Technical Report| Volume 9, ISSUE 9, P744-753, September 2009

Download started.


Biomechanical characterization of an annulus-sparing spinal disc prosthesis


      Background context

      Current spine arthroplasty devices require disruption of the annulus fibrosus for implantation. Preliminary studies of a unique annulus-sparing intervertebral prosthetic disc (IPD) found that preservation of the annulus resulted in load sharing of the annulus with the prosthesis.


      Determine flexibility of the IPD versus fusion constructs in normal and degenerated human spines.

      Study design/setting

      Biomechanical comparison of motion segments in the intact, fusion and mechanical nucleus replacement states for normal and degenerated states.

      Patient setting

      Thirty lumbar motion segments.

      Outcomes measures

      Intervertebral height; motion segment range of motion, neutral zone, stiffness.


      Motion segments had multidirectional flexibility testing to 7.5 Nm for intact discs, discs reconstructed using the IPD (n=12), or after anterior/posterior fusions (n=18). Interbody height and axial compression stiffness changes were determined for the reconstructed discs by applying axial compression to 1,500 N. Analysis included stratifying results to normal mobile versus rigid degenerated intact motion segments.


      The mean interbody height increase was 1.5 mm for IPD reconstructed discs versus 3.0 mm for fused segments. Axial compression stiffness was 3.0±0.9 kN/mm for intact compared with 1.2±0.4 kN/mm for IPD reconstructed segments. Reconstructed disc ROM was 9.0°±3.7° in flexion extension, 10.6°±3.4° in lateral bending, and 2.8°±1.4° in axial torsion that was similar to intact values and significantly greater than respective fusion values (p<.001). Mobile intact segments exhibited significantly greater rotation after fusion versus their more rigid counterparts (p<.05); however, intact motion was not related to motion after IPD reconstruction. The NZ and rotational stiffness followed similar trends. Differences in NZ between mobile and rigid intact specimens tended to decrease in the IPD reconstructed state.


      The annulus-sparing IPD generally reproduced the intact segment biomechanics in terms of ROM, NZ, and stiffness. Furthermore, the IPD reconstructed discs imparted stability by maintaining a small neutral zone. The IPD reconstructed discs were significantly less rigid than the fusion constructs and may be an attractive alternative for the treatment of degenerative disc disease.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to The Spine Journal
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Gillet P.
        The fate of the adjacent motion segments after lumbar fusion.
        J Spinal Disord Tech. 2003; 16: 338-345
        • Ghiselli G.
        • Wang J.C.
        • Bhatia N.N.
        • et al.
        Adjacent segment degeneration in the lumbar spine.
        J Bone Joint Surg Am. 2004; 86-A: 1497-1503
        • Cheh G.
        • Bridwell K.H.
        • Lenke L.G.
        • et al.
        Adjacent segment disease following lumbar/thoracolumbar fusion with pedicle screw instrumentation: a minimum 5-year follow-up.
        Spine. 2007; 32: 2253-2257
        • Allen M.J.
        • Schoonmaker J.E.
        • Bauer T.W.
        • et al.
        Preclinical evaluation of a poly (vinyl alcohol) hydrogel implant as a replacement for the nucleus pulposus.
        Spine. 2004; 29: 515-523
        • Bao Q.B.
        • Yuan H.A.
        New technologies in spine: nucleus replacement.
        Spine. 2002; 27: 1245-1247
        • Eysel P.
        • Rompe J.
        • Schoenmayr R.
        • et al.
        Biomechanical behaviour of a prosthetic lumbar nucleus.
        Acta Neurochir (Wien). 1999; 141: 1083-1087
        • Husson J.L.
        • Korge A.
        • Polard J.L.
        • et al.
        A memory coiling spiral as nucleus pulposus prosthesis: concept, specifications, bench testing, and first clinical results.
        J Spinal Disord Tech. 2003; 16: 405-411
        • Di Martino A.
        • Vaccaro A.R.
        • Lee J.Y.
        • et al.
        Nucleus pulposus replacement: basic science and indications for clinical use.
        Spine. 2005; 30: S16-S22
        • Bertagnoli R.
        • Kumar S.
        Indications for full prosthetic disc arthroplasty: a correlation of clinical outcome against a variety of indications.
        Eur Spine J. 2002; 11: S131-S136
        • Cinotti G.
        • David T.
        • Postacchini F.
        Results of disc prosthesis after a minimum follow-up period of 2 years.
        Spine. 1996; 21: 995-1000
        • Buttermann G.R.
        • Beaubien B.P.
        Spinal load sharing of a compressible annulus sparing disc prosthesis.
        Spine J. 2004; 4: S4-S5
        • Buttermann G.R.
        • Beaubien B.P.
        Stiffness of prosthetic nucleus determines stiffness of reconstructed lumbar calf disc.
        Spine J. 2004; 4: 265-274
        • Ghiselli G.
        • Wang J.C.
        • Hsu W.K.
        • et al.
        L5-S1 segment survivorship and clinical outcome analysis after L4-L5 isolated fusion.
        Spine. 2003; 28: 1275-1280
        • Kramer P.A.
        Prevalence and distribution of spinal osteoarthritis in women.
        Spine. 2006; 31: 2843-2848
        • Kettler A.
        • Wilke H.J.
        Review of existing grading systems for cervical or lumbar disc and facet joint degeneration.
        Eur Spine J. 2006; 15: 705-718
        • Wilke H.J.
        • Rohlmann F.
        • Neidlinger-Wilke C.
        • et al.
        Validity and interobserver agreement of a new radiographic grading system for intervertebral disc degeneration: Part I. Lumbar spine.
        Eur Spine J. 2006; 15: 720-730
        • Beaubien B.P.
        • Derincek A.
        • Lew W.D.
        • et al.
        In vitro, biomechanical comparison of an anterior lumbar interbody fusion with an anteriorly placed, low-profile lumbar plate and posteriorly placed pedicle screws or translaminar screws.
        Spine. 2005; 30: 1846-1851
        • Cripton P.A.
        • Bruehlmann S.B.
        • Orr T.E.
        • et al.
        In vitro axial preload application during spine flexibility testing: towards reduced apparatus-related artefacts.
        J Biomech. 2000; 33: 1559-1568
      1. Buttermann GR. Annulus sparing lumbar disc prosthesis stability and motion preservation in an in vivo animal model. 6th Annual Meeting of the Spine Arthroplasty Society; 2006; Montreal, Canada.

        • Proctor C.S.
        • Schmidt M.B.
        • Whipple R.R.
        • et al.
        Material properties of the normal medial bovine meniscus.
        J Orthop Res. 1989; 7: 771-782
        • Thompson J.P.
        • Pearce R.H.
        • Schechter M.T.
        • et al.
        Preliminary evaluation of a scheme for grading the gross morphology of the human intervertebral disc.
        Spine. 1990; 15: 411-415
        • Nachemson A.L.
        • Elfstrom G.
        Intravital dynamic pressure measurements in lumbar discs. A study of common movements, maneuvers and exercises.
        Scand J Rehabil Med Suppl. 1970; 1: 1-40
        • Schultz A.
        • Andersson G.
        • Ortengren R.
        • et al.
        Loads on the lumbar spine. Validation of a biomechanical analysis by measurements of intradiscal pressures and myoelectric signals.
        J Bone Joint Surg Am. 1982; 64: 713-720
        • Nachemson A.
        Lumbar intradiscal pressure. Experimental studies on post-mortem material.
        Acta Orthop Scand Suppl. 1960; 43: 1-104
        • Koeller W.
        • Muehlhaus S.
        • Meier W.
        • et al.
        Biomechanical properties of human intervertebral discs subjected to axial dynamic compression—influence of age and degeneration.
        J Biomech. 1986; 19: 807-816
        • Shao Z.
        • Rompe G.
        • Schiltenwolf M.
        Radiographic changes in the lumbar intervertebral discs and lumbar vertebrae with age.
        Spine. 2002; 27: 263-268
        • Tibrewal S.B.
        • Pearcy M.J.
        Lumbar intervertebral disc heights in normal subjects and patients with disc herniation.
        Spine. 1985; 10: 452-454
        • Walsh A.J.
        • Lotz J.C.
        Biological response of the intervertebral disc to dynamic loading.
        J Biomech. 2004; 37: 329-337
        • Court C.
        • Chin J.R.
        • Liebenberg E.
        • et al.
        Biological and mechanical consequences of transient intervertebral disc bending.
        Eur Spine J. 2007;
        • Kroeber M.
        • Unglaub F.
        • Guegring T.
        • et al.
        Effects of controlled dynamic disc distraction on degenerated intervertebral discs: an in vivo study on the rabbit lumbar spine model.
        Spine. 2005; 30: 181-187
        • Guehring T.
        • Omlor G.W.
        • Lorenz H.
        • et al.
        Disc distraction shows evidence of regenerative potential in degenerated intervertebral discs as evaluated by protein expression, magnetic resonance imaging, and messenger ribonucleic acid expression analysis.
        Spine. 2006; 31: 1658-1665
        • Hirsch C.
        The reaction of intervertebral discs to compression forces.
        J Bone Joint Surg Am. 1955; 37-A: 1188-1196
        • Koeller W.
        • Meier W.
        • Hartmann F.
        Biomechanical properties of human intervertebral discs subjected to axial dynamic compression. A comparison of lumbar and thoracic discs.
        Spine. 1984; 9: 725-733
        • Lin H.S.
        • Liu Y.K.
        • Adams K.H.
        Mechanical response of the lumbar intervertebral joint under physiological (complex) loading.
        J Bone Joint Surg Am. 1978; 60: 41-55
        • Markolf K.L.
        • Morris J.M.
        The structural components of the intervertebral disc. A study of their contributions to the ability of the disc to withstand compressive forces.
        J Bone Joint Surg Am. 1974; 56: 675-687
        • Smeathers J.E.
        • Joanes D.N.
        Dynamic compressive properties of human lumbar intervertebral joints: a comparison between fresh and thawed specimens.
        J Biomech. 1988; 21: 425-433
        • Brown T.
        • Hansen R.J.
        • Yorra A.J.
        Some mechanical tests on the lumbosacral spine with particular reference to the intervertebral discs; a preliminary report.
        J Bone Joint Surg Am. 1957; 39-A: 1135-1164
        • Hirsch C.
        • Nachemson A.
        New observations on the mechanical behavior of lumbar discs.
        Acta Orthop Scand. 1954; 23: 254-283
        • Langrana N.A.
        • Parsons J.R.
        • Lee C.K.
        • et al.
        Materials and design concepts for an intervertebral disc spacer. I. Fiber-reinforced composite design.
        J Appl Biomater. 1994; 5: 125-132
        • Markolf K.L.
        Deformation of the thoracolumbar intervertebral joints in response to external loads: a biomechanical study using autopsy material.
        J Bone Joint Surg Am. 1972; 54: 511-533
        • Shea M.
        • Takeuchi T.Y.
        • Wittenberg R.H.
        • et al.
        A comparison of the effects of automated percutaneous diskectomy and conventional diskectomy on intradiscal pressure, disk geometry, and stiffness.
        J Spinal Disord. 1994; 7: 317-325
        • Joshi A.
        • Mehta S.
        • Vresilovic E.
        • et al.
        Nucleus implant parameters significantly change the compressive stiffness of the human lumbar intervertebral disc.
        J Biomech Eng. 2005; 127: 536-540
        • Andersson G.B.
        • Schultz A.B.
        Effects of fluid injection on mechanical properties of intervertebral discs.
        J Biomech. 1979; 12: 453-458
        • Lindsey D.P.
        • Swanson K.E.
        • Fuchs P.
        • et al.
        The effects of an interspinous implant on the kinematics of the instrumented and adjacent levels in the lumbar spine.
        Spine. 2003; 28: 2192-2197
        • Nachemson A.L.
        • Schultz A.B.
        • Berkson M.H.
        Mechanical properties of human lumbar spine motion segments. Influence of age, sex, disc level, and degeneration.
        Spine. 1979; 4: 1-8
        • Panjabi M.M.
        • Oxland T.R.
        • Yamamoto I.
        • et al.
        Mechanical behavior of the human lumbar and lumbosacral spine as shown by three-dimensional load-displacement curves.
        J Bone Joint Surg Am. 1994; 76: 413-424
        • Pearcy M.J.
        • Tibrewal S.B.
        Axial rotation and lateral bending in the normal lumbar spine measured by three-dimensional radiography.
        Spine. 1984; 9: 582-587
        • Schendel M.J.
        • Wood K.B.
        • Buttermann G.R.
        • et al.
        Experimental measurement of ligament force, facet force, and segment motion in the human lumbar spine.
        J Biomech. 1993; 26: 427-438
        • Schultz A.B.
        • Warwick D.N.
        • Berkson M.H.
        • et al.
        Mechanical properties of human lumbar spine motion segments: I. Responses in flexion, extension, lateral bending, and torsion.
        J Biomech Eng. 1979; 101 (Ref Type: Abstract): 46-52
        • Eijkelkamp M.F.
        • van Donkelaar C.C.
        • Veldhuizen A.G.
        • et al.
        Requirements for an artificial intervertebral disc.
        Int J Artif Organs. 2001; 24: 311-321
        • Steffen T.
        • Rubin R.K.
        • Baramki H.G.
        • et al.
        A new technique for measuring lumbar segmental motion in vivo. Method, accuracy, and preliminary results.
        Spine. 1997; 22: 156-166
        • Bible J.E.
        • Simpson A.K.
        • Emerson J.W.
        • et al.
        Quantifying the effects of degeneration and other patient factors on lumbar segmental range of motion using multivariate analysis.
        Spine. 2008; 33: 1793-1799
        • Quint U.
        • Wilke H.J.
        Grading of degenerative disk disease and functional impairment: imaging versus patho-anatomical findings.
        Eur Spine J. 2008; 17: 1705-1713
        • Mimura M.
        • Panjabi M.M.
        • Oxland T.R.
        • et al.
        Disc degeneration affects the multidirectional flexibility of the lumbar spine.
        Spine. 1994; 19: 1371-1380
        • Zhao F.
        • Pollintine P.
        • Hole B.D.
        • et al.
        Discogenic origins of spinal instability.
        Spine. 2005; 30: 2621-2630
        • Panjabi M.M.
        The stabilizing system of the spine. Part II. Neutral zone and instability hypothesis.
        J Spinal Disord. 1992; 5: 390-657
      2. Havey R, Voronov L, Gaitanis I, et al. Relaxation response of lumbar spine segments undergoing annular distraction: Implications to anterior lumbar interbody implant stability. 50th annual meeting of the Orthopaedic Research Society; March 2004; San Francisco, CA.

        • Wilke H.J.
        • Jungkunz B.
        • Wenger K.
        • et al.
        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. 1998; 251: 15-19
      3. Lipman J, Campbell D, Girardi F, et al. Mechanical behavior of the ProDisc II intervertebral disc prosthesis in human cadaveric spines. 49th Annual Meeting of the Orthopaedic Research Society, February 2–5, 2003, New Orleans, LA.

        • O'Leary P.
        • Nicolakis M.
        • Lorenz M.A.
        • et al.
        Response of Charite total disc replacement under physiologic loads: prosthesis component motion patterns.
        Spine J. 2005; 5: 590-599
        • Cunningham B.W.
        • Dmitriev A.E.
        • Hu N.
        • et al.
        General principles of total disc replacement arthroplasty: seventeen cases in a nonhuman primate model.
        Spine. 2003; 28: S118-S124
        • Panjabi M.
        • Henderson G.
        • Abjornson C.
        • et al.
        Multidirectional testing of one- and two-level ProDisc-L versus simulated fusions.
        Spine. 2007; 32: 1311-1319
        • Huang R.C.
        • Girardi F.P.
        • Cammisa Jr., F.P.
        • et al.
        The implications of constraint in lumbar total disc replacement.
        J Spinal Disord Tech. 2003; 16: 412-417
        • McAfee P.C.
        • Cunningham B.W.
        • Hayes V.
        • et al.
        Biomechanical analysis of rotational motions after disc arthroplasty: implications for patients with adult deformities.
        Spine. 2006; 31: S152-S160