Popliteus muscle. An anatomical study

Background: The popliteus muscle fulfills a function of rotational stabilizer of the knee. Its particular shape and innervation pattern are the interest of anatomists and surgeons. The aim of this work was characterizing the anatomy and innervation of the popliteus muscle of knees from a sample of mestizo-raced population, predominant in Latin America.   Methods: This cross-sectional study was made in 23 knee segments 14 right knees and 9 left knees coming from 14 men and 9 women aged 67 ± 22 years.   Results: The popliteus muscle presented a scalene-like triangle shape and its medial base was covered by the superficial expansion of the semimembranosus tendon. The length of its base was 79,2±12,8 mm with a superior and inferior side that measured 58.0±7.4 mm and 101.7±11.7 mm respectively. The popliteus muscle innervation was supplied by the tibial nerve (TN) by the arising of two branches in 22 cases (95.7%). The first branch arose proximal to the inter articular line and presented a length of 91,1 mm. The second branch arose distally to the inter articular line with a length of 48.4±1.3mm. The third was observed in just one case (4.3%) Its length was 108±1.1mm and it arose distally to the inter articular line.   Conclusions: The morphological characteristics of the popliteus muscle and its innervation patterns found in our study differ from what was reported in previous studies. The presence of these findings can be considered during the planning of surgical procedures in the posterior aspect of the knee.