The vastus intermedius is the deepest quadriceps component, lying directly on the anterior femur. It is the component responsible for the articularis genu (an extension of its deepest fibres) which prevents the suprapatellar bursa from being caught in the joint during extension.
| Origin | Anterior and lateral surfaces of the femoral shaft — upper two-thirds |
|---|---|
| Insertion | Quadriceps tendon — deep surface, blending with the other vasti |
| Nerve Supply | Femoral nerve branches (L2, L3, L4) |
| Blood Supply | Lateral circumflex femoral artery — descending branch |
| Actions | Extends the knee — the deep quadriceps component; Stabilises the knee against varus and valgus forces through its broad femoral attachment |
|---|
Vastus intermedius is the layer elevated from the femur in anterior quadricepsplasty for post-traumatic knee stiffness. Myositis ossificans in the vastus intermedius after femoral contusion produces a palpable mass and knee flexion limitation.
Not individually palpable from the overlying rectus femoris.
Post-traumatic heterotopic ossification within the vastus intermedius after femoral contusion producing a hard intramuscular mass and progressive knee flexion restriction.
