Unicondylar knee replacement for primary osteoarthritis: A prospective follow-up study of 1,819 patients from the Finnish Arthroplasty Register

Abstract

Background The choice and use of unicondylar knee arthroplasty (UKA) has gone through a nation wide resurgence at the start of the 21st century in Finland. We evaluated the population-based survival of UKA in patients with primary osteoarthritis (OA) in Finland, and the factors affecting their survival.Method The Finnish Arthroplasty Register was established in 1980. During the years 1985-2003, 1,928 primary UKAs were recorded in the register; 1,819 of these were performed for primary OA. Of these 1,819 UKAs, we selected for further analysis implants that had been used in more than 100 operations during the study period. The survival rates of UKAs were analyzed using Kaplan-Meier analysis and the Cox regression model.Results Analysis of the whole study period showed that UKAs had a 73% (95% CI: 70-76) survival rate at 10 years, with revision for any reason as the end point. Those patients who received the Oxford menisceal bearing unicondylar (n = 1145) had a survival rate of 81% (95% CI: 72-89) at 10 years. The group that received the Miller-Galante II unicondylar (n = 330) had a 79% survival rate (95% CI: 71-87) at 10 years, whereas the Duracon (n = 196) had a survival rate of 78% (95% CI: 72-84) and the PCA (n = 146) had a survival rate of 53% (95% CI: 45-60) at 10 years. The number of UKA operations in Finland has increased markedly in recent years. At the time of operation, the mean age of the patients was 65 (38-91) years. Younger patients (≤ 65 years of age) were found to have a 1.5-fold (95% CI:

Registry Outcomes of Unicompartmental Knee Arthroplasty Revisions

“…In our registry, the CRR is higher for primary UKA compared with TKA, indicating a decreased overall survivorship for UKA compared with TKA, a finding consistent with those reported previously [8,9,15,17,20]. In contrast, no difference was found in the secondary CRR between the rev-UKA and rev-TKA groups.…”

“…Some reports have cited reliable UKA survivorship of greater than 90% for more than 10 years after implantation [1,11,19,21,26]. When compared with TKA as an index arthroplasty procedure, however, the cumulative revision rate for UKA tends to be higher [8,9,15,17,20].…”

Long-term clinical results of the Oxford medial unicompartmental knee arthroplasty

“…Our survivorship at five years is included in the result range: 85% [2] to 97.7% [15]. Unfortunately, at ten years our results are inferior to those of other studies: 81% [9] to 97.7% [15]. Our relatively poor results are explained by inappropriate patient selection in three cases (one inflammatory arthropathy and two ACLdeficient knees).…”

Incidence of osteotomies around the knee for the treatment of knee osteoarthritis: A 22-year population-based study

“…Over the past decade, the incidence of osteotomies has decreased because of the clinical success of total knee arthroplasty (TKA) [1]. Furthermore, at the same time, the number of unicondylar knee arthroplasties (UKA) has grown [2], which may also have contributed to the decreased number of osteotomies performed. However, symptomatic and radiographically mild to moderate knee OA in young and active patients is still commonly regarded as an indication for high tibial osteotomy [3][4][5].…”