Structural diversity of the vastus intermedius origin revealed by analysis of isolated muscle specimens

Abstract

The quadriceps femoris (QF), a major extensor of the knee joint, plays an important role in human movement. However, descriptions of the three vastus muscles of the QF in anatomy textbooks remain confusing. We analyzed 33 QFs by a novel approach, using isolated muscle specimens to clarify the structures of the vastus lateralis (VL), vastus medialis (VM), and vastus intermedius (VI) origins. The origins of the VL and VM were quite constant in shape and location, but the VI was much more structurally diverse. In typical cases (23 of 33), the origin of the VI attached muscularly to the anterior and lateral surface of the femoral shaft. It adjoined the origin of the VL at the lateral lip (LL) of the linea aspera to form a common origin. In some cases (10 of 33), the muscle belly and origin of the VI were much smaller than those in the typical cases; the origin of the VI attached only to the anterior surface of the femur and did not contact the LL. In addition, the muscle belly of the VI was narrow and almost corresponded to the width of the femoral shaft. The isolated muscle specimen is a useful tool for analyzing individual muscle structures, which can be difficult to observe by routine dissection. Using this method, it became clear that the VI is more structurally diverse in its origin than the VL and VM. Clin.

Anatomy, Morphology and Function of the Tensor of Vastus Intermedius: A Systematic Review

“…The variations of TVI musculature have been categorized in two ways, based on its aponeurosis/tendon course [ 10 , 12 , 16 ] and on its proximal attachment [ 11 ] ( Supplementary Materials ). This phenomenon is not uncommon, as previous investigations have revealed similar structural diversity regarding the origin of VI [ 26 ] as well as the degree of fusion between the VL and VI musculatures [ 27 ]. Furthermore, these morphological variabilities especially in TVI’s aponeurosis can be explained by the differences in the extent and location of the fusion between the aponeuroses of VL and VI with the TVI [ 28 ].…”

Anatomic characterization of the femoral nutrient artery: Application to fracture and surgery of the femur

“…In the femur, the FNFs are limited to the posterior surface on or along the linea aspera, but not the anterior surface. The vastus intermedius broadly attaches to the anterior surface of the femur (Yoshida et al, ). Thus, the parent artery, which potentially gives off the nutrient artery, is distant from the anterior surface, resulting in nonformation of the FNFs on the anterior surface during development.…”

Quadriceps femoris muscle: anatomical variations, population frequencies and clinical implications

“…The most common is found on the anterior and lateral surfaces of the femoral body ("contacting type"), reaching the lateral lip of the linea aspera, where it adjoins the vastus lateralis (69% frequency). The least common originates from the anterior surface of the femoral body, without limiting to the vastus lateralis ("non-contacting type") (31% frequency) (Figure 2) [3].…”

“…The vastus medialis arises from the intertrochanteric line, spiral line, and medial lip from the linea aspera. The origin of the vastus intermedius is the upper 2/3 of the anterior and lateral surface of the femoral body [3].…”