Abstract
Satisfactory results have been achieved with unicompartmental knee arthroplasty (UKA)
for the treatment of isolated unicompartmental knee disease. However, UKA is associated
with a significantly higher rate of revision. There is a tendency toward early revision
of UKA for persistent pain because surgeons are not aware that outcomes can spontaneously
improve with time. The aim of this study was to identify the time period that patients
achieved the highest clinical outcomes following UKA. In total, we examined 72 knees
that underwent Oxford UKA. We evaluated the range of motion and clinical results including
Knee Society Knee Score, Knee Society Function Score (KSFS), and patient-reported
scores using the Knee injury and Osteoarthritis Outcome Score (KOOS) at 1, 2, and
3 years postoperatively. The extension angle showed significant recovery from 1 to
2 years postoperatively, but no significant recovery was observed between 2 and 3
years. The flexion angle at 2 years is larger than at 1 year. The KSFS at 3 years
is significantly lower than that at 1 year. The KOOS subscale of activities of daily
living showed no significant differences among three periods after operation. The
subscales of pain, symptom, sports, and quality of life showed significant recovery
from 1 to 2 years postoperatively, but no significant recovery was observed from 2
to 3 years. To evaluate the effectiveness of Oxford UKA, surgeons should obtain clinical
outcomes 2 years after the operation.
Keywords
unicompartmental knee arthroplasty - Oxford knee system - patient-reported outcome
- unnecessary earlier revision - deterioration with age
