Clinical Orthopaedics and Related Research®

, Volume 471, Issue 3, pp 1039–1044 | Cite as

Locking Buttons Increase Fatigue Life of Locking Plates in a Segmental Bone Defect Model

  • Marc Tompkins
  • David J. Paller
  • Douglas C. Moore
  • Joseph J. Crisco
  • Richard M. Terek
Basic Research



Durability of plate fixation is important in delayed union. Although locking plates result in stronger constructs, it is not known if locking affects the fatigue life of a plate. Two locking screws on either side of the nonunion could decrease working length and increase strain in the plate. However, the reinforcing effect of the locking head on the plate may compensate, so that it is unclear whether locking reduces fatigue life.


We determined whether locking screws, compression screws, and locking buttons reduce or increase the fatigue life of a plate.


We tested fatigue life of four constructs using an eight-hole locking plate in a segmental defect model: (1) all locking screws (Locked; n = 5); (2) all compression screws (Unlocked; n = 5); (3) six compression screws with two locking buttons in the central holes (Button; n = 6); and (4) six compression screws with two open central holes (Open; n = 6).


The Button group had the longest fatigue life (1.3 million cycles). There was no difference between the Locked and Unlocked groups. All of the constructs failed by fracture of the plates through a screw hole adjacent to the defect.


Locking screws did not improve fatigue life, however a locking button increased the fatigue life of a locking plate in a segmental bone defect model.

Clinical Relevance

Locking buttons in holes adjacent to a defect may improve durability, which is important when delayed union is a possibility.



We thank Allison Biercevicz BS and Ryan Rich for assistance with testing the samples.


  1. 1.
    ASTM International. ASTM Standard F382-99 Standard Specification and Test Method for Metallic Bone Plates. ASTM International, West Conshohocken, PA, 2008. DOI:  10.1520/F0382-99R08E01. Available at: Accessed October 11, 2012.
  2. 2.
    Bellapianta J, Dow K, Pallotta NA, Hospodar PP, Uhl RL, Ledet EH. Threaded screw head inserts improve locking plate biomechanical properties. J Orthop Trauma. 2011;25:65–71.PubMedCrossRefGoogle Scholar
  3. 3.
    Bergmann G, Deuretzbacher G, Heller M, Graichen F, Rohlmann A, Strauss J, Duda GN. Hip contact forces and gait patterns from routine activities. J Biomech. 2001;34:859–871.PubMedCrossRefGoogle Scholar
  4. 4.
    Berrey BH Jr, Lord CF, Gebhardt MC, Mankin HJ. Fractures of allografts: frequency, treatment, and end-results. J Bone Joint Surg Am. 1990;72:825–833.PubMedGoogle Scholar
  5. 5.
    Buecker PJ, Berenstein M, Gebhardt MC, Hornicek FJ, Mankin HJ. Locking versus standard plates for allograft fixation after tumor resection in children and adolescents. J Pediatr Orthop. 2006;26:680–685.PubMedCrossRefGoogle Scholar
  6. 6.
    Chong AC, Friis EA, Ballard GP, Czuwala PJ, Cooke FW. Fatigue performance of composite analogue femur constructs under high activity loading. Ann Biomed Eng. 2007;35:1196–1205.PubMedCrossRefGoogle Scholar
  7. 7.
    Chong AC, Miller F, Buxton M, Friis EA. Fracture toughness and fatigue crack propagation rate of short fiber reinforced epoxy composites for analogue cortical bone. J Biomech Eng. 2007;129:487–493.PubMedCrossRefGoogle Scholar
  8. 8.
    Cristofolini L, Viceconti M. Mechanical validation of whole bone composite tibia models. J Biomech. 2000;33:279–288.PubMedCrossRefGoogle Scholar
  9. 9.
    Cristofolini L, Viceconti M, Cappello A, Toni A. Mechanical validation of whole bone composite femur models. J Biomech. 1996;29:525–535.PubMedCrossRefGoogle Scholar
  10. 10.
    Duda GN, Schneider E, Chao EY. Internal forces and moments in the femur during walking. J Biomech. 1997;30:933–941.PubMedCrossRefGoogle Scholar
  11. 11.
    Egol KA, Kubiak EN, Fulkerson E, Kummer FJ, Koval KJ. Biomechanics of locked plates and screws. J Orthop Trauma. 2004;18:488–493.PubMedCrossRefGoogle Scholar
  12. 12.
    Firoozabadi R, McDonald E, Nguyen TQ, Buckley JM, Kandemir U. Does plugging unused combination screw holes improve the fatigue life of fixation with locking plates in comminuted supracondylar fractures of the femur? J Bone Joint Surg Br. 2012;94:241–248.PubMedCrossRefGoogle Scholar
  13. 13.
    Fulkerson E, Egol KA, Kubiak EN, Liporace F, Kummer FJ, Koval KJ. Fixation of diaphyseal fractures with a segmental defect: a biomechanical comparison of locked and conventional plating techniques. J Trauma. 2006;60:830–835.PubMedCrossRefGoogle Scholar
  14. 14.
    Gardner MJ, Brophy RH, Campbell D, Mahajan A, Wright TM, Helfet DL, Lorich DG. The mechanical behavior of locking compression plates compared with dynamic compression plates in a cadaver radius model. J Orthop Trauma. 2005;19:597–603.PubMedCrossRefGoogle Scholar
  15. 15.
    Gardner MJ, Silva MJ, Krieg JC. Biomechanical testing of fracture fixation constructs: variability, validity, and clinical applicability. J Am Acad Orthop Surg. 2012;20:86–93.PubMedCrossRefGoogle Scholar
  16. 16.
    Gautier E, Sommer C. Guidelines for the clinical application of the LCP. Injury. 2003;34(suppl 2):B63–76.PubMedCrossRefGoogle Scholar
  17. 17.
    Gerrand CH, Griffin AM, Davis AM, Gross AE, Bell RS, Wunder JS. Large segment allograft survival is improved with intramedullary cement. J Surg Oncol. 2003;84:198–208.PubMedCrossRefGoogle Scholar
  18. 18.
    Heiner AD, Brown TD. Structural properties of a new design of composite replicate femurs and tibias. J Biomech. 2001;34:773–781.PubMedCrossRefGoogle Scholar
  19. 19.
    Hertel R, Eijer H, Meisser A, Hauke C, Perren SM. Biomechanical and biological considerations relating to the clinical use of the Point Contact-Fixator: evaluation of the device handling test in the treatment of diaphyseal fractures of the radius and/or ulna. Injury. 2001;32(suppl 2):B10–14.PubMedCrossRefGoogle Scholar
  20. 20.
    Hoffmeier KL, Hofmann GO, Muckley T. Choosing a proper working length can improve the lifespan of locked plates: a biomechanical study. Clin Biomech (Bristol, Avon). 2011;26:405–409.Google Scholar
  21. 21.
    Hornicek FJ, Gebhardt MC, Tomford WW, Sorger JI, Zavatta M, Menzner JP, Mankin HJ. Factors affecting nonunion of the allograft-host junction. Clin Orthop Relat Res. 2001;382:87–98.PubMedCrossRefGoogle Scholar
  22. 22.
    Jazrawi LM, Kummer FJ, Simon JA, Bai B, Hunt SA, Egol KA, Koval KJ. New technique for treatment of unstable distal femur fractures by locked double-plating: case report and biomechanical evaluation. J Trauma. 2000;48:87–92.PubMedCrossRefGoogle Scholar
  23. 23.
    Kaiser MM, Wessel LM, Zachert G, Stratmann C, Eggert R, Gros N, Schulze-Hessing M, Kienast B, Rapp M. Biomechanical analysis of a synthetic femur spiral fracture model: influence of different materials on the stiffness in flexible intramedullary nailing. Clin Biomech (Bristol, Avon). 2011;26:592–597.Google Scholar
  24. 24.
    Kanchanomai C, Muanjan P, Phiphobmongkol V. Stiffness and endurance of a locking compression plate fixed on fractured femur. J Appl Biomech. 2010;26:10–16.PubMedGoogle Scholar
  25. 25.
    Koval KJ, Hoehl JJ, Kummer FJ, Simon JA. Distal femoral fixation: a biomechanical comparison of the standard condylar buttress plate, a locked buttress plate, and the 95-degree blade plate. J Orthop Trauma. 1997;11:521–524.PubMedCrossRefGoogle Scholar
  26. 26.
    Kubiak EN, Fulkerson E, Strauss E, Egol KA. The evolution of locked plates. J Bone Joint Surg Am. 2006;88(suppl 4):189–200.PubMedCrossRefGoogle Scholar
  27. 27.
    Morlock M, Schneider E, Bluhm A, Vollmer M, Bergmann G, Muller V, Honl M. Duration and frequency of every day activities in total hip patients. J Biomech. 2001;34:873–881.PubMedCrossRefGoogle Scholar
  28. 28.
    Niemeyer P, Sudkamp NP. Principles and clinical application of the locking compression plate (LCP). Acta Chir Orthop Traumatol Cech. 2006;73:221–228.PubMedGoogle Scholar
  29. 29.
    Ogilvie CM, Crawford EA, Hosalkar HS, King JJ, Lackman RD. Long-term results for limb salvage with osteoarticular allograft reconstruction. Clin Orthop Relat Res. 2009;467:2685–2690.PubMedCrossRefGoogle Scholar
  30. 30.
    Perren SM. Evolution and rationale of locked internal fixator technology: introductory remarks. Injury. 2001;32(suppl 2):B3–9.PubMedCrossRefGoogle Scholar
  31. 31.
    Seide K, Triebe J, Faschingbauer M, Schulz AP, Puschel K, Mehrtens G, Jurgens Ch. Locked vs. unlocked plate osteosynthesis of the proximal humerus: a biomechanical study. Clin Biomech (Bristol, Avon). 2007;22:176–182.Google Scholar
  32. 32.
    Smith WR, Ziran BH, Anglen JO, Stahel PF. Locking plates: tips and tricks. J Bone Joint Surg Am. 2007;89:2298–2307.PubMedCrossRefGoogle Scholar
  33. 33.
    Sommer C, Gautier E, Muller M, Helfet DL, Wagner M. First clinical results of the Locking Compression Plate (LCP). Injury. 2003;34(suppl 2):B43–54.PubMedCrossRefGoogle Scholar
  34. 34.
    Sorger JI, Hornicek FJ, Zavatta M, Menzner JP, Gebhardt MC, Tomford WW, Mankin HJ. Allograft fractures revisited. Clin Orthop Relat Res. 2001;382:66–74.PubMedCrossRefGoogle Scholar
  35. 35.
    Stoffel K, Dieter U, Stachowiak G, Gachter A, Kuster MS. Biomechanical testing of the LCP: how can stability in locked internal fixators be controlled? Injury. 2003;34(suppl 2):B11–19.PubMedCrossRefGoogle Scholar
  36. 36.
    Sugiura H, Katagiri H, Yonekawa M, Sato K, Yamamura S, Iwata H. Walking ability and activities of daily living after limb salvage operations for malignant bone and soft-tissue tumors of the lower limbs. Arch Orthop Trauma Surg. 2001;121:131–134.PubMedCrossRefGoogle Scholar
  37. 37.
    Taylor SJ, Walker PS, Perry JS, Cannon SR, Woledge R. The forces in the distal femur and the knee during walking and other activities measured by telemetry. J Arthroplasty. 1998;13:428–437.PubMedCrossRefGoogle Scholar
  38. 38.
    Taylor WR, Heller MO, Bergmann G, Duda GN. Tibio-femoral loading during human gait and stair climbing. J Orthop Res. 2004;22:625–632.PubMedCrossRefGoogle Scholar
  39. 39.
    Toy PC, White JR, Scarborough MT, Enneking WF, Gibbs CP. Distal femoral osteoarticular allografts: long-term survival, but frequent complications. Clin Orthop Relat Res. 2010;468:2914–2923.PubMedCrossRefGoogle Scholar
  40. 40.
    Vander Griend RA. The effect of internal fixation on the healing of large allografts. J Bone Joint Surg Am. 1994;76:657–663.Google Scholar
  41. 41.
    Walsh S, Reindl R, Harvey E, Berry G, Beckman L, Steffen T. Biomechanical comparison of a unique locking plate versus a standard plate for internal fixation of proximal humerus fractures in a cadaveric model. Clin Biomech (Bristol, Avon). 2006;21:1027–1031.Google Scholar

Copyright information

© The Association of Bone and Joint Surgeons® 2012

Authors and Affiliations

  • Marc Tompkins
    • 1
  • David J. Paller
    • 2
  • Douglas C. Moore
    • 2
  • Joseph J. Crisco
    • 2
  • Richard M. Terek
    • 2
  1. 1.Department of Orthopaedic SurgeryUniversity of MinnesotaMinneapolis USA
  2. 2.Department of OrthopaedicsThe Warren Alpert Medical School of Brown University and Rhode Island Hospital ProvidenceUSA

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