Single cycle to failure in torsion of three standard and five locking plate constructs

Summary

Objectives: The biomechanical properties of standard plates and recently designed locking plates were compared in torsion. We hypothesized that titanium (Ti) constructs would have the greatest deformation, and String of Pearls (SOP) constructs the greatest strength and stiffness.

Methods: Dynamic compression plates (DCP), stainless steel (SS) limited contact (LC)-DCP, Ti LC-DCP, locking compression plate (LCP), 10 mm and 11 mm Advanced Locking Plate System (ALPS) 10 and 11, SOP and Fixin plates were applied to a validated bone model simulating a bridging osteosynthesis. Yield torque (strength), yield angle (deformation) and stiffness were compared using one-way ANOVA with post hoc Tukey (p <0.05).

Results: The ALPS 11 constructs had significantly greater elastic deformation than all constructs except for the ALPS 10. There were not any differences in strength observed except for the ALPS 10 constructs, which was less than that for the SOP, LCP, DCP and ALPS 11 constructs. No differences in construct torsional stiffness were observed with the SS LCDCP, DCP, LCP and SOP constructs however all had greater stiffness than all remaining constructs. The ALPS 10 construct had lower stiffness than all constructs.

Clinical significance: Modulus of elasticity of Ti explains the higher deformation and lower stiffness of these systems, with similar results for the Fixin due to its lower section modulus compared to all other plates. The SOP and standard constructs had surprisingly similar biomechanical properties in torsion. The rationale for selecting these implants for fracture repair likely needs to be based upon their differing biomechanical properties inherent to the diverse implant systems.

Presented at the 38^th Annual Conference of the Veterinary Orthopedic Society, Snowmass, Colorado, USA March 6, 2011.

Keywords

Torsion - bone plates - locking plates - in vitro - plate failure

• References

• 1 Perren SM. Evolution of the internal fixation of long bone fractures. The scientific basis of biological internal fixation: choosing a new balance between stability and biology. J Bone Jt Surg 2002; 84 B 1093-1110.
• 2 Rozbruch SR, Muller U, Gautier E. et al The evolution of femoral shaft plating technique. Clin Orthop Rel Res 1998; 354: 195-208.
• 3 Miclau T, Martin RE. The evolution of modern plate osteosynthesis. Injury 1997; 28 (Suppl. 01) A3-A6.
• 4 Guiot LP, Dejardin LM. Prospective evaluation of minimally invasive plate osteosynthesis in 36 nonarticular tibial fractures in dogs and cats. Vet Surg 2011; 40: 171-182.
• 5 Arens S, Schlegel U, Printzen G. et al Influence of materials for fixation implants on local infection. An experimental study of steel versus titanium DCP in rabbits. J Bone Joint Surg 1996; 78 B 647-651.
• 6 Imam MA, Fraker AC. Titanium alloys as implant materials. In: Brown SA, Lemons JE, editors. Medical Applications of Titanium and its Alloys: The Material and Biological Issues, ASTM STP 1272. West Conshohocken, PA, USA: American Society of Testing Materials; 1996: 3-16.
• 7 Perren SM, Cordey J, Rahn BA. et al Early temporary porosis of bone induced by internal fixation implants. A reaction to necrosis, not to stress protection?. Clin Orthop Rel Res 1988; 232: 139-151.
• 8 Jain R, Podworny N, Hupel TM. et al Influence of plate design on cortical bone perfusion and fracture healing in canine segmental tibial fractures. J Orthop Trauma 1999; 13: 178-186.
• 9 Tepic S, Remiger AR, Morikawa H. et al Strength recovery in fractured sheep tibia treated with a plate or an internal fixator: An experimental study with a two-year follow-up. J Orthop Trauma 1997; 11: 14-23.
• 10 Johnson AL, Houlton JE, Vannini R. AO Principles of Fracture Management in the Dog and Cat. New York: Thieme; 2005
• 11 DeTora M, Kraus K. Mechanical testing of 3.5 mm locking and non-locking bone plates. Vet Comp Orthop Traumatol 2008; 21: 318-322.
• 12 Hammel SP, Pluhar EG, Novo RE. et al Fatigue analysis of plates used for fracture stabilization in small dogs and cats. Vet Surg 2006; 35: 573-578.
• 13 Zahn K, Frei R, Wunderle D. et al Mechanical properties of 18 different AO bone plates and the clamp-rod internal fixation system tested on a gap model construct. Vet Comp Orthop Traumatol 2008; 21: 185-194.
• 14 Aguila AZ, Manos JM, Orlansky AS. et al In vitro biomechanical comparison of limited contat dynamic compression plate and locking compression plate. Vet Comp Orthop Traumatol 2005; 18: 220-226.
• 15 Filipowicz D, Lanz O, McLaughlin R. et al A bio-mechanical comparison of 3.5 locking compression plate fixation to 3.5 limited contact dynamic compression plate fixation in a canine cadaveric distal humeral metaphyseal gap model. Vet Comp Orthop Traumatol 2009; 22: 270-277.
• 16 Acker ML, Torrance B, Kowaleski MP. et al Structural properties of synthetic bone models compared to native canine bone. Proceedings of the 19th Annual Scientific Meeting of the European College of Veterinary Surgeons; 2010 July 1–3 Helsinki, Finland: 2010: 150-151.
• 17 Matter P, Burch HB. Clinical experience with titanium implants, especially with the limited contact dynamic compression plate system. Arch Orthop Trauma Surg 1990; 109: 311-313.
• 18 Perren SM. The concept of biological plating using the limited contact-dynamic compression plate (LC-DCP). Scientific background, design and application. Injury 1991; 22 (Suppl. 01) 1-41.
• 19 Jain R, Podworny N, Hearn T. et al A biomechanical evaluation of different plates for fixation of canine radial osteotomies. J Trauma 1998; 44: 193-197.
• 20 Blake CA, Boudrieau RJ, Torrance BS. et al Single cycle to failure in bending of three standard and five locking plates and plate constructs. Vet Comp Orthop Traumatol 2011; 24: 408-417.
• 21 Serhan H, Slivka M, Albert T. et al Is galvanic corrosion between titanium alloy and stainless steel spinal implants a clinical concern?. Spine J 2004; 4: 379-387.
• 22 Hol PJ, Molster A, Gjerdet NR. Should the galvanic combination of titanium and stainless steel surgical implants be avoided?. Injury 2008; 39: 161-169.
• 23 Baroncelli A, Reif U, Bignardi C. Effect of screw insertional torque on push-out strength in 5 different angular stable systems. Proceedings from the 2010 World Veterinary Orthopedic Conference. 0Bologna, Italy: 2010. September 15–18 542-543.
• 24 American Society for Testing and Materials. Standard Test Method for Static Bending Properties of Metallic Bone Plates, ASTM F382-86. In: 1994 Annual Book for ASTM Standards. West Conshohocken, PA: ASTM. 1994: 57-60.
• 25 Miclau T, Remiger A, Tepic S. et al A mechanical comparison of the dynamic compression plate, limited contact-dynamic compression plate, and point contact fixator. J Orthop Trauma 1995; 9: 17-22.
• 26 Sod GA, Riggs LM, Mitchell CF. et al An in vitro biomechanical comparison of a 5.5 mm locking compression plate fixation with a 4.5 mm locking compression plate fixation of osteotomized equine third metacarpal bones. Vet Surg 2010; 39: 581-587.
• 27 Haerdi-Landerer C, Steiner A, Linke B. et al Comparison of double dynamic compression plating versus two configurations of an internal veterinary fixation device: Results of in vitro mechanical testing using a bone substitute. Vet Surg 2002; 31: 582-588.
• 28 Abel EW, Sun J. Mechanical evaluation of a new minimum-contact plate for internal fracture fixation. J Orthop Trauma 1998; 12: 382-386.
• 29 Gautier E, Perren SM, Cordey J. Strain distribution in plated and unplated sheep tibia an in vivo experiment. Injury 2000; 31 (Suppl. 03) C37-C44.
• 30 Stoffel K, Klaue K, Perren SM. Functional load of plates in fracture fixation in vivo and its correlate in bone healing. Injury 2000; 31 (Suppl. 02) S-B37-B50.