Abstract
Background
Unicompartmental knee replacements (UKR) converted to total knee replacements (TKR) have often been viewed with scepticism because of the perceived difficulty of the revision and because revision procedures generally do less well than primaries.
Methods
This is a prospective review of TKRs converted from a UKR between 1982 and 2000. We present the survivorship of a 77 patient cohort and the clinical results of 35 patients. All information was recorded at the time of surgery onto a database and patients have been regularly reviewed since.
Results
The 77 patients in the survivorship study had an average follow-up of 6.9 years and an average Bristol Knee Score of 78.5. Using Kaplan-Meier survivorship analysis a 91% survivorship at 10 years was demonstrated.
Only 35 patients are currently alive and available for examination. The average age at which the UKR was performed was 59.8 yrs, with a time to failure averaging 8.2 yrs. The average age at revision to TKR was 66.1 yrs. There was an average follow-up period of 10.5 yrs and an average Bristol Knee Score of 78.2 with 16 excellent, 11 good, 5 fair and 3 failed results.
Conclusion
Previous studies have shown that revision of UKR to TKR is not technically difficult. This study shows that the survivorship following revision of a UKR is comparable to that of a primary TKR but the clinical results are less good.
