Microtomographic morphometry of the stapedius muscle and its tendon

Tomasz Wojciechowski,Kazimierz Niemczyk,Jean-Gualbert Nève De Mévergnies,Tymon Skadorwa

doi:10.1007/s12565-019-00490-6

Abstract

The aim of this study was to evaluate the morphology of the stapedius muscle and its tendon with the use of microCT and to describe their anatomic relationship with facial nerve and incudostapedial joint. The study was performed on 16 fresh cadaveric temporal bones scanned in microtomography (microCT). Stapedius muscle and its tendon were identified in each set of images. The length of the medial and lateral border of the stapedius tendon (STL-med, STL-lat), width at the insertion to stapes (STW-s), at the point it emerges from the pyramidal eminence (STW-p) and in the half way from the pyramidal eminence to stapes (STW-m), and the length and the width of the belly of stapedius muscle (BSML and BSMW) were measured in modified axial plane. The shortest distance between the facial canal and incudostapedial joint (FN-isj), and between the facial canal and stapedius tendon (FN-st) were measured in the Pöschl plane. The average values of all distances measured were: STL-lat 1.29 ± 0.50 mm, STL-med 1.27 ± 0.44 mm, BSML 2.98 ± 0.51 mm, STW-s 0.47 ± 0.10 mm, STW-p 0.46 ± 0.12 mm, STW-m 0.35 ± 0.12 mm, BSMW 1.26 ± 0.29 mm, FN-isj 1.72 ± 0.33 mm, FN-st 1.35 ± 0.30 mm. The stapedius muscle complex consists of the tendon and the belly, and the border between them in microCT scans is not always evident. The distance between the facial nerve and the incudostapedial joint is greater than the distance between the facial nerve and the stapedius muscle tendon.

Highlights

The stapedius muscle is usually referred to as the smallest muscle in the human body
The development of stapedius muscle and its tendon has been the subject of very few articles, and even they refer to animals rather than to humans (Arensburg et al 1981; Borg et al 2009; van den Berge and van der Wal 1990)
Several authors still wonder whether to preserve the stapedius tendon during this procedure (Colletti et al 1988; Gros et al 2003) but not a single paper refers to the tendon morphology

Summary

Introduction

The stapedius muscle is usually referred to as the smallest muscle in the human body. A first detailed description of this structure and its tendon were delivered by Paaw (1615) in the early seventeenth century. The development of stapedius muscle and its tendon has been the subject of very few articles, and even they refer to animals rather than to humans (Arensburg et al 1981; Borg et al 2009; van den Berge and van der Wal 1990). Several authors still wonder whether to preserve the stapedius tendon during this procedure (Colletti et al 1988; Gros et al 2003) but not a single paper refers to the tendon morphology. It is striking that the professional literature still lacks a detailed

Objectives

Methods

Results

Discussion

Conclusion