Triceps, quadriceps or pentaceps femoris? Need for proper muscle definition

• Published in: Morphologie 2020-05, Vol.104 (345), p.77-84
• Main Authors: Bonnechère, B., Louryan, S., Feipel, V.
• Format: Article
• Language: English
• Subjects: Adult; Anatomy, Cross-Sectional; Cadaver; Dissection; Extensor apparatus of the knee joint; Female; Humans; Male; Quadriceps femoris; Quadriceps Muscle - anatomy & histology; Tensor vastus intermedius; Terminology as Topic
• ISSN: 1286-0115
• DOI: 10.1016/j.morpho.2019.06.001

•Authors described a fifth head in the quadriceps.•This muscle, the tensor of vastus intermedius (TVI), would be present in all cases.•20 legs have been dissected.•We found TVI in only 7 legs.•Definition of a muscle, or head, is discussed in this paper. Over the last years, the definition of quadriceps femoris (QF) has evolved somewhat and some authors now define a fifth head: the tensor of vastus intermedius (TVI). Descriptions of the different components of QF in textbooks and recent findings remain confusing. Therefore, the aim of this study is to obtain more information on this possible fifth head. Twenty lower limbs of 10 embalmed cadavers, six females and four males, were investigated by macro-dissection. The dissection and separation of the different heads were performed with the fingers and a distinction between the different parts of the quadriceps was noted only if it was possible to separate the heads without scalpel to avoid artificial separation of muscle parts. In 9 lower limbs we found a QF as classically described in textbook. TVI was found in only 7 limbs and in 4 cases we were not able to differentiate VI and VM or VI and VL (triceps femoris as described by Testut). These results, and the diversity of descriptions found in the literature have led us to review the definition of an isolated muscle. In this study, the presence of TVI was not demonstrated in all limbs unlike previously published studies on the subject. Harmonisation of dissection techniques, but also a clear definition of a muscle is required in order to be able to compare studies and draw clear conclusions. Au cours des dernières années, la définition du quadriceps fémoral (QF) a quelque peu évolué et certains auteurs définissent maintenant une cinquième chef : le tenseur du vaste intermédiaire (TVI). Les descriptions des différents composants QF dans les manuels d’Anatomie et les résultats récemment publiés sont contradictoires. L’objectif de cette étude est donc d’obtenir plus d’informations sur ce potentiel chef supplémentaire. Vingt membres inférieurs de 10 cadavres embaumés, six femmes et quatre hommes, ont été examinés par macro-dissection. La dissection et la séparation des différents chefs ont été effectuées avec les doigts et une distinction entre les différentes parties du quadriceps n’a été notée que s’il était possible de séparer les têtes sans scalpel pour éviter une séparation artificielle des parties musculaires. Dans 9 membres inférieurs, nous avons trouvé un