Table 1.

Revisions due to implant fractures in datasets of National Arthroplasty Registers

Register	Data source	Data collection	Follow-up (years)	N Primary THA	N Revisions	N Implant fractures	% Implant fractures at all revisions	% Implant fractures of all primary THA	Failure rate per 100,000 observed component years	Factor difference to mean
Swedish Hip Arthroplasty Register	Annual Report 2006	1979–2006	27	296,015	25,984	407	1.57	0.14	10	0.38
New Zealand Orthopaedic Ass. - National Joint Registry	Eight-year Report	1999–2006	7	42,092	1,034	8	0.77	0.02	5	0.20
Australian Orthopaedic Association - National Joint Registry	Annual Report 2007	1999–2006	7	160,349	23,261	700	3.00	0.44	12.5	4.66
Finnish Arthroplasty Register	The 2006 Implant Yearbook on Orthopaedic Endoprostheses	1997–2006	10	65,062	13,113	262	2.00	0.40	8.1	3.01
Danish Hip Arthroplasty Register	Annual Report 2006	1995–2005	11	75,304	10,381	512	4.93	0.68	12.4	4.62
National Joint Registry for England and Wales	4th Annual Report	2006	1	55,052	5,296	201	3.80	0.37
Canadian Joint Replacement Registry (CJRR)	Annual Report 2007	2003–2006	4	39,162	3,464	137	4.00	0.35
Total/average			7.57	733,036	82,533	2,227	2.70	0.30	27