Background: This follow-up study updates the
results in a consecutive series of nineteen cemented total hip replacements
with a swan-neck femoral component in patients with congenital dislocation
or severe hip dysplasia. The series was previously reported on in
Methods: The patients were petite, with an average
height of 152 cm and an average weight of 50 kg, and the femoral
canals could not accommodate an off-the-shelf femoral component.
Sixteen of the nineteen hips were available for follow-up at an average
of 13.3 years (range, eleven to twenty years). Fourteen hips had
up-to-date clinical and radiographic examinations.
Results: At the time of the latest follow-up, thirteen
hips were rated as excellent; two, as good; and one, as a failure
because of loosening of both components requiring revision eleven
years after the index operation. Another hip required acetabular revision
because of loosening fifteen years after the index operation. The
rates of femoral and acetabular component revision were 6% and
12.5%, respectively. Radiographic analysis demonstrated
that no femoral component was loose. One cup was definitely loose
at 19.5 years, and three cups were possibly loose at an average
of fourteen years. The radiographic rate of acetabular loosening
was 33%. The total rate of cup failure (radiographic loosening
and revision) was 43%.
Conclusions: The excellent clinical and radiographic
results associated with the swan-neck femoral component, and the
94% rate of survival, at an average of 13.3 years (range,
eleven to twenty years) indicate that the biomechanical objectives
of this custom-designed prosthesis for patients with congenital
dislocation or severe hip dysplasia were met. On the basis of this favorable
long-term experience, we still use this prosthesis when the anatomic
abnormality cannot be adequately addressed by use of a commercially
available prosthetic component.