<prompt> Avascular necrosis of head of femur occurs commonly at :Subcapital regionTranscervical regionSubchondral regionTrochanteric region  <response>: Avascular necrosis is common with fractures to the subcapital region. Subcapital fractures damage the ascending vessels, thereby causing avascular necrosis and nonunion. Subcapital is the most common location for a femoral fracture. Ref: Srinivasan R.C., Tolhurst S., Vanderhave K.L. 2010. Chapter 40. Ohopedic Surgery. In G.M. Dohey Ed, CURRENT Diagnosis Treatment: Surgery, 13e. 