Related Experiment Video
Updated: Jul 6, 2026

An Intramedullary Locking Nail for Standardized Fixation of Femur Osteotomies to Analyze Normal and Defective Bone Healing in Mice
Published on: November 13, 2016
Locked versus unlocked plating with respect to plate length in an ulna fracture model
David B Weiss1, Scott G Kaar, Elizabeth P Frankenburg
1Orthopaedic Surgery Associates, St. Joseph Mercy Hospital, Ypsilanti, Michigan, USA.
Objective:
Determine contributions of plate length and locked fixation in an ulna fracture.
Methods:
two groups of six pairs of ulnae were plated with a small-fragment LCP around a 1 cm ostectomy. Control specimens: eight-hole plate, three consecutive unlocked screws on each side. Experimental specimens: 10-hole plate, two screws (Group 1, Unlocked; Group 2, Locked) in near- far configuration on either side.
Outcomes:
Stiffness in torsion and 4-point bending stiffness and load at yield.
Results:
Unlocked: mean torsional stiffness (Ncm/deg) for the experimental and control specimens, 7.57 and 7.73, respectively (p > 0.05); mean bending stiffness (kN/m), 88.50 and 90.76, respectively (p > 0.05); and mean yield strength (kN), 1.06 and 0.89, respectively (p < 0.05). Locked: mean torsional stiffness for the experimental and control specimens, 7.10 and 8.27, re- spectively (p > 0.05); mean bending stiffness, 72.96 and 79.20, respectively (p > 0.05); and mean yield strength, 1.23 and 1.03, respectively (p > 0.05). Mean differences between the experimental and control specimens in tor- sion: Unlocked, 0.17; Locked, 1.17 (p > 0.05). Mean differences in bending stiffness: Unlocked, 2.25; Locked, 6.24 (p > 0.05). Mean differences in yield strength: Unlocked, 0.17; Locked, 0.21 (p > 0.05).
Conclusions:
Locked plating provided no mechanical advantage over unlocked plating. The use of a longer plate with unlocked screws increased yield strength.
More Related Videos
Related Concept Videos
Bones of the Upper Limb: Ulna
Bones of the Upper Limb: Radius
The radius has a nail-shaped head, and a short...
Fractures: Bone Repair
Minor fractures with no bone displacement are treated by immobilizing the fractured bone using a cast or splint. However, in the case of fractures with displaced bones, the broken bones are repositioned before immobilization to ensure successful healing without deformation and loss of function. The realignment of fractured bone ends is performed through a process called reduction. If the procedure...
Bones of the Upper Limb: Humerus

