Double-Screw Osteosynthesis in an Unstable Scaphoid Fracture Model: A Biomechanical Comparison of Two Screw Configurations

Surke, Carsten; Huntington, Lachlan S.; Zhang, Xingshuo; Ek, Eugene T.H.; Ackland, David; Tham, Stephen K. (2021). Double-Screw Osteosynthesis in an Unstable Scaphoid Fracture Model: A Biomechanical Comparison of Two Screw Configurations (In Press). Journal of hand surgery - American volume Elsevier 10.1016/j.jhsa.2021.08.019

[img] Text
1-s2.0-S0363502321005505-main.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (925kB) | Request a copy

Purpose: Although there is evidence that a single headless compression screw is sufficient for fixation of most scaphoid fractures, double-screw osteosynthesis has been shown to result in higher failure strength and stiffness than a single screw. However, the biomechanical effect of different screw configurations has not been determined.

Methods: A standardized unstable fracture model was produced in 28 cadaveric scaphoids. Specimens were randomly allocated to 1 of 2 fixation groups using 2 internal compression screws positioned in either the sagittal or coronal plane. A specimen-specific 3-dimensionally-printed customized screw placement and osteotomy device was developed using computer-aided design-generated models derived from computed tomography scan data of each individual scaphoid. Load to failure and stiffness of the repair constructs were evaluated using a mechanical testing system.

Results: There were no significant differences in size, weight, and density between the scaphoid specimens. The average distance between screws was significantly greater in the sagittal group than in the coronal group. There were no significant differences between the coronal and sagittal aligned double screws in load to 2 mm displacement (mean coronal 180.9 ± 109.7 N; mean sagittal 156.0 ± 85.8 N), load to failure (mean coronal 275.9 ± 150.6 N; mean sagittal 248.0 ± 109.5 N), stiffness (mean coronal 111.7 ± 67.3 N/mm; mean sagittal 101.2 ± 45.1 N/mm), and energy absorption (mean coronal 472.6 ± 261.4 mJ; mean sagittal 443.5 ± 272.7 mJ).

Conclusions: There are no significant biomechanical differences between the sagittal or coronal aligned double headless compression screws in a scaphoid fracture model with bone loss.

Clinical relevance: In cases where double-screw fixation of the scaphoid is being considered, the placement of double screws can be at the discretion of the surgeon, and can be dictated by ease of access, surgical preference, and fracture orientation.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Department of Orthopaedic, Plastic and Hand Surgery (DOPH) > Clinic of Plastic and Hand Surgery > Hand Surgery
04 Faculty of Medicine > Department of Orthopaedic, Plastic and Hand Surgery (DOPH) > Clinic of Plastic and Hand Surgery

UniBE Contributor:

Surke, Carsten

Subjects:

600 Technology > 610 Medicine & health

ISSN:

0363-5023

Publisher:

Elsevier

Language:

English

Submitter:

Veronika Picha

Date Deposited:

11 Nov 2021 09:36

Last Modified:

12 Nov 2021 00:13

Publisher DOI:

10.1016/j.jhsa.2021.08.019

PubMed ID:

34690014

BORIS DOI:

10.48350/160385

URI:

https://boris.unibe.ch/id/eprint/160385

Actions (login required)

Edit item Edit item
Provide Feedback