Table 2.

Outcome of the Oxford unicompartmental knee arthroplasty, by country

	Follow-up period	Revisions/ primaries (%)	No. of primary cases	No. of revision cases	Observed component years	Revisions per 100 observed component years	CI	Factor difference to the average
Australian Registry	3.55	6.88	8,644	595	30,720	1.9	1.8–2.1	0.97
Finnish Registry	2.72	6.23	2,361	147	6,417	2.3	2.0–2.7	1.2
Swedish Registry	5	8.5	980	83	4,900	1.7	1.4–2.1	0.86
Total/Average	3.51	6.88	11,985	825	42,037	2.0	1.8–2.1

Sources: Australia: Annual Report 2008; Finland: Yearbook 2006; Sweden: Annual Report 2007.