Locking the Taylor Spatial Frame – The effect of three additional longitudinal rods on osteotomy site movements.


      • The Taylor Spatial Frame shows an element of laxity around neutral loading.
      • The laxity leads to a notable amount of osteotomy gap movement.
      • Not only axial, but bending, shear and rotational movements have been measured.
      • Additional longitudinal rods effectively eliminate the instability of the construct.



      In clinical practice, even when the fixator is locked, a noticeable laxity of the construct can be observed. This study was designed to measure the stiffness of the fixator and to analyze the movements of the osteotomy site. Furthermore, the effect of three additional longitudinal rods on the locking of the construct was analyzed.


      Five synthetic tibia/fixator models (Model A) were tested under rotational torque (40 Nm) and axial compression (700 N). Three additional rigid rods were subsequently mounted, and the tests were repeated (Model B). The movements of the fixator as well as the osteotomy site were registered by a digital optical measurement system. Load- deformation curves, and so stiffness of the models, were calculated and compared.


      Under rotational and axial loadings, Model A was found to be less rigid than Model B (p = 0.034; p = 0.194). Notably, Model A showed a region of laxity around neutral rotational (ΔF = 5 Nm) and axial (ΔF = 16.64 N) loading before a linear deformation trend was measured. Concomitantly, greater osteotomy site movement was measured for Model A than for Model B under full loading (p = 0.05) and within the region of increased laxity (p = 0.042).


      The fixator showed an element of laxity around neutral axial and rotational loading, which transferred to the bone and led to a notable amount of osteotomy gap movement. Mounting three additional rods increased the stiffness of the construct and therefore reduced the movement of the osteotomy site.


      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 Clinical Biomechanics
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Augat P.
        • Burger J.
        • Schorlemmer S.
        • Henke T.
        • Peraus M.
        • Claes L.
        Shear movement at the fracture site delays healing in a diaphyseal fracture model.
        J. Orthop. Res. 2003; 21: 1011-1017
        • Baran O.
        • Havitcioglu H.
        • Tatari H.
        • Cecen B.
        The stiffness characteristics of hybrid Ilizarov fixators.
        J. Biomech. 2008; 41: 2960-2963
        • Becerikli M.
        • Jaurich H.
        • Schira J.
        • Schulte M.
        • Dobele C.
        • Wallner C.
        • et al.
        Age-dependent alterations in osteoblast and osteoclast activity in human cancellous bone.
        J. Cell. Mol. Med. 2017; 21: 2773-2781
        • Bishop N.E.
        • Schneider E.
        • Ito K.
        An experimental two degrees-of-freedom actuated external fixator for in vivo investigation of fracture healing.
        Med. Eng. Phys. 2003; 25: 335-340
        • Bishop N.E.
        • van Rhijn M.
        • Tami I.
        • Corveleijn R.
        • Schneider E.
        • Ito K.
        Shear does not necessarily inhibit bone healing.
        Clin. Orthop. Relat. Res. 2006; 443: 307-314
        • Carter D.R.
        • Beaupre G.S.
        • Giori N.J.
        • Helms J.A.
        Mechanobiology of skeletal regeneration.
        Clin. Orthop. Relat. Res. 1998; S41-55
        • Claes L.E.
        • Heigele C.A.
        Magnitudes of local stress and strain along bony surfaces predict the course and type of fracture healing.
        J. Biomech. 1999; 32: 255-266
        • Claes L.E.
        • Wilke H.J.
        • Augat P.
        • Rubenacker S.
        • Margevicius K.J.
        Effect of dynamization on gap healing of diaphyseal fractures under external fixation.
        Clin. Biomech. (Bristol, Avon). 1995; 10: 227-234
        • Claes L.
        • Augat P.
        • Suger G.
        • Wilke H.J.
        Influence of size and stability of the osteotomy gap on the success of fracture healing.
        J. Orthop. Res. 1997; 15: 577-584
        • Claes L.
        • Augat P.
        • Schorlemmer S.
        • Konrads C.
        • Ignatius A.
        • Ehrnthaller C.
        Temporary distraction and compression of a diaphyseal osteotomy accelerates bone healing.
        J. Orthop. Res. 2008; 26: 772-777
        • Duda G.N.
        • Sollmann M.
        • Sporrer S.
        • Hoffmann J.E.
        • Kassi J.P.
        • Khodadadyan C.
        • et al.
        Interfragmentary motion in tibial osteotomies stabilized with ring fixators.
        Clin. Orthop. Relat. Res. 2002; 163-72
        • Eidelman M.
        • Katzman A.
        Treatment of complex tibial fractures in children with the Taylor spatial frame.
        Orthopedics. 2008; 31
        • Epari D.R.
        • Kassi J.P.
        • Schell H.
        • Duda G.N.
        Timely fracture-healing requires optimization of axial fixation stability.
        J. Bone Joint Surg. Am. 2007; 89: 1575-1585
        • Fenton C.
        • Henderson D.
        • Samchukov M.
        • Cherkashin A.
        • Sharma H.
        Comparative stiffness characteristics of Ilizarov- and hexapod-type external frame constructs.
        Strat. Trauma Limb. Reconstr. 2021; 16: 138-143
        • Gessmann J.
        • Citak M.
        • Jettkant B.
        • Schildhauer T.A.
        • Seybold D.
        The influence of a weight-bearing platform on the mechanical behavior of two Ilizarov ring fixators: tensioned wires vs. half-pins.
        J. Orthop. Surg. Res. 2011; 6: 61
        • Henderson D.J.
        • Rushbrook J.L.
        • Stewart T.D.
        • Harwood P.J.
        What are the biomechanical effects of half-pin and fine-wire configurations on fracture site movement in circular frames?.
        Clin. Orthop. Relat. Res. 2016; 474: 1041-1049
        • Henderson D.J.
        • Rushbrook J.L.
        • Harwood P.J.
        • Stewart T.D.
        What are the biomechanical properties of the Taylor spatial frame?.
        Clin. Orthop. Relat. Res. 2017; 475: 1472-1482
        • Kenwright J.
        • Goodship A.E.
        Controlled mechanical stimulation in the treatment of tibial fractures.
        Clin. Orthop. Relat. Res. 1989; 36-47
        • Khalily C.
        • Voor M.J.
        • Seligson D.
        Fracture site motion with Ilizarov and “hybrid” external fixation.
        J. Orthop. Trauma. 1998; 12: 21-26
        • Lacroix D.
        • Prendergast P.J.
        A mechano-regulation model for tissue differentiation during fracture healing: analysis of gap size and loading.
        J. Biomech. 2002; 35: 1163-1171
        • Marangoz S.
        • Feldman D.S.
        • Sala D.A.
        • Hyman J.E.
        • Vitale M.G.
        Femoral deformity correction in children and young adults using Taylor spatial frame.
        Clin. Orthop. Relat. Res. 2008; 466: 3018-3024
        • Martyniuk B.
        • Morasiewicz P.
        • Wudarczyk S.
        • Dragan S.F.
        • Filipiak J.
        The impact of configuration of the Ilizarov fixator on its stiffness and the degree of loading of distraction rods.
        Clin. Biomech. 2019; 63: 79-84
        • McKibbin B.
        The biology of fracture healing in long bones.
        J. Bone Joint Surg. (Br.). 1978; 60-B: 150-162
        • Moazen M.
        • Calder P.
        • Koroma P.
        • Wright J.
        • Taylor S.
        • Blunn G.
        An experimental evaluation of fracture movement in two alternative tibial fracture fixation models using a vibrating platform.
        Proc. Inst. Mech. Eng. H. 2019; 233: 595-599
        • Rozbruch R.S.
        • Segal K.
        • Ilizarov S.
        • Fragomen A.T.
        • Ilizarov G.
        Does the Taylor spatial frame accurately correct Tibial deformities?.
        Clin. Orthop. Relat. Res. 2010; 468: 1352-1361
        • Schenk R.K.
        • Willenegger H.R.
        Histology of primary bone healing: modifications and limits of recovery of gaps in relation to extent of the defect (author’s transl).
        Unfallheilkunde. 1977; 80: 155-160
        • Tan B.
        • Shanmugam R.
        • Gunalan R.
        • Chua Y.
        • Hossain G.
        • Saw A.
        A biomechanical comparison between Taylor’s spatial frame and Ilizarov external fixator.
        Malays. Orthop. J. 2014; 8: 35-39
        • Tan B.
        • Shanmugam R.
        • Gunalan R.
        • Chua Y.
        • Hossain G.
        • Saw A.
        A biomechanical comparison between Taylor’s spatial frame and Ilizarov external fixator.
        Malays. Orthop. J. 2014; 8: 35-39
        • Thiart G.
        • Herbert C.
        • Sivarasu S.
        • Gasant S.
        • Laubscher M.
        Influence of different connecting rod configurations on the stability of the Ilizarov/TSF frame: a biomechanical study.
        Strat. Trauma Limb. Reconstr. 2020; 15: 23-27
        • Wagner J.M.
        • Jaurich H.
        • Wallner C.
        • Abraham S.
        • Becerikli M.
        • Dadras M.
        • et al.
        Diminished bone regeneration after debridement of posttraumatic osteomyelitis is accompanied by altered cytokine levels, elevated B cell activity, and increased osteoclast activity.
        J. Orthop. Res. 2017; 35: 2425-2434
        • Wagner J.M.
        • Schmidt S.V.
        • Dadras M.
        • Huber J.
        • Wallner C.
        • Dittfeld S.
        • et al.
        Inflammatory processes and elevated osteoclast activity chaperon atrophic non-union establishment in a murine model.
        J. Transl. Med. 2019; 17: 416
        • Wolf S.
        • Janousek A.
        • Pfeil J.
        • Veith W.
        • Haas F.
        • Duda G.
        • et al.
        The effects of external mechanical stimulation on the healing of diaphyseal osteotomies fixed by flexible external fixation.
        Clin. Biomech. (Bristol, Avon). 1998; 13: 359-364