The effects of locking inserts and overtorque on the mechanical properties of a large fragment locking compression plate

• Published in: Journal of experimental orthopaedics 2021-11, Vol.8 (1), p.106-106, Article 106
• Main Authors: Meyers, Kathleen N., Achor, Timothy S., Prasarn, Mark L., Ahn, Jaimo, Khalsa, Kevin, Wellman, David S., Lorich, Dean G., Helfet, David L.
• Format: Article
• Language: English
• Subjects: Biomechanics; Failure; Fractures; Locking compression plate; Locking inserts; Locking plate; Mechanical properties; Mechanical testing; Medicine; Medicine & Public Health; Original Paper; Orthopedics; Overtorque; Surgeons; Surgical Orthopedics
• ISSN: 2197-1153; 2197-1153
• DOI: 10.1186/s40634-021-00424-0

Purpose The study was to determine the effect of locking hole inserts and their insertion torque on the fatigue life of a large fragment Locking Compression Plate (LCP) under bending forces. Methods Fatigue strength of the LCP was examined using cyclic three-point bend testing at 80% yield strength of the construct. Locking hole inserts were used in 2, 4, and 6-hole of a 12-hole plate to simulate three different working lengths. Within each working length, plates were tested without locking inserts serving as the control group. In the experimental groups, inserts were tightened to manufacturer recommendations (4 Nm) and using overtorque (8 Nm). Results Significantly fewer cycles to failure were observed in control groups versus the locking hole insert groups for all working lengths (2-hole: 4 Nm p  = 0.003, 8 Nm p  = 0.003; 4-hole: 4 Nm p  = 0.02, 8 Nm p