Jnl Wrist Surg 2019; 08(04): 280-287
DOI: 10.1055/s-0039-1683845
Scientific Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Impact of Design on Force between Flexor Tendons and Distal Radius Volar Plates

Katharine M. Hinchcliff
1  Division of Plastic Surgery, University of California–Davis Medical Center, Sacramento, California
,
Ido Volk
2  Department of Orthopedic Surgery, University of California–Davis Medical Center, Sacramento, California
,
Xenia Ivanova
2  Department of Orthopedic Surgery, University of California–Davis Medical Center, Sacramento, California
,
Sandra Taylor
3  Department of Public Health, University of California–Davis Medical Center, Sacramento, California
,
Robert M. Szabo
2  Department of Orthopedic Surgery, University of California–Davis Medical Center, Sacramento, California
› Author Affiliations
Funding The project described was supported by the National Center for Advancing Translational Sciences, National Institutes of Health (Grant # UL1 TR001860). Funding for the cadaver arms and plates was provided by a generous educational grant from Medartis.
Further Information

Publication History

27 October 2018

06 February 2019

Publication Date:
25 March 2019 (eFirst)

Abstract

Background Flexor tendon injury is a rare but serious complication of distal radius volar plating.

Purpose This study aims to determine whether the design of distal radius volar plates impacts the amount of force exerted on the flexor digitorum profundus (FDP) and flexor pollicis longus (FPL) tendons when the plates are placed proximal and distal to the watershed line.

Methods Three commercially available plates were applied to 10 fresh, matched-pair upper extremity specimens. Cyclical loading was applied to the tendons, and the force generated between tendon and plate was measured. Linear mixed effect models were used to evaluate differences in maximum and mean forces by plate position, plate design, and the interaction between position and design.

Results Forces on the tendons differed significantly by position but not plate design. For the FPL tendon, the average maximum force with a plate in Soong's grade 2 was 4.50 (95% confidence interval [CI]: 2.8–7.3) times higher than when the plate was in a Soong's grade 0 placement, and 4.63 (95% CI: 2.82–7.61) times higher for the FDP tendon. While not statistically significant, lower observed force values with thinner plates when plates were placed distal to the watershed line suggest that that plate thickness could also be a critical plate characteristic for distally placed plates.

Conclusion Despite differences in plate design, the main determinant of plate prominence and therefore flexor tendon injury potential is placement in relation to the watershed line.

Clinical Relevance This study may help to guide surgeon implant selection and volar plate design.

Note

This article, entitled “Impact of Design on Force between the Tendons and Distal Radius Volar Plates,” and its authors adhere to the ethical standards described by the Committee on Publication Ethics and the International Committee of Medical Journal Editors.


Authors' Contributions

Dr. K.M.H. is principally responsible for the experimental design, cadaver testing, and manuscript preparation. Dr. I.V. and Ms. X.I. assisted with experimental design and cadaver testing. Author X.I. additionally played a significant role in experimental design and execution, including motor and sensor calibration. Dr. S.T. was the principal statistician and is also responsible for [Fig. 4] and [Table 1]. Dr. R.M.S., as the senior author of this manuscript, provided invaluable guidance regarding experimental design, as well as critical manuscript editing. All of the authors have read and approved the final submitted manuscript.