Headless Screw Fixation of Metacarpal Neck Fractures: A Mechanical Comparative Analysis
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Authors
Jones, Christopher M.
Padegimas, Eric M.
Weikert, Nicole
Greulich, Samuel
Ilyas, Asif M.
Siegler, Sorin
Issue Date
2017
Type
journal-article
Language
Keywords
Metacarpal neck fractures , Headless compression screw fixation , Mechanical study , K-wire fixation , Metacarpal plating
Alternative Title
Abstract
Background: The purpose of this study was to compare the mechanical properties of metacarpal neck fracture fixation by headless compression screw (HCS) with that of Kirschner wire (KW) cross-pinning and locking plate (LP) fixation. Methods: A metacarpal neck fracture was created in 30 fourth-generation composite Sawbones metacarpal models. A volar-based wedge was removed using a custom jig to simulate a typical apex dorsal fracture, unstable in flexion. The models were divided into 3 equal groups based on the method of fixation: retrograde cross-pinning with two 1.2-mm KWs, 2.0-mm dorsal T-plate with six 2.0-mm locking screws (LP), and a 3.0-mm retrograde HCS. Models were fixed at the proximal end, mounted in a material testing machine, and loaded through a cable tensioned over the metacarpal head, simulating grip loading. Cyclic loading from 0 to 40 N was performed, followed by loading to failure. Load, displacement, and failure mode were recorded. Results: Stiffness of the HCS (7.3 ± 0.7 N/m) was significantly greater than the KW (5.8 ± 0.5 N/m) but significantly less than the LP (9.5 ± 1.9 N/m). With cyclic loading to 40 N, the LP exhibited significantly less displacement (0.2 ± 1.3 mm) compared with the HCS (2.5 ± 2.3 mm) and KW (2.8 ± 1.0 mm). Load to failure for the HCS (215.5 ±3 9.0 N) was lower than that of the KW (279.7 ± 100.3 N) and of the LP (267.9 ± 44.1 N), but these differences were not statistically significant. Conclusions: The HCS provided mechanical fracture fixation properties comparable with KW fixation. The LP construct allowed significantly less displacement and had the highest strength of the 3 fixation methods.
Description
Citation
Jones CM, Padegimas EM, Weikert N, Greulich S, Ilyas AM, Siegler S. Headless Screw Fixation of Metacarpal Neck Fractures: A Mechanical Comparative Analysis. HAND. 2019;14(2):187-192. doi:10.1177/1558944717731859
Publisher
HAND
License
Journal
Volume
Issue
PubMed ID
ISSN
1558-9447
1558-9455
1558-9455