Vet Comp Orthop Traumatol 2014; 27(03): 186-191
DOI: 10.3415/VCOT-13-10-0133
Original Research
Schattauer GmbH

A biomechanical comparison of unilateral and bilateral String-of-Pearls™ locking plates in a canine distal humeral metaphyseal gap model

R. J. Hurt
1   Mississippi State University, College of Veterinary Medicine, Mississippi State, MS, USA
,
J. A. Syrcle
1   Mississippi State University, College of Veterinary Medicine, Mississippi State, MS, USA
,
S. Elder
1   Mississippi State University, College of Veterinary Medicine, Mississippi State, MS, USA
,
R. McLaughlin
1   Mississippi State University, College of Veterinary Medicine, Mississippi State, MS, USA
› Author Affiliations
Further Information

Publication History

Received 28 October 2013

Accepted 11 March 2014

Publication Date:
21 December 2017 (online)

Summary

Objective: To compare the in vitro biomechanical performance of two String-of-Pearls (SOP) plate constructs in a canine distal humeral metaphyseal gap model.

Methods: Seven pairs of canine cadaveric humeri, including the elbow joints, were prepared. One group consisted of a unilateral medially placed SOP plate with bicortical screws (UNI). The second group consisted of bilateral caudo-medial and caudo-lateral SOP plates applied with monocortical screws (BI). A 2 cm ostectomy was performed immediately proximal to the supratrochlear foramen. Constructs were tested in torsion and axial compression.

Results: The UNI constructs had significantly lower stiffness in torsion and axial compression than the BI group. However, UNI constructs had a significantly higher ultimate strength than BI constructs. All UNI constructs failed by bending of the transcondylar screw and SOP plate. All BI constructs failed by axial pullout of the distal most screws.

Clinical significance: In stabilizing canine supracondylar humeral fractures as modeled here, both the UNI model and the BI model demonstrated biomechanical advantages. The incorporation of a transcondylar screw through the medial plate appears to be beneficial to construct strength.

 
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