The Effect of Dorsally Angulated Distal Radius Deformities on Carpal Kinematics: An In Vitro Biomechanical Study

Authors

Clare E. Padmore, St. Joseph's Health Care London
Helen Stoesser, St. Joseph's Health Care London
Masao Nishiwaki, St. Joseph's Health Care London
Braden Gammon, St. Joseph's Health Care London
G. Daniel G. Langohr, St. Joseph's Health Care London
Emily A. Lalone, St. Joseph's Health Care London
James A. Johnson, St. Joseph's Health Care London
Graham J.W. King, St. Joseph's Health Care London

Document Type

Article

Publication Date

11-1-2018

Journal

Journal of Hand Surgery

Volume

43

Issue

11

First Page

1036.e1

Last Page

1036.e8

URL with Digital Object Identifier

10.1016/j.jhsa.2018.02.017

Abstract

© 2018 American Society for Surgery of the Hand Purpose: The purpose was to quantify the effect of distal radius dorsal angulation (DA) on carpal kinematics and the relative roles of the radiocarpal and midcarpal joints during wrist motion. Methods: Six cadaveric specimens (69 ± 17 y) were mounted at 90° elbow flexion in a custom wrist motion simulator. The wrist was guided through planar passive flexion and extension motion trials (∼ 5°/s). A custom modular distal radius implant was used to simulate native alignment and 3 distal radius DA deformities (10° 20° 30°). An optical tracking system captured carpal bone motion, from which radiocarpal and midcarpal joint motion was determined. Results: The radiocarpal joint made a greater contribution to wrist motion than the midcarpal joint in flexion, and the midcarpal joint made a greater contribution to motion than the radiocarpal joint in wrist extension. Increasing DA caused the radiocarpal joint contribution to increase throughout the motion arc, with the effect being more pronounced in wrist flexion. Conversely, as DA increased, the midcarpal joint contributed less rotation to the total wrist motion and its overall motion arc decreased; the magnitude of effect was greater in wrist extension. Dorsal angulation resulted in increased lunate flexion with respect to the distal radius. Conclusions: Our findings agree with current literature that suggests that, in an uninjured wrist, the radiocarpal joint predominates flexion, and the midcarpal joint predominates extension. In addition, the radiocarpal joint has an amplified contribution in wrist flexion with greater DA malunion. Clinical relevance: The altered contributions of the radiocarpal and midcarpal joints may contribute to pain, stiffness, and the development of arthritis, which is commonly seen at the radiocarpal joint after malunion of the distal radius.

Notes

Article is freely available from the journal