Background: Classification of fractures of the greater tuberosity
has shown poor reliability, in part as a result of an inability to assess
fracture displacement accurately. We used fluoroscopic images of prepositioned
osteotomized greater tuberosity fragments in cadavers to determine the
accuracy of radiographic interpretation, the interobserver reliability, and
the effect that radiographs might have on surgical decision-making.
Methods: Twelve osteotomies of the greater tuberosity (three each
with 2, 5, 10, and 15 mm of displacement) were created in whole-body cadavers.
Six fluoroscopic images (anteroposterior views in external and internal
rotation, anteroposterior views in neutral rotation with 15° of cephalic
and 15° of caudal tilt, a lateral outlet view, and an axillary view) were
made after each osteotomy. Four experienced orthopaedic surgeons measured
displacement in millimeters on seventy-two randomized images. Four views in
sequence (the anteroposterior view in internal rotation and the outlet view
together, then the axillary view, and then the anteroposterior view in
external rotation) of each osteotomy pattern were then viewed, and each
surgeon was asked whether surgery would be indicated on the basis of each set
Results: No one fluoroscopic view was significantly more accurate
than another. There was a trend toward increased accuracy of imaging of
minimally displaced (=5 mm) tuberosity fragments with the anteroposterior
view in external rotation. When viewed sequentially, the anteroposterior view
in external rotation, evaluated last, altered treatment in nine of forty-eight
situations. There was substantial agreement (? = 0.71) among the
surgeons with respect to their recommendations for treatment of the displaced
greater tuberosities after they had inspected the four images.
Conclusions and Clinical Relevance: To our knowledge, we are the
first to examine the accuracy and reliability of interpreting images of known
displacements of the greater tuberosity. Multiple radiographic views are
needed to evaluate displacement of the greater tuberosity appropriately. The
anteroposterior view in external rotation can profile the greater tuberosity
and help demonstrate small displacements. Treatment decisions should be
consistent between surgeons when multiple views are used.