Background: Total hip resurfacing has become increasingly popular
over the last decade. There remains concern about the effect of the surgical
approach on femoral head viability and the role of resurfacing in the
management of established osteonecrosis. In view of these concerns, we
examined femoral head viability following resurfacing through a modified
Methods: The viability of the femoral heads of ten patients who had
undergone successful unilateral Birmingham hip resurfacing was assessed with
use of positron emission tomography in conjunction with the injection of
fluorine at a mean of twenty months after surgery. For each patient, in both
the hip that had undergone resurfacing and the contralateral nonresurfaced
hip, activity was measured in four regions of interest: the lateral aspect of
the femoral head, the medial aspect of the femoral head, the lateral aspect of
the femoral neck, and the proximal aspect of the femur. The uptake of fluorine
in each area was converted to standard uptake volumes.
Results: No areas of osteonecrosis were seen in the femoral head of
any patient. There were no significant differences in the standard uptake
volumes as measured in the four regions of the nonresurfaced hips, whereas the
median values were higher in all four regions of the resurfaced hips. The
difference between the values in the resurfaced hips compared with those in
the nonresurfaced hips was only significant (p < 0.05) in the lateral
aspect of the femoral head.
Conclusions: This study establishes positron emission tomography in
conjunction with injection of fluorine as a possible modality for the
assessment of femoral head viability after hip resurfacing. Viability
following successful Birmingham hip resurfacing performed through a modified
anterolateral approach has also been demonstrated. The increase in bone
activity that was seen in the resurfaced hips in our study group may be
related to bone remodeling or reperfusion of small areas of osteonecrosis.
This technique offers the potential to study femoral head perfusion and
viability following all types of resurfacing.
Level of Evidence: Diagnostic Level IV. See Instructions
to Authors on
jbjs.org for a
complete description of levels of evidence.