NJR Implant Scrutiny Committee (ISC)

The ISC comprises its Chair, Vice Chair, the NJR Medical Director, surgeon members from the RCCs committee, a patient representative, representatives from the NJR’s core contractors: University of Bristol (our Lot 2 providers), NEC Software Solutions (our Lot 1 providers), representatives of the Medicines and Healthcare products Regulatory Agency (MHRA), representatives from the NJR Management Team and from the Orthopaedic Data Evaluation Panel (ODEP)/Beyond Compliance.

Examining the data

The registry data is refreshed and analysed every six months. The committee assesses potential outlier implant performance and notifies the MHRA when there are concerns. In addition, the committee also responds to any queries and concerns raised by surgeons and regulators, undertaking additional analysis to investigate and report on these where necessary.

To date, the Patient Time Incidence Rate (PTIR) method has been used by the NJR to identify poor performance, (in line with other registries) however it became apparent that this method alone was not sensitive enough to identify failure in sub-groups or in the longer-term, and in some cases missing out on relatively early poor performance. Over the past few years, a new statistical methodology had been developed using Kaplan-Meier estimates alongside the existing method. The aim is for the NJR to move to this methodology entirely by the end of 2025/26 financial year. An updated NJR Accountability and Transparency model for implant outlier monitoring will be published to reflect these changes, and associated engagement on this will take place with industry and key stakeholders.

A review of implant branding across the NJR continues, to ensure consistency across manufacturers and to also enable a more consistent stratification of implants as part of outlier analysis.

Future developments

A working group is currently developing the processes and methodology to enable us to monitor the performance of shoulder implants more closely, in line with the current processes for hip and knee implants. This key development will ensure the NJR’s commitment to deeper levels of scrutiny in relation to implant performance.

The committee will continue to work closely with EPRD (the German registry) and ISAR (International Society of Arthroplasty Registries) on the development of an international shoulder component classification, having now agreed on adopting a comprehensive classification for hips and knees.

Implants and combinations identified as outliers

Details of implants and combinations identified as Level 1 outliers are again included in this year’s report. We encourage all surgeons to review this carefully to help inform their clinical decisions. Since the 2024 report, there has been five notifications to the MHRA for hip implants (CLS Spotorno Cementless Stem, X3 Rimfit Cemented Cup, Delta Revision TT, Delta Multihole TT, and the Birmingham Head Resection Stem used with the BHR Resurfacing Cup) and two for knee implants (Legion Revision Oxinium PS and Maxim Unconstrained). Details can be found here.