Vet Comp Orthop Traumatol
DOI: 10.1055/s-0044-1790209
Original Research

Comparison of Bending Stiffness between String of Pearls Plate-Bone Substitute Constructs with and without Bending Tees in a Fracture Gap Model

Pei-Han Lu
1   Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, United States
,
1   Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, United States
,
Ramsis Farag
2   Center of Polymers and Advanced Composites, College of Engineering, Auburn University, Auburn, Alabama, United States
,
Erik H. Hofmeister
1   Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, United States
,
Kendon Kuo
1   Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, United States
,
Brad M. Matz
1   Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, United States
› Author Affiliations

Abstract

Objective The aim of this study was to compare the bending properties of String of Pearls plate-bone substitute constructs with and without bending tees in the nodes over a simulated fracture gap. It is hypothesized that the constructs with tees will have higher bending stiffness.

Study Design Acetal polymer tubes and 12-hole, 3.5-mm String of Pearls plates were used to create plate-bone substitute constructs simulating stabilization in a bridging fashion over a 45-mm gap. Twenty-four constructs were made with 12 containing tees in the nodes over the fracture gap. Single-cycle load-to-failure 4-point bending was performed in mediolateral and craniocaudal planes. Bending stiffness was compared with a t-test (p < 0.05).

Results All plate-bone substitute constructs had a permanent loss of structural integrity via plastic deformation of the plate. The bending stiffness (mean ± standard deviation) of the craniocaudal group was 59.11 ± 1.98 N/mm with tees and 59.25 ± 1.69 N/mm without tees (p = 0.88). In the mediolateral group, the bending stiffness was 43.17 ± 0.75 N/mm with tees and 41.09 ± 0.91 N/mm without tees (p = 0.0042).

Conclusion In 4-point bending, the plate-bone substitute constructs with tees had equivalent bending stiffness in the craniocaudal plane and increased bending stiffness in the mediolateral plane. However, with a small absolute difference in values, the clinical significance is unclear. Future studies for cyclic bending, torsional, and axial compression tests should be performed to further investigate the value of tees in the nodes over a comminuted or gap fracture repaired in a bridging fashion.

Note

Content from this study was presented as an abstract at the Veterinary Orthopedic Society Annual Conference; March 11–18, 2023; Big Sky, Montana.


Authors' Contribution

P.-H.L. and K.M.C. contributed to the conception, study design, acquisition of data, data analysis and interpretation. R.F. contributed to acquisition of data, data analysis and interpretation. E.H. contributed to the study design, data analysis and interpretation. K.K. contributed to study design. B.M. contributed to the conception and study design. All authors drafted, revised, and approved the submitted manuscript and are publicly responsible for the relevant content.




Publication History

Received: 30 September 2023

Accepted: 09 August 2024

Article published online:
20 September 2024

© 2024. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

 
  • References

  • 1 Ness MG. The effect of bending and twisting on the stiffness and strength of the 3.5 SOP implant. Vet Comp Orthop Traumatol 2009; 22 (02) 132-136
  • 2 DeTora M, Kraus K. Mechanical testing of 3.5 mm locking and non-locking bone plates. Vet Comp Orthop Traumatol 2008; 21 (04) 318-322
  • 3 Benamou J, Demianiuk RM, Rutherford S. et al. Effect of bending direction on the mechanical behaviour of 3.5 mm String-of-Pearls and Limited Contact Dynamic Compression Plate constructs. Vet Comp Orthop Traumatol 2015; 28 (06) 433-440
  • 4 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 (06) 408-417
  • 5 Field MR, Butler R, Wills RW, Maxwell WM. Retrospective evaluation of perioperative and short term clinical outcomes in appendicular long bone skeleton fractures repaired via the string of pearls (SOP) locking plate system. BMC Vet Res 2018; 14 (01) 386
  • 6 Kumar KM, Prasad VD, Lakshmi ND, Raju NKB. Management of distal femoral diaphyseal fractures with string of pearls locking plate in dogs. Indian J Anim Res 2018; 52: 1757-1761
  • 7 Reddy GVAK, Kumar VG, Raghavendera KBP, Kumar DP. Use of String of Pearls locking plate system for stabilization of femoral fractures in canines. Int J Livest Res 2020; 10 (10) 92-98
  • 8 Eayrs MK, Guerin V, Grierson J, Moores AP. Repair of fractures of the lateral aspect of the humeral condyle in skeletally mature dogs with locking and non-locking plates. Vet Comp Orthop Traumatol 2021; 34 (06) 419-426
  • 9 Ness MG. Repair of Y-T humeral fractures in the dog using paired 'String of Pearls' locking plates. Vet Comp Orthop Traumatol 2009; 22 (06) 492-497
  • 10 Grand JG. Use of string-of-pearls locking implants for the stabilisation of acetabular and supra-acetabular fractures in three dogs. Revue Vét Clin 2016; 51: 35-41
  • 11 Piana F, Solano M, Kalff S, Yeadon R. Locking plate fixation for canine acetabular fractures. Vet Comp Orthop Traumatol 2020; 33 (04) 294-300
  • 12 Sadan MA, Fischer A, Bokemeyer J, Kramer M. Surgical repair of ilial fractures in dogs and cats using string of pearls (SOP)-plate. Indian J Vet Surg 2015; 36 (01) 41-45
  • 13 Segal U, Bar H, Shani J. Repair of lumbosacral fracture-luxation with bilateral twisted string-of-pearls locking plates. J Small Anim Pract 2018; 59: 501-507
  • 14 Fitzpatrick N, Nikolaou C, Yeadon R, Hamilton M. String-of-pearls locking plate and cerclage wire stabilization of periprosthetic femoral fractures after total hip replacement in six dogs. Vet Surg 2012; 41 (01) 180-188
  • 15 Tremolada G, Taggart R, Lewis DD, Palmer RH, Lambrechts NE. An assessment of mechanical properties and screw push-out for two 3.5-mm pearl-type locking plate systems. Am J Vet Res 2019; 80 (06) 533-538
  • 16 Hurt RJ, Syrcle JA, Elder S, McLaughlin R. 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 (03) 186-191
  • 17 Hutcheson KD, Butler JR, Elder SE. Comparison of double locking plate constructs with single non-locking plate constructs in single cycle to failure in bending and torsion. Vet Comp Orthop Traumatol 2015; 28 (04) 234-239
  • 18 Cabassu JB, Kowaleski MP, Skorinko JK, Blake CA, Gaudette GR, Boudrieau RJ. Single cycle to failure in torsion of three standard and five locking plate constructs. Vet Comp Orthop Traumatol 2011; 24 (06) 418-425
  • 19 Pearson T, Glyde M, Hosgood G, Day R. The effect of intramedullary pin size and monocortical screw configuration on locking compression plate-rod constructs in an in vitro fracture gap model. Vet Comp Orthop Traumatol 2015; 28 (02) 95-103
  • 20 Orthomed. SOP™ Interlocking Plate System User Guide. Accessed August 20, 2024 at: www.orthomed.co.uk
  • 21 ANSI. Standard Specification and Test Method for Metallic Bone Plates. ASTM F382-17. West Conshohocken, PA: 2022
  • 22 Muir P, Johnson KA, Markel MD. Area moment of intertia for comparison of implant cross-sectional geometry and bending stiffness. Vet Comp Orthop Traumatol 1995; 8: 146-152
  • 23 Team Bone. The Foundation for Interpreting Local Load History Using Bone Histomorphology. Accessed April 27, 2022 at: https://teambone.com/education-basic/biomechanics-of-bone/
  • 24 Malenfant RC, Sod GA. In vitro biomechanical comparison of 3.5 string of pearl plate fixation to 3.5 locking compression plate fixation in a canine fracture gap model. Vet Surg 2014; 43 (04) 465-470
  • 25 Hyndman P, Worth AJ, Clark K. The effect of pearl spacing on single-cycle load-to-failure and cyclic loading parameters of 2.0 mm pearl locking plates. N Z Vet J 2021; 69 (06) 337-342
  • 26 Rutherford S, Ness MG. Effect of contouring on bending structural stiffness and bending strength of the 3.5 titanium SOP implant. Vet Surg 2012; 41 (08) 983-987
  • 27 Cohen L, Dean M, Shipov A, Atkins A, Monsonego-Ornan E, Shahar R. Comparison of structural, architectural and mechanical aspects of cellular and acellular bone in two teleost fish. J Exp Biol 2012; 215 (Pt 11): 1983-1993