Pitfall: too long a guide wire
It is important to remember that the distal femur tapers from the posterior
to the anterior. Therefore, if a straight AP view is obtained, the guide wire
can appear to be inside the bone. If it appears to be outside the bone, it is
most likely too long and the DCS will cause pain and possibly heterotopic
ossification. In order to assess the exact length of the guide wire obtain an
AP view with 30° internal rotation of the lower extremity.