Quantitative ROI differences for assessment of occult intertrochanteric extension of greater trochanteric fractures on pelvis CT.

Purpose: To determine if difference in Hounsfield Units (HU) of the medullary bone between the injured and non-injured femurs in patients with greater trochanteric fractures is associated with occult intertrochanteric (IT) extension.

Methods: Retrospective review was performed of 81 patients (age range 54-102, 54 females and 27 males) who underwent CT and subsequent MRI after identification of a greater trochanteric fracture without evidence of IT extension on radiography and/or CT. Hounsfield units of the injured and non-injured femurs on CT were recorded at the level of the base of the greater trochanter centrally (ROI1) and the level of the upper border of the lesser trochanter posteromedially (ROI2).