Background: Fractures occurring at or near the distal tip of a hip
prosthesis with a stable femoral stem (Vancouver type-B fractures) are
associated with many complications because of the inherently unstable fracture
pattern. Locking compression plates use screws that lock into the plate
allowing multiple points of unicortical fixation. Such unicortical fixation
may lower the risk of damage to the cement mantle or a stable femoral stem
during the treatment of a periprosthetic femoral fracture. The purpose of this
study was to analyze clinically and radiographically a group of patients with
a Vancouver type-B1 periprosthetic femoral fracture treated with open
reduction and internal fixation with use of a locking compression plate.
Methods: Fourteen consecutive patients (fourteen hips) with a
Vancouver type-B1 periprosthetic femoral fracture were treated with a locking
compression plate. There were five men and nine women with an average age of
sixty-eight years at the time of fracture. All of the fractures occurred after
a total hip arthroplasty performed with cement, and eleven of the
arthroplasties were revisions. In addition to the plate, cortical strut
allografts were used to stabilize five fractures. The patients were assessed
clinically and radiographically.
Results: The average duration of follow-up was twenty months. Eight
fractures healed uneventfully at an average of 5.4 months. Three treatment
constructs failed with fracture of the plate within twelve months after
surgery. An additional three constructs also failed because of plate pullout.
All failures except one occurred in constructs in which a cortical strut
allograft had not been utilized.
Conclusions: On the basis of the high failure rate in this series of
patients, locking compression plates do not appear to offer advantages over
other types of plates in the treatment of type-B1 periprosthetic femoral
fractures. Despite the potential to preserve the cement mantle, the locked
screws did not appear to offer good pullout resistance in this fracture type.
We believe that supplementation with strut allografts should be used routinely
if this type of locking compression plate is selected to treat these
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.