Background: Studies of acetabular reconstruction with use of cement
and bulk bone graft have demonstrated increasing rates of cup failure in
patients with dysplastic hips seven years after total hip arthroplasty.
Comparable data on the long-term results of bulk bone-grafting done in
conjunction with cementless implants are limited. The aim of this study was to
review the clinical and radiographic results of autologous bulk bone-grafting
in conjunction with a cementless cup.
Methods: From 1987 to 1992, forty-seven patients (forty women and
seven men, with an average age of 50.4 years) who had developmental dysplasia
of the hip underwent fifty-six total hip arthroplasties and received a
structural graft in combination with a cementless Harris-Galante type-I cup.
All patients were followed prospectively. In fifty-five hips, implant
migration was measured with single-image radiographic analysis.
Results: After an average duration (and standard deviation) of 10.2
± 2.9 years, three patients (four hips) had died. In the surviving
patients, four implants had been revised and two had radiographic evidence of
loosening. With use of revision and loosening as end points, the eleven-year
survival rates were 91.6% and 88.9%, respectively. Of the fifty implants that
had no loosening, fourteen had measurable cup migration, thirty-five had no
migration, and one implant could not be measured. All migrations but one were
progressive. With loosening used as the end point, the survival rate at eleven
years was 100% for the implants with no migration; however, the survival rate
for the cups that had migrated was 69.3% (p = 0.0012).
Conclusions: The eleven-year survival rate for the spherical
press-fit cups in combination with bulk bone-grafting is satisfactory, given
the complexity of these reconstructions. However, the difference between the
survival of the implants that had migrated and those that had not was
significant. We expect that the thirteen implants with progressive acetabular
migration at the time of the latest follow-up are at risk for loosening, which
will increase the revision rate for this series in the coming years.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.