Background: There is a renewed interest in unicompartmental knee
arthroplasty. The present report describes the minimum ten-year results
associated with a unicompartmental knee arthroplasty design that is in current
Methods: Sixty-two consecutive unicompartmental knee arthroplasties
that were performed with cemented modular Miller-Galante implants in fifty-one
patients were studied prospectively both clinically and radiographically. All
patients had isolated unicompartmental disease without patellofemoral
symptoms. No patient was lost to follow-up. Thirteen patients (thirteen knees)
died after less than ten years of follow-up, leaving thirty-eight patients
(forty-nine knees) with a minimum of ten years of follow-up. The average
duration of follow-up was twelve years.
Results: The mean Hospital for Special Surgery knee score improved
from 55 points preoperatively to 92 points at the time of the final follow-up.
Thirty-nine knees (80%) had an excellent result, six (12%) had a good result,
and four (8%) had a fair result. At the time of the final follow-up,
thirty-nine knees (80%) had flexion to at least 120°. Two patients (two
knees) with well-fixed components underwent revision to total knee
arthroplasty, at seven and eleven years, because of progression of
patellofemoral arthritis. At the time of the final follow-up, no component was
loose radiographically and there was no evidence of periprosthetic osteolysis.
Radiographic evidence of progressive loss of joint space was observed in the
opposite compartment of nine knees (18%) and in the patellofemoral space of
seven knees (14%). Kaplan-Meier analysis revealed a survival rate of 98.0%
± 2.0% at ten years and of 95.7% ± 4.3% at thirteen years, with
revision or radiographic loosening as the end point. The survival rate was
100% at thirteen years with aseptic loosening as the end point.
Conclusions: After a minimum duration of follow-up of ten years,
this cemented modular unicompartmental knee design was associated with
excellent clinical and radiographic results. Although the ten-year survival
rate was excellent, radiographic signs of progression of osteoarthritis in the
other compartments continued at a slow rate. With appropriate indications and
technique, this unicompartmental knee design can yield excellent results into
the beginning of the second decade of use.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.