Impact of plantaris ligamentous tendon

Abstract

There are countless morphological variations among the muscles, tendons, ligaments, arteries, veins and nerves of the human body, many of which remain undescribed. Anatomical structures are also subject to evolution, many disappearing and others continually emerging. The main goal of this pilot study was to describe a previously undetected anatomical structure, the plantaris ligamentous tendon, and to determine its frequency and histology. Twenty-two lower limbs from 11 adult cadavers (11 left, and 11 right) fixed in 10% formalin were examined. The mean age of the cadavers at death was 60.1 years (range 38–85). The group comprised six women and five men from a Central European population. All anatomical dissections of the leg and foot area accorded with the pre-established protocol. Among the 22 lower limbs, the PLT was present in 16 (72.7%) and absent in six (27.3%). It originated as a strong fan-shaped ligamentous tendon from the superior part of the plantaris muscle, the posterior surface of the femur and the lateral aspect of the knee joint capsule. It inserted to the ilio-tibial band. Histologically, a tendon and ligament were observed extending parallel to each other. A new anatomical structure has been found, for which the name plantaris ligamentous tendon is proposed. It occurs around the popliteal region between the plantaris muscle, the posterior surface of the femur, and the ilio-tibial band.

Classification of the popliteofibular ligament

“…The cause of this variation remains unclear; it is possible that the ontological development of the PFL is similar to that of the plantaris muscle and plantaris ligamentous tendon (a new anatomical structure which histologically has tendinous and ligamentous texture), or that it may disappear like the palmaris longus (Olewnik, Gonera, Kurtys, Haładaj, Tubbs, Paulsen, Ramon Sanudo, & Polguj, 2020; Olewnik, Gonera, Podgórski, Sibiński, & Polguj, 2020; Olewnik, Karauda, et al, 2021; Olewnik, Waśniewska, et al, 2018). From an evolutionary and a biomechanical point of view, it can be assumed that the PFL has only recently developed and helps to secure the posterolateral corner of the knee (Olewnik, Karauda, et al, 2021). It provides very effective stabilization of the popliteus muscle, which has many important functions related to the proper functioning of the knee joint.…”

“…The last decade has seen a large number of publications on the morphological variability of the entire knee joint, as well as on diagnosis and treatment of pathology related to the knee joint (LaPrade, 1997; LaPrade et al, 2003; Laprade et al, 2010; Olewnik, Gonera, et al, 2018; Olewnik, Gonera, Kurtys, et al, 2019; Olewnik, Gonera, Podgórski, et al, 2019; Olewnik, Karauda, et al, 2021). Despite this, the posterolateral corner continues to surprise us with its morphological variability concerning the shape of the ligaments, their type, their proximal and distal attachment, and the relationship to the surrounding anatomical structures (Olewnik, Gonera, et al, 2018; Olewnik, Gonera, Kurtys, et al, 2019; Olewnik, Gonera, Podgórski, et al, 2019; Olewnik, Karauda, et al, 2021). The PFL variations have not been fully described.…”

Six-headed coracobrachialis muscle

“…was subjected to routine anatomical dissection for research and teaching purposes at the Department of Anatomical Dissection and Donation. The right upper limb was subjected to traditional anatomical dissection [17,[26][27][28], and a morphological variation of a number of CBM heads was found -Fig. 1.…”

Unknown variant of the accessory subscapularis muscle?

“…A 73-year-old at death female cadaver was subjected to routine anatomical dissection for research and teaching purposes at the Department of Anatomical Dissection and Donation, Medical University of Lodz, Poland. The right upper limb underwent traditional anatomical dissection and a morphological variant of the ASM was found (Olewnik et al 2021 , 2020 ; Podgórski et al 2019 ; Szewczyk et al 2021 ; Zielinska et al 2021a , c ).…”