MHRA Device Safety Information (DSI) notice - Cobalt-chrome modular neck hip replacements: risk of metal wear effects and revision surgery (DSI/2026/010)

An investigation by the Medicines and Healthcare products Regulatory Agency (MHRA) in 2025 (detailed in DSI/2025/005) found increased risks of wear and corrosion associated with the Profemur cobalt-chrome modular neck hip system, including an increased occurrence of device fracture and revision surgery. A further investigation by the MHRA has examined all other hip replacements with a cobalt-chrome modular neck that have ever been available on the UK market. These devices were all removed from the market prior to 2019 and none remain commercially available.

The MHRA recommends that patients implanted with affected devices should be invited for a virtual or face-to-face clinical review to inform them of the potential risks, assess their clinical presentation and discuss the need for continued follow-up. Detailed advice for healthcare professionals can be found here.

(Note: Two of the systems in scope of this DSI (ABG II modular and SMF) have already been the subject of previous investigations by the manufacturers. Patients implanted with these devices may not need further follow-up if they are already undergoing monitoring based on the manufacturers’ previous recommendations.)

Background

Cobalt-chrome dual taper modular neck hip replacements were introduced to the market with the intention of allowing better alignment of hip stems to the anatomy of the patient and restoring more natural biomechanics compared to non-modular systems, due to the option for intraoperative decision making. As part of the investigation the potential benefits of this design have been considered alongside the potential increased risk of wear and corrosion associated with the presence of two interfaces: one between the modular neck and the modular hip stem, and another between the modular neck and modular head. The individual benefits and risks of each device have also been considered, given the differences in device design, indications, stated benefits, population of use, number of implants used and available data. The investigation found that the rate of revision due to metal-related effects (such as ALTR) varied between different implant systems. 

Usage and outcomes for these devices is based on data from the UK National Joint Registry (NJR) extracted in June 2026.