Anatomical investigation of tensor vastus intermedius: A cadaveric study

The major muscle in the anterior compartment of the thigh known as quadriceps femoris is made up of four parts; rectus (straight) femoris and three vasti (vastus lateralis, medialis and intermedius). A recently discovered muscle, making the fifth part, called the Tensor vastus intermedius (TVI) has been found in-between vastus lateralis (VL) and vastus intermedius (VI). The aim of this investigation was to study the presence of the TVI muscle, identify neurovascular supply as well as variations in the nature of the muscle and to ultimately classify them. The cadaveric study was conducted in the Gross laboratories of Yusuf Maitama Sule University, Bayero University and Ahmadu Bello University, all in Nigeria. Thirty lower limbs were examined using standard dissection techniques and the TVI was demonstrated in all of them. We then classified the muscle into four types, I to IV based on their origin, course and insertion. The Type I were the independent type; constituting 12 cases (40%), the VI-type (Type II) 7 cases (23%), the VL-type (Type III) 5 cases (17%) and the common type (Type IV) 6 cases (20%). The TVI was supplied by muscular branches of the femoral nerve and receives vascular supply by branches of lateral circumflex femoral artery and vein.