j.spinee.2007.08.008 PubMedCrossRefGoogle Scholar
  18. 18.
    Niosi CA, Zhu QA, Wilson DC, Keynan O, Wilson DR, Oxland TR (2006) Biomechanical characterization of the three-dimensional kinematic behaviour of the Dynesys dynamic stabilization system: an in vitro study. Eur Spine J 15:913–922. doi: 10.1007/s00586-005-0948-9 PubMedCrossRefGoogle Scholar
  19. 19.
    Panjabi MM (1988) Biomechanical evaluation of spinal fixation devices: I. A conceptual framework. Spine 13:1129–1134PubMedCrossRefGoogle Scholar
  20. 20.
    Panjabi MM, Henderson G, James Y, Timm JP (2007) StabilimaxNZ® versus simulated fusion: evaluation of adjacent-level effects. Eur Spine J 16:2159–2165. doi: 10.1007/s00586-007-0444-5 PubMedCrossRefGoogle Scholar
  21. 21.
    Panjabi MM, Krag M, Summers D, Videman T (1985) Biomechanical time-tolerance of fresh cadaveric human spine specimens. J Orthop Res 3:292–300. doi: 10.1002/jor.1100030305 PubMedCrossRefGoogle Scholar
  22. 22.
    Panjabi MM, Oxland TR, Yamamoto I, Crisco JJ (1994) Mechanical behavior of the human lumbar and lumbosacral spine as shown by three-dimensional load-displacement curves. J Bone Joint Surg Am 76:413–424PubMedGoogle Scholar
  23. 23.
    Phillips FM, Voronov LI, Gaitanis IN, Carandang G, Havey RM, Patwardhan AG (2006) Biomechanics of posterior dynamic stabilizing device (DIAM) after facetectomy and discectomy. Spine J 6:714–722. doi: 10.1016/j.spinee.2006.02.003 PubMedCrossRefGoogle Scholar
  24. 24.
    Quint U, Wilke HJ, Loer F, Claes L (1998) Laminectomy and functional impairment of the lumbar spine: the importance of muscle forces in flexible and rigid instrumented stabilization—a biomechanical study in vitro. Eur Spine J 7:229–238. doi: 10.1007/s005860050062 PubMedCrossRefGoogle Scholar
  25. 25.
    Schmoelz W, Huber JF, Nydegger T, Claes L, Wilke HJ (2003) Dynamic stabilization of the lumbar spine and its effects on adjacent segments: an in vitro experiment. J Spinal Disord Tech 16:418–423PubMedGoogle Scholar
  26. 26.
    Schulte TL, Hurschler C, Haversath M, Liljenqvist U, Bullmann V, Filler TJ, Osada N, Fallenberg EM, Hackenberg L (2008) The effect of dynamic, semi-rigid implants on the range of motion of lumbar motion segments after decompression. Eur Spine J 17:1057–1065. doi: 10.1007/s00586-008-0667-0 PubMedCrossRefGoogle Scholar
  27. 27.
    Scifert JL, Sairyo K, Goel VK, Grobler LJ, Grosland NM, Spratt KF, Chesmel KD (1999) Stability analysis of an enhanced load sharing posterior fixation device and its equivalent conventional device in a calf spine model. Spine 24:2206–2213. doi: 10.1097/00007632-199911010-00006 PubMedCrossRefGoogle Scholar
  28. 28.
    Stoll TM, Dubois G, Schwarzenbach O (2002) The dynamic neutralization system for the spine: a multi-center study of a novel non-fusion system. Eur Spine J 11(Suppl 2):S170–S178PubMedGoogle Scholar
  29. 29.
    Wilke HJ, Drumm J, Haussler K, Mack C, Steudel WI, Kettler A (2008) Biomechanical effect of different lumbar interspinous implants on flexibility and intradiscal pressure. Eur Spine J 17:1049–1056PubMedCrossRefGoogle Scholar
  30. 30.
    Wilke HJ, Heuer F, Schmidt H (2008) Design optimization of a new posterior dynamic stabilization system. J Biomech 41(Suppl 1):S313. doi: 10.1016/S0021-9290(08)70312-9 CrossRefGoogle Scholar
  31. 31.
    Wilke HJ, Jungkunz B, Wenger K, Claes LE (1998) Spinal segment range of motion as a function of in vitro test conditions: effects of exposure period, accumulated cycles, angular-deformation rate, and moisture condition. Anat Rec 251:15–19. doi: 10.1002/(SICI)1097-0185(199805)251:1<15::AID-AR4>3.0.CO;2-D PubMedCrossRefGoogle Scholar
  32. 32.
    Wilke HJ, Schmidt H, Werner K, Schmolz W, Drumm J (2006) Biomechanical evaluation of a new total posterior-element replacement system. Spine 31:2790–2796. doi: 10.1097/01.brs.0000245872.45554.c0 discussion 2797PubMedCrossRefGoogle Scholar
  33. 33.
    Wilke HJ, Wenger K, Claes L (1998) Testing criteria for spinal implants: recommendations for the standardization of in vitro stability testing of spinal implants. Eur Spine J 7:148–154. doi: 10.1007/s005860050045 PubMedCrossRefGoogle Scholar
  34. 34.
    Zander T, Rohlmann A, Klockner C, Bergmann G (2003) Influence of graded facetectomy and laminectomy on spinal biomechanics. Eur Spine J 12:427–434. doi: 10.1007/s00586-003-0540-0 PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Werner Schmoelz
    • 1
  • U. Onder
    • 1
  • A. Martin
    • 2
  • A. von Strempel
    • 2
  1. 1.Department of Trauma SurgeryMedical University InnsbruckInnsbruckAustria
  2. 2.Department of Orthopedic SurgeryLandeskrankenhaus FeldkirchFeldkirchAustria

Personalised recommendations