1. Palmer RH. Biological osteosynthesis. Vet Clin North Am Small Anim Pract 1999;29:1171–1185.
2. Strauss EJ, Schwarzkopf R, Kummer F, et al. The current status of locked plating: the good, the bad, and the ugly. J Orthop Trauma 2008;22:479–486.
3. Borrelli J Jr, Prickett W, Song E, et al. Extraosseous blood supply of the tibia and the effects of different plating techniques: a human cadaveric study. J Orthop Trauma 2002;16:691–695.
4. Garofolo S, Pozzi A. Effect of plating technique on periosteal vasculature of the radius in dogs: a cadaveric study. Vet Surg 2013;42:255–261.
5. Gautier E, Sommer C. Guidelines for the clinical application of the LCP. Injury 2003;34(suppl 2):B63–B76.
6. Voss K, Kull MA, Hässig M, et al. Repair of long-bone fractures in cats and small dogs with the Unilock mandible locking plate system. Vet Comp Orthop Traumatol 2009;22:398–405.
7. Haaland PJ, Sjöström L, Devor M, et al. Appendicular fracture repair in dogs using the locking compression plate system: 47 cases. Vet Comp Orthop Traumatol 2009;22:309–315.
8. Nicetto T, Petazzoni M, Urizzi A, et al. Experiences using the Fixin locking plate system for the stabilization of appendicular fractures in dogs: a clinical and radiographic retrospective assessment. Vet Comp Orthop Traumatol 2013;26:61–68.
9. Barnhart MD, Rides CF, Kennedy SC, et al. Fracture repair using a polyaxial locking plate system (PAX). Vet Surg 2013;42:60–66.
10. Vallefuoco R, Le Pommellet H, Savin A, et al. Complications of appendicular fracture repair in cats and small dogs using locking compression plates. Vet Comp Orthop Traumatol 2016;29:46–52.
11. Johnson SJ, von Pfeil DJF, Déjardin LM, et al. Internal fracture fixation. In: Johnson SJ, Tobias KM, eds. Veterinary surgery small animal. 2nd ed. St Louis: Elsevier, 2018;654–690.
12. Boero Baroncelli A, Reif U, Bignardi C, et al. Effect of screw insertion torque on push-out and cantilever bending properties of five different angle-stable systems. Vet Surg 2013;42:308–315.
13. Hurt RJ, Syrcle JA, Elder S, et al. A biomechanical comparison of unilateral and bilateral String-of-Pearls™ locking plates in a canine distal humeral metaphyseal gap model. Vet Comp Orthop Traumatol 2014;27:186–191.
14. Kim SE, Lewis DD. Corrective osteotomy for procurvatum deformity caused by distal femoral physeal fracture malunion stabilised with String-of-Pearls locking plates: results in two dogs and a review of the literature. Aust Vet J 2014;92:75–80.
15. Ness MG. Repair of Y-T humeral fractures in the dog using paired ‘String of Pearls’ locking plates. Vet Comp Orthop Traumatol 2009;22:492–497.
16. Early P, Mente P, Dillard S, et al. In vitro biomechanical evaluation of internal fixation techniques on the canine lumbosacral junction. PeerJ 2015;3:e1094.
17. Demianiuk RM, Benamou J, Rutherford S, et al. Effect of screw type and distribution on the torsional stability of 3.5 mm string of pearls locking plate constructs. Vet Surg 2015;44:119–125.
18. Goh CSS, Santoni BG, Puttlitz CM, et al. Comparison of the mechanical behaviors of semicontoured, locking plate-rod fixation and anatomically contoured, conventional plate-rod fixation applied to experimentally induced gap fractures in canine femora. Am J Vet Res 2009;70:23–29.
19. Boulton CL, Kim H, Shah SB, et al. Do locking screws work in plates bent at holes? J Orthop Trauma 2014;28:189–194.
20. Ioannou C, Knight M, Daniele L, et al. Effectiveness of the surgical torque limiter: a model comparing drill- and hand-based screw insertion into locking plates. J Orthop Surg Res 2016;11:118.
21. Tremolada G, Lewis DD, Paragnani KL, et al. Biomechanical comparison of a 3.5-mm conical coupling plating system and a 3.5-mm locking compression plate applied as plate-rod constructs to an experimentally created fracture gap in femurs of canine cadavers. Am J Vet Res 2017;78:712–717.
22. Chao P, Conrad BP, Lewis DD, et al. Effect of plate working length on plate stiffness and cyclic fatigue life in a cadaveric femoral fracture gap model stabilized with a 12-hole 2.4 mm locking compression plate. BMC Vet Res 2013;9:125.
23. Field EJ, Parsons K, Etches JA, et al. Effect of monocortical and bicortical screw numbers on the properties of a locking plate-intramedullary rod configuration. An in vitro study on a canine femoral fracture gap model. Vet Comp Orthop Traumatol 2016;29:459–465.
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To compare mechanical properties (stiffness, yield load, failure load, and deformation at failure) of 2 pearl-type locking plate system (PLS) constructs (PLS 1 and PLS 2) in a simulated fracture gap model and to compare screw push-out forces of the 2 PLSs with and without plate contouring.
40 PLS constructs.
Mechanical properties of uncontoured PLS 1 (n = 8) and PLS 2 (8) constructs were evaluated in synthetic bone-plate models under axial compression. Screw push-out forces were evaluated in 6 uncontoured and 6 contoured PLSs of each type. Variables of interest were compared between PLS groups and between contoured and uncontoured plates by statistical methods.
Yield and failure loads were higher in the PLS 1 group than in the PLS 2 group, but stiffness did not differ significantly between groups. All constructs failed by plate bending, with greater deformation in the PLS 2 group. Push-out force to screw-plate uncoupling was higher in the PLS 2 group than in the PLS 1 group for uncontoured and contoured plates. Locking mechanism failure of PLS 1 specimens was through screw-thread stripping. The PLS 2 specimens failed by node deformation followed by screwhead stripping.
Distinct mechanical differences were identified between the 2 PLSs. The clinical relevance of these differences is unknown. Further research including cyclic fatigue testing is needed to reveal more clinically pertinent information.