ABSTRACT
The aim of the study was to assess population variation of the vastus medialis obliquus (VMO) insertion to the patella. Sixty-five magnetic resonance imaging studies and 18 cadaver specimens were studied. The VMO insertion was expressed as a percentage of patellar length. In the magnetic resonance imaging cohort, the mean insertion was 51% (range 13-95); 59% (38 of 65) of individuals had an insertion within 40% to 60%, with 25% (16 of 65) being distal to 60%. In the cadaveric study, mean insertion was 52% (range 26-81). Both groups displayed a Gaussian distribution. Laterality and sex had no effect upon the level of insertion. The VMO has a variable and frequently distal insertion that may preclude a true quadriceps-sparing approach during minimally invasive knee arthroplasty.
