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

Abstract

Introduction: 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.Materials and methods: 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.Results: 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.Conclusion: 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. KeywordsQuadriceps femoris; extensor apparatus of the knee joint; tensor vastus intermedius

Quadriceps or multiceps femoris?—Cadaveric study

“…Veeramani et al confirmed this classification in their study of 36 limbs of the South Indian population (Veeramani & Gnanasekaran, 2017); however, the tendons did not show as much diversity. In contrast, Bonnechère et al (2020)'s study identified the TVI in only seven of 20 limbs studied, and in four cases, it was not possible to differentiate the VI and VM or the VI and VL.…”

“…The fifth head's incidence has been found to range from 29 to 100% (Bonnechère et al, 2020; Grob, Ackland, et al, 2016; Veeramani & Gnanasekaran, 2017; Willan et al, 1990). Golland and Mahon (1986) reported the presence of a separate muscle belly of the VL in 29% of dissected limbs, while Willian et al (1990) observed an additional muscle between the VL and VI in 36% of cases, and Bonnechère et al (2020) noted the TVI's presence in 35% of limbs. In contrast, both Grob, Ackland, et al (2016) and Veeramani and Gnanasekaran (2017)) reported that the TVI was present in all limbs examined.…”

“…A larger sample size would have been desirable; however, the small size (n = 106) was attributable to the muscle's morphological variability. Nonetheless, the study had a large sample size compared to previous studies (Bonnechère et al, 2020;Veeramani & Gnanasekaran, 2017) and shows significant differences. In addition, the study population was recruited from a specific population of people who have lived the better part of their lives in the region around Lodz, Poland.…”

“…Currently, it is uncertain whether the QF can be regarded as a quadriceps muscle. Although the previous literature has only reported the possibility of the duplication of the VL or VM (Le Double, 1897; MacAlister, 1875), recent studies have indicated the possibility that there may be a fifth head of the QF: the tensor of the vastus intermedius (TVI) (Bonnechère, Louryan, & Feipel, 2020; Golland & Mahon, 1986; Grob et al, 2015; Grob, Ackland, Kuster, Manestar, & Filgueira, 2016; Grob, Manestar, et al, 2016; Veeramani & Gnanasekaran, 2017; Willan, Mahon, & Golland, 1990).…”

Tensor vastus intermedius: a review of its discovery, morphology and clinical importance

“…Interestingly however, a recent study investigating the tensor vastus intermedius found conflicting results when compared to the above. The study demonstrated the muscle in only seven of the twenty lower limbs studied [3], and the authors called into question the definition of this muscle. Perhaps, therefore, clarity is needed regarding the muscle's definition in order to allow for objective and comparable research to be undertaken.…”