Imperial College London

ProfessorAndrewAmis

Faculty of EngineeringDepartment of Mechanical Engineering

Professor
 
 
 
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Contact

 

+44 (0)20 7594 7062a.amis

 
 
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Assistant

 

Ms Fabienne Laperche +44 (0)20 7594 7033

 
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Location

 

713City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Willmott:2018:10.1016/j.fas.2017.03.001,
author = {Willmott, H and Al-Wattar, Z and Halewood, C and Dunning, M and Amis, A},
doi = {10.1016/j.fas.2017.03.001},
journal = {Foot and Ankle Surgery},
pages = {259--263},
title = {Evaluation of different shape-memory staple configurations against crossed screws for first metatarsophalangeal joint arthrodesis: A biomechanical study},
url = {http://dx.doi.org/10.1016/j.fas.2017.03.001},
volume = {24},
year = {2018}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - BACKGROUND: The first metatarsophalangeal joint may be fused in order to treat arthritis or instability. The use of shape-memory staples for fixation is well recognised, but little work has been done into the optimal configuration of staples. METHODS: The structural behaviour of first metatarsophalangeal joint (MTPJ) arthrodeses using shape-memory staples or crossed screws was studied using cadaveric porcine joints. Five fixation configurations were tested: single vertical or horizontal staple, paired staples in dorsal-medial configuration (0-90° to the sagittal plane), paired staples in oblique orthogonal configuration (45-135°); or two crossed screws. Specimens were loaded in cyclical dorsiflexion for 1000 cycles. Plantar gapping and shearing were measured. Specimens were then loaded to failure. RESULTS: Cyclic testing caused more shear in the 45-135° staples than the crossed screws (1.0mm±0.5mm compared to 0.14mm±0.4mm, p<0.01). No significant difference was found in plantar gap formation. Single vertical and horizontal single staples failed at 15N and 19. CONCLUSIONS: N, respectively. Paired 0-90° staples failed at 43N±9N, significantly lower than the 45-135° staples (141N±25N; p<0.001) and crossed screws (180N±67N; p<0.001). There was no significant difference between the 45-135° staples and crossed screws. Screws failed by sudden cortical fracture; staples displayed gradual pull-out and shearing. First MTPJ arthrodeses fixed with single staples are not recommended. Arthrodeses fixed with staples at 0-90° to the sagittal plane were significantly less strong than two crossed screws. However, positioning oblique staples at 45-135° significantly improved stability, creating a construct as strong as, crossed screws. None of the constructs was strong enough for immediate weight bearing.
AU - Willmott,H
AU - Al-Wattar,Z
AU - Halewood,C
AU - Dunning,M
AU - Amis,A
DO - 10.1016/j.fas.2017.03.001
EP - 263
PY - 2018///
SN - 1268-7731
SP - 259
TI - Evaluation of different shape-memory staple configurations against crossed screws for first metatarsophalangeal joint arthrodesis: A biomechanical study
T2 - Foot and Ankle Surgery
UR - http://dx.doi.org/10.1016/j.fas.2017.03.001
UR - https://www.ncbi.nlm.nih.gov/pubmed/29409249
UR - http://hdl.handle.net/10044/1/60912
VL - 24
ER -