Distribution of the tensor of the vastus intermedius.

The tensor of the vastus intermedius (TVI) was first described by Grob et al. in 2016. It originates from the anteroinferior greater trochanter and inserts into the upper patella and receives blood and nerves independently of other muscles. It has been overlooked, but since micro-surgery and detailed rehabilitation treatments are being developed, more research on it is warranted. Here we report on the TVI in a Korean cadaveric study. A total of 58 cadavers (41 males and 17 females) were included. Thighs were examined using a standardized dissection protocol. The quadriceps femoris muscle was identified and its components were defined by blunt dissection. A total of 116 lower limbs were dissected. In 40 of them, there was a separately innervated TVI muscle belly between the fasciae of the vastus lateralis (VL) and the vastus intermedius (VI) muscles. TVIs were classed as independent (ID), VI, and VL types according to the relative relationship between the TVI, VL, and VI, and subdivided into two parts: Part 1 was the proximal muscular portion of the TVI attached to the VL or VI, and part 2 was the distal aponeurotic area. TVIs were analyzed in detail via 58 Korean cadavers. We subdivided them on the basis of their location and association with related muscles. A larger study is needed to clarify the function and prevalence of the TVI.