The Implant Scrutiny Committee reports Level 1 outlier implants to the MHRA. Since the committee’s formation in 2009 there have been seven hip stems, ten hip acetabular (cup) components and 34 hip stem/cup combinations reported. A total of 12 knee brands have been notified. This year, knee implants with and without patella resurfacing are included in the implant outlier analysis.

An implant is considered to be a Level 1 outlier when its Prosthesis Time Incident Rate (PTIR) is more than twice the PTIR of the group, allowing for confidence intervals. These are shown as the number of revisions per 100 prosthesis-years. As of March 2015, we have started to identify the best performing implants, these would have a PTIR less than half that of their group, allowing for confidence intervals. To date no implants have reached that level.

Components and constructs previously reported to MHRA, but no longer at Level 1, are not listed.

Hip implant performance

Table 4.1 Level 1 outlier stems reported to MHRA. Table 4.2 Level 1 outlier acetabular components reported to MHRA.Table 4.3 Level 1 outlier stem/cup combinations. Best performing hip implants

There are no hip implants or combinations performing statistically less than half their expected PTIR.

Knee implant performance

Table 4.4 Level 1 outlier implants reported to MHRA.

Best performing knee implants

There are no knee implants performing statistically less than half their expected PTIR.