Possible effect of morphological variations of plantaris muscle tendon on harvesting at reconstruction surgery-case report

Abstract

Purpose Seemingly a well-known, weak, and vestigial plantaris muscle should not be a revelation. However, recent studies have shown that this structure is incredibly underestimated and perceived only as an infirm flexor of the talocrural joint, the knee joint or a great source of graft tissue. Usually, the origin of this inconspicuous muscle begins at the lateral supracondylar line of the femur and the knee joint capsule. It continues distally, forming a long and slender tendon. In most cases, it inserts onto the calcaneal tuberosity on the medial side of the Achilles tendon. However, many morphological variations have been discovered during anatomical dissections and surgical procedures. Nevertheless, according to the present literature, no other studies presented such a complex insertion variant, with indisputable clinical value and significant proof of development of this forgotten muscle. Methods The dissection of the right thigh, knee, crural and talocrural region was performed using standard techniques according to a strictly specified protocol. Results Four different insertion points were observed. The first band (A) inserted near to the tarsal canal flexor retinaculum. The second band (B) bifurcates into two branches-B1 and B2. B1 is located on the medial side and B2 is located on the lateral side of the calcaneal tuberosity. The third band (C) is inserted into the superior nonarticular calcaneal surface of the calcaneus anteriorly to the Achilles tendon. Conclusion A differently shaped plantaris tendon could be considered a cause of harvesting procedure failure. In the light of new case reports perhaps what we are now witnessing is remodeling and transformation of the Plantaris muscle. If so, the awareness of the influence on the onset of Achilles midportion tendinopathy or a potential role in tibialis posterior conflict can be crucial for every clinician.

Potential compression of the musculocutaneous, median and ulnar nerves by a very rare variant of the coracobrachialis longus muscle

“… An analysis of digital photographic images was processed using MultiScanBase 18.03 (Computer Scanning System II, Warsaw, Poland). The value and precision of this method have been confirmed in previous studies [20,29,40,42].…”

A three-headed plantaris muscle: evidence that the plantaris is not a vestigial muscle?

“…From this origin, the short muscle belly develops into a long, thin tendon, which usually runs in the "space" between the GM and the SM, inserting on to the medial calcaneus and adjacent fibrous tissues [7,11,22,23,31]. Morphological variations have been described more often in the distal attachment than the proximal attachment; however, both are characterized by frequent variation [7,9,11,13,17,22,23,25].…”

“…Morphological variations have been described more often in the distal attachment than the proximal attachment; however, both are characterized by frequent variation [ 7 , 9 , 11 , 13 , 17 , 22 , 23 , 25 ].…”

Is the plantaris muscle the most undefined human skeletal muscle?

“…Following the morphological examination of this unusual plantaris muscle, measurements were made. These were taken as digital photographic images and processed through Mul-tiScanBase 18.03 (Computer Scanning System II, Warsaw, Poland) (Gonera et al 2020;Kurtys et al 2020). All of them are presented in Table 1.…”

“…The PM shows considerable morphological variability in both its proximal and distal attachments and even its course (Olewnik et al 2017b , 2020a ). Besides the classified variations named types , there are also some very rare cases (Gonera et al 2020 ; Kurtys et al 2020 ). Because of their rarity, they could seem insignificant, but clinical science shows that even uncommon variants are sometimes crucial for correct differentiation and diagnosis and, therefore, for the health of patients (Rohilla et al 2013 ).…”