A bifurcated plantaris muscle: another confirmation of its high morphological variability? Another type of plantaris muscle

Abstract

The plantaris muscle usually begins with a short, narrow belly in the popliteal fossa at the lateral supracondylar line of the femur and the knee joint capsule. Then it form a long and slender tendon and usually inserts into the calcaneal tuberosity on the medial side of Achilles tendon. Nevertheless, many anatomical variations of distal attachment have been described. Cases of atypical proximal origin are reported less frequently. In this paper, we have presented a case of a two headed plantaris muscle. First head attached to the condyle of the femoral bone, medially and inferiorly to the lateral head of the gastrocnemius muscle. The second one originated from the popliteal surface of the femur, just above the intercondylar fossa. According to present literature, no such case with atypical proximal origin was presented such information has potentially clinical significance during the surgical procedures performed in the area of the popliteal fossa.

A three-headed plantaris muscle with a bipartite insertion of its two accessory heads

“…Olewnik et al [10] identi ed a "double PM" and a "bifurcated PM" in 0.8% of their sample, per each form. During a forensic autopsy, Smedra et al [14] observed a PM with two muscular heads that fused to a common tendon, which corresponds to Olewnik et al [10] "bifurcated PM". Futa et al [3] observed another morphological variant similar to Smedra et al [14].…”

“…During a forensic autopsy, Smedra et al [14] observed a PM with two muscular heads that fused to a common tendon, which corresponds to Olewnik et al [10] "bifurcated PM". Futa et al [3] observed another morphological variant similar to Smedra et al [14]. Contrariwise, Kurtys, and coauthors [8] and Heo et al…”

Accessory plantaris muscle can result in symptomatic hardware impingement following ACL reconstruction

“…There have been numerous reports detailing the anatomic variations of the plantaris muscle, including differences in its origin and insertion points [ [5] , [6] , [7] , [9] , [10] , [11] ]. However, the identification of an accessory plantaris with a separate muscle belly is a rare occurrence [ 5 , 9 , 12 , 13 ]. In a study that used MRI, Herzog et al.…”

“…In a study that used MRI, Herzog et al. found that an accessory plantaris was present in 6.3% of their study population [ 9 , [12] , [13] , [14] ]. Other instances of accessory plantaris have been identified in cadaveric studies, and there have been discussions regarding the potential implications of such variations for surgical procedures involving the popliteal fossa [ 9 , [12] , [13] , [14] ].…”

“…found that an accessory plantaris was present in 6.3% of their study population [ 9 , [12] , [13] , [14] ]. Other instances of accessory plantaris have been identified in cadaveric studies, and there have been discussions regarding the potential implications of such variations for surgical procedures involving the popliteal fossa [ 9 , [12] , [13] , [14] ]. While there have been reports of surgical implications associated with plantaris origin variants, there are no published cases thus far of an accessory plantaris negatively impacting surgical outcomes, as in the case of the ACL reconstruction described in this study.…”