Headless Screw Fixation of Metacarpal Neck Fractures: A Mechanical Comparative Analysis.
K-wire fixation
headless compression screw fixation
mechanical study
metacarpal neck fractures
metacarpal plating
Journal
Hand (New York, N.Y.)
ISSN: 1558-9455
Titre abrégé: Hand (N Y)
Pays: United States
ID NLM: 101264149
Informations de publication
Date de publication:
03 2019
03 2019
Historique:
pubmed:
22
9
2017
medline:
25
2
2020
entrez:
22
9
2017
Statut:
ppublish
Résumé
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. 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. 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. 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.
Sections du résumé
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.
Identifiants
pubmed: 28933187
doi: 10.1177/1558944717731859
pmc: PMC6436118
doi:
Types de publication
Comparative Study
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
187-192Références
Instr Course Lect. 2006;55:121-8
pubmed: 16958445
Arch Orthop Trauma Surg. 2003 Dec;123(10):534-7
pubmed: 14639483
J Hand Microsurg. 2016 Dec;8(3):134-139
pubmed: 27999455
J Hand Surg Am. 2015 Aug;40(8):1586-90
pubmed: 25980734
Clin Orthop Relat Res. 1992 Mar;(276):194-201
pubmed: 1537152
J Hand Surg Am. 2014 Dec;39(12):2390-5
pubmed: 25240434
J Trauma. 2006 Apr;60(4):841-3
pubmed: 16612306
J Orthop Surg Res. 2011 Jun 07;6:27
pubmed: 21645410
Hand (N Y). 2013 Dec;8(4):454-9
pubmed: 24426966
J Hand Surg Br. 2004 Aug;29(4):374-6
pubmed: 15234503
Hand (N Y). 2014 Mar;9(1):16-23
pubmed: 24570632
Hand (N Y). 2008 Dec;3(4):311-5
pubmed: 18780019
Strategies Trauma Limb Reconstr. 2008 Sep;3(2):49-56
pubmed: 18766429
Hand (N Y). 2015 Mar;10(1):94-9
pubmed: 25767426
J Hand Surg Am. 2014 Sep;39(9):1722-7
pubmed: 25034789
J Hand Surg Am. 2013 Sep;38(9):1728-34
pubmed: 23809468
Hand (N Y). 2007 Dec;2(4):212-7
pubmed: 18780055
Orthop Surg. 2015 Aug;7(3):256-60
pubmed: 26311101
Hand Clin. 1997 Nov;13(4):557-71
pubmed: 9403293
J Hand Surg Am. 2010 Aug;35(8):1260-3
pubmed: 20619555
J Hand Surg Am. 2013 Feb;38(2):322-330.e2
pubmed: 23200214
J Hand Surg Am. 1995 May;20(3 Pt 2):S86-90
pubmed: 7642956
J Hand Surg Eur Vol. 2016 Nov;41(9):990-994
pubmed: 27464583
J Hand Surg Br. 2001 Jun;26(3):261-3
pubmed: 11386781
Orthop Traumatol Surg Res. 2010 Sep;96(5):506-12
pubmed: 20580630
Hand Clin. 1994 Feb;10(1):111-6
pubmed: 8188771
J Hand Surg Am. 2015 Apr;40(4):692-700
pubmed: 25661294
J Hand Surg Am. 1998 Sep;23(5):827-32
pubmed: 9763256