Objective: To identify the location of the vastus intermedius nerve and its
motor point (point M) and to precisely identify its coordinates in relatio
n to anatomic surface landmarks.
Design: Descriptive study.
Setting: Anatomy institute of a university school of medicine.
Participants: Twenty-nine adult cadaver Limbs immobilized in anatomic posit
ion.
Intervention: Anatomic dissection to identify point M, Anatomic surface lan
dmarks were point F, the issuing point of femoral nerve under the inguinal
ligament; point R, the middle of superior edge of the patella; segment FR,
which corresponds to thigh length; point M', point M orthogonal projection
on segment FR,
Mean Outcome Measure: Absolute vertical coordinate, distance FM, relative v
ertical coordinate compared to the thigh length, FM'/FR ratio; absolute hor
izontal coordinate, distance MM',
Results: The absolute vertical coordinate was 11.7 +/- 2cm. The relative ve
rtical coordinate was at .29 +/- .04 of thigh length. The horizontal coordi
nate was at 2 +/- .5cm lateral to the FR line.
Conclusion: Point M can be defined with relative precision by two coordinat
es. Application and clinical interest of nerve blocking using these coordin
ates in quadriceps spasticity should be studied.