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.