Background: An ipsilateral fracture of the femoral neck is seen in
association with 1% to 9% of femoral shaft fractures, and 20% to 50% of these
injuries are missed initially. Recognition of an associated femoral neck
fracture prior to stabilization of the femoral shaft fracture is imperative to
avoid or minimize complications of displacement and osteonecrosis.
Methods: A protocol to look for a femoral neck fracture in all
patients with a femoral shaft fracture was instituted at a single level-I
trauma center. This protocol consisted of a dedicated anteroposterior internal
rotation plain radiograph, a fine (2-mm) cut computed tomographic scan through
the femoral neck, and an intraoperative fluoroscopic lateral radiograph prior
to fixation as well as postoperative anteroposterior and lateral radiographs
of the hip in the operating room prior to awakening the patient. A chi-square
analysis comparing pre-protocol and post-protocol fracture prevalences was
used to assess the relative risk of missing an associated femoral neck
fracture.
Results: Two hundred and sixty-eight consecutive patients with a
femoral shaft fracture formed the basis of the study group. Of 254 who were
followed for at least two months, sixteen were identified as having an
associated ipsilateral femoral neck fracture with use of the protocol.
Thirteen associated femoral neck fractures were identified before the patient
entered the operating room for definitive fixation, and twelve of them were
identified with the fine-cut computed tomographic scan. One fracture was
identified intraoperatively. There was one iatrogenic fracture and one delayed
diagnosis of a femoral neck fracture. With this protocol, we reduced the delay
in diagnosis by 91% as compared with our experience in the year prior to the
initiation of the protocol.
Conclusions: In the presence of a femoral shaft fracture, evaluation
of the femoral neck with fine-cut computed tomography and dedicated internal
rotation hip radiographs significantly improves the ability to diagnose an
associated femoral neck fracture.
Level of Evidence: Diagnostic Level II. See Instructions
to Authors for a complete description of levels of evidence.