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14th Triennial Congress of the International Federation of Societies for Surgery of the Hand (IFSSH), 11th Triennial Congress of the International Federation of Societies for Hand Therapy (IFSHT)

17.06. - 21.06.2019, Berlin

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Determination of correct length in total trapeziometacarpal arthroplasty

Meeting Abstract

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  • presenting/speaker Bram Van Hove - Ziekenhuis Oost-Limburg, VUB, Genk, Belgium
  • Amber Bruijnes - Ziekenhuis Oost-Limburg, VUB, Genk, Belgium
  • Pieter Caekebeke - Ziekenhuis Oost-Limburg, VUB, Genk, Belgium
  • Kristoff Corten - Ziekenhuis Oost-Limburg, VUB, Genk, Belgium
  • Ilse Degreef - KUL, Leuven, Belgium
  • Joris Duerinckx - Ziekenhuis Oost-Limburg, VUB, Genk, Belgium

International Federation of Societies for Surgery of the Hand. International Federation of Societies for Hand Therapy. 14th Triennial Congress of the International Federation of Societies for Surgery of the Hand (IFSSH), 11th Triennial Congress of the International Federation of Societies for Hand Therapy (IFSHT), 11th Triennial Congress of the International Federation of Societies for Hand Therapy (IFSHT). Berlin, 17.-21.06.2019. Düsseldorf: German Medical Science GMS Publishing House; 2020. DocIFSSH19-1280

doi: 10.3205/19ifssh1094, urn:nbn:de:0183-19ifssh10949

Published: February 6, 2020

© 2020 Van Hove et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.

Outline

Text

Objectives/Interrogation: The goal of this study is to examine the effect of increasing neck length on range of motion and stability of trapeziometacarpal total joint (TMC) arthroplasty. We want to determine the ideal neck length for optimal stability and motion.

Methods: This study is based on the analysis of 7 fresh-frozen human cadaveric forearms with no signs of TMC osteoarthritis.

Thumb length and range of motion were measured using a three-dimensional electromagnetic motion tracking device (Patriot system®, Polhemus). Sensor 1 was fixed on the head of the first metacarpal (MC) and sensor 2 on the distal phalanx of the thumb. Raw data was captured with PiMgr GUI and exported to MathLab.

All the tendons were individually loaded with a hanging weight of 1N (100g) to simulate muscle tone. Active movement was obtained by aditionally loading muscles. Positional data of both sensors was captured. This was first performed for the native TMC joint. Next, an Arpe TMC prosthesis (Zimmer Biomet) was implanted. Assessments were made for progressively longer necks: 0, +2, +4 and +6mm. We repeated each measurement 5 times for every excursion, and the mean of the five tests was used for analysis.

Data processing

1.
From the position of the head of the first MC (sensor 1), the center of motion (COM) of the TMC joint could be determined.
2.
The range of motion of the TMC joint in the planes flexion-extension and abduction-adduction was expressed as the angle formed by the line connecting the head of the first MC (sensor 1) and the COM.
3.
The range of motion of the distal phalanx was determined in the same way, but by using data of sensor 2.
4.
The distance between the COM and the first metacarpal head was calculated.

Statistics: The data was analyzed by repeated measures analysis of variance with post hoc Bonferroni analysis. The differences between different neck lengths were compared using the paired t-test.

Results and Conclusions: Thumb length was adequately reconstructed after implantation of a total joint implant with neutral neck length. With increasing neck length, range of motion of the trapeziometacarpal joint and the distal phalanx of the thumb decreased. Longitudinal stability of the TMC joint increased with increasing neck length.

By increasing prosthetic neck length, thumb range of motion decreased, while increasing the stability of the construct, as is intuitively assumable. We were able to determine a "sweet-spot" of optimal stability and range of motion. This information can guide the surgeon intra-operatively.