International Orthopaedics

, Volume 37, Issue 7, pp 1341–1346 | Cite as

Anterior internal fixator versus a femoral distractor and external fixation for sacroiliac joint compression and single stance gait testing: a mechanical study in synthetic bone

  • Jonathan M. Vigdorchik
  • Amanda O. Esquivel
  • Xin Jin
  • King H. Yang
  • Rahul Vaidya
Original Paper



The purpose of this study was to evaluate the biomechanical stability and compressive forces across the sacroiliac (SI) joint of an anterior internal fixator compared to the femoral distractor and external fixator for vertically unstable pelvic fractures.


Five composite pelvises with a simulated APC type III injury fixed with a femoral distractor, external fixator, or anterior internal fixator were tested. A pressure-sensitive film (Tekscan) was placed in the disrupted SI joint recording the magnitude of force. Then, in a single-leg stance model (Instron machine), a load was applied through the sacrum. We recorded displacement at the pubic symphysis and SI joint using high-speed video. Peak load and displacement were measured, and axial stiffness was calculated. Values were compared using a Student’s t-test (p < 0.05).


The SI joint was compressed significantly (p < 0.001) more using the anterior internal fixator (18.9 N) and femoral distractor (18.6 N) than the two-pin external fixator (2.5 N). There was no significant difference between the anterior internal fixator and the femoral distractor in displacement at the SI joint. The pubic symphysis displaced less with the femoral distractor than the anterior internal fixator (5.5 mm vs. 4.1 mm; p < 0.05).


The anterior pedicle screw internal fixator allows for indirect compression across the sacroiliac joint that is superior to two-pin external fixation and comparable to the femoral distractor. The anterior internal fixator may be an option for temporary anterior pelvic fixation in situations where external fixation or the femoral distractor have otherwise been used.


Conflict of interest

Ther authors declare that they have no conflict of interest in the preparation of this publication. We also declare that Dr. Vaidya has received payment for lectures from AO Trauma and Synthes Trauma for teaching courses; Dr. Vaidya has received payments for consulting with Stryker Corporation for implant development; and Dr. Vaidya is involved in developing an FDA approved product for Stryker Corporation which is not this fixator that is made from custom spinal implants.

The institution of the authors has received funding from Synthes for the testing materials used in this study through a research grant.The FDA has not approved the devices used for the purposes described in this manuscript.


  1. 1.
    Burgess AR, Eastridge BJ, Young JW et al (1990) Pelvic ring disruptions: effective classification system and treatment protocols. J Trauma 30(7):848–856PubMedCrossRefGoogle Scholar
  2. 2.
    Tile M (1995) Fractures of the pelvis and acetabulum, 2nd edn. Williams & Wilkins, BaltimoreGoogle Scholar
  3. 3.
    Riemer BL, Butterfield SL, Diamond DL et al (1993) Acute mortality associated with injuries to the pelvic ring: the role of early patient mobilization and external fixation. J Trauma 35(5):671–675PubMedCrossRefGoogle Scholar
  4. 4.
    Gardner MJ, Nork SE (2007) Stabilization of unstable pelvic fractures with supraacetabular compression external fixation. J Orthop Trauma 21(4):269–273PubMedCrossRefGoogle Scholar
  5. 5.
    Giannoudis PV, Pape HC (2004) Damage control orthopaedics in unstable pelvic ring injuries. Injury 35(7):671–677PubMedCrossRefGoogle Scholar
  6. 6.
    Sagi HC, Ordway NR, DiPasquale T (2004) Biomechanical analysis of fixation for vertically unstable sacroiliac dislocations with iliosacral screws and symphyseal plating. J Orthop Trauma 18(3):138–143PubMedCrossRefGoogle Scholar
  7. 7.
    Vaidya R, Kubiak EN, Bergin PF et al (2012) Complications of anterior subcutaneous internal fixation for unstable pelvis fractures: a multicenter study. Clin Orthop Relat Res 470(8):2124–2131PubMedCrossRefGoogle Scholar
  8. 8.
    Mason WT, Khan SN, James CL, Chesser TJ, Ward AJ (2005) Complications of temporary and definitive external fixation of pelvic ring injuries. Injury 36(5):599–604PubMedCrossRefGoogle Scholar
  9. 9.
    Gardner MJ, Kendoff D, Ostermeier S, Citak M, Hüfner T, Krettek C, Nork SE (2007) Sacroiliac joint compression using an anterior pelvic compressor: a mechanical study in synthetic bone. J Orthop Trauma 1(7):435–441CrossRefGoogle Scholar
  10. 10.
    Vaidya R, Colen R, Vigdorchik J, Tonnos F, Sethi A (2012) Treatment of unstable pelvic ring injuries with an internal anterior fixator and posterior fixation: initial clinical series. J Orthop Trauma 26(1):1–8PubMedCrossRefGoogle Scholar
  11. 11.
    Chong AC, Miller F, Buxton M, Friis EA (2007) Fracture toughness and fatigue crack propagation rate of short fiber reinforced epoxy composites for analogue cortical bone. J Biomech Eng 129(4):487–493PubMedCrossRefGoogle Scholar
  12. 12.
    Heiner AD (2008) Structural properties of fourth-generation composite femurs and tibias. J Biomech 41(15):3282–3284PubMedCrossRefGoogle Scholar
  13. 13.
    Zdero R, Olsen M, Bougherara H, Schemitsch EH (2008) Cancellous bone screw purchase: a comparison of synthetic femurs, human femurs, and finite element analysis. Proc Inst Mech Eng Pt H J Eng Med 222(8):1175–1183CrossRefGoogle Scholar
  14. 14.
    Clements JP, Moriaty N, Chesser TJ, Ward AJ, Cunningham JL (2008) Determination of pelvic ring stability: a new technique using a composite hemi-pelvis. Proc Inst Mech Eng Pt H J Eng Med 222(5):611–616CrossRefGoogle Scholar
  15. 15.
    MacAvoy MC, McClellan RT, Goodman SB, Chien CR, Allen WA, van der Meulen MC (1997) Stability of open-book pelvic fractures using a new biomechanical model of single-limb stance. J Orthop Trauma 11(8):590–593PubMedCrossRefGoogle Scholar
  16. 16.
    Pohlemann T, Culemann U, Tscherne H (1992) Comparative biomechanical studies of internal stabilization of trans-foraminal sacrum fractures. Der Orthopade 21(6):413–421PubMedGoogle Scholar
  17. 17.
    Ponsen KJ, Joosse P, Van Dijke GA, Snijders CJ (2007) External fixation of the pelvic ring: an experimental study on the role of pin diameter, pin position, and parasymphyseal fixator pins. Acta Orthopaedica 78(5):648–653PubMedCrossRefGoogle Scholar
  18. 18.
    Pohlemann T, Angst M, Schneider E, Ganz R, Tscherne H (1993) Fixation of transforaminal sacrum fractures: a biomechanical study. J Orthop Trauma 7(2):107–117PubMedCrossRefGoogle Scholar
  19. 19.
    van Zwienen CM, van den Bosch EW, Hoek van Dijke GA, Snijders CJ, van Vugt AB (2005) Cyclic loading of sacroiliac screws in Tile C pelvic fractures. J Trauma 58(5):1029–1034PubMedCrossRefGoogle Scholar
  20. 20.
    van Zwienen CM, van den Bosch EW, Snijders CJ, Kleinrensink GJ, van Vugt AB (2004) Biomechanical comparison of sacroiliac screw techniques for unstable pelvic ring fractures. J Orthop Trauma 18(9):589–595PubMedCrossRefGoogle Scholar
  21. 21.
    Dujardin FH, Roussignol X, Hossenbaccus M, Thomine JM (2002) Experimental study of the sacroiliac joint micromotion in pelvic disruption. J Orthop Trauma 16(2):99–103PubMedCrossRefGoogle Scholar
  22. 22.
    Dujardin FH, Roussignol X, Hossenbaccus M, Thomine JM (2002) Experimental study of the sacroiliac joint micromotion in pelvic disruption. J Orthop Trauma 16(2):99–103PubMedCrossRefGoogle Scholar
  23. 23.
    Comstock CP, van der Meulen MC, Goodman SB (1996) Biomechanical comparison of posterior internal fixation techniques for unstable pelvic fractures. J Orthop Trauma 10(8):517–522PubMedCrossRefGoogle Scholar
  24. 24.
    Simonian PT, Routt ML Jr, Harrington RM, Tencer AF (1994) Internal fixation of the unstable anterior pelvic ring: a biomechanical comparison of standard plating techniques and the retrograde medullary superior pubic ramus screw. J Orthop Trauma 8(6):476–482PubMedGoogle Scholar
  25. 25.
    Varga E, Hearn T, Powell J, Tile M (1995) Effects of method of internal fixation of symphyseal disruptions on stability of the pelvic ring. Injur 26(2):75–80CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Jonathan M. Vigdorchik
    • 1
  • Amanda O. Esquivel
    • 1
  • Xin Jin
    • 2
  • King H. Yang
    • 2
  • Rahul Vaidya
    • 1
  1. 1.Orthopaedic Surgery, Detroit Medical Center, 4D4 University Health Center, Detroit Receiving HospitalWayne State UniversityDetroitUSA
  2. 2.Biomedical EngineeringWayne State UniversityDetroitUSA

Personalised recommendations