MHRA: DSI/2026/010 Hip Alert Issued for Co-Cr Modular Neck Stems

• The MHRA has issued DSI/2026/010, alerting to increased risks of wear and corrosion in cobalt-chrome modular neck hip replacements.
• These risks can lead to adverse local tissue reaction (ALTR) and a higher likelihood of revision surgery.
• The problem is attributed to two interfaces on the dual taper modular neck design of these implants.
• All affected devices were removed from the UK market before 2019 and are no longer commercially available.
• Patients with these implants are advised to undergo a clinical review, including whole blood testing for cobalt and chromium.

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.

The Medicines and Healthcare products Regulatory Agency (MHRA) has issued a Device Safety Information (DSI/2026/010) alert concerning cobalt-chrome (Co-Cr) modular neck hip stem components. An investigation conducted by the MHRA revealed heightened risks of wear and corrosion associated with these specific hip replacement devices. This deterioration can lead to serious complications for patients.

Specifically, the MHRA found a potential for increased occurrences of revision surgery, primarily due to adverse local tissue reaction (ALTR). The core issue identified is the presence of two distinct interfaces on the dual taper modular neck design: one located between the modular neck and the modular hip stem, and another between the modular neck and the modular head. These interfaces are believed to contribute significantly to the observed wear and corrosion.

Cobalt-chrome dual taper modular neck hip replacements were initially introduced to the market with the aim of improving patient outcomes. Their design intended to allow for better alignment of hip stems with individual patient anatomy and to restore more natural biomechanics compared to non-modular systems, largely due to the flexibility offered by intraoperative decision-making.

This particular MHRA investigation broadened its scope to examine all other hip replacements featuring a cobalt-chrome modular neck that had ever been available on the UK market. It is important to note that all devices falling under the purview of this alert were removed from the market prior to 2019 and are no longer commercially available. The investigation also determined that the rate of revision surgery attributable to metal-related effects, such as ALTR, varied across different implant systems, with data from the UK National Joint Registry (NJR) extracted in June 2026 providing key insights.

In response to these findings, the MHRA recommends that patients who have been implanted with the affected devices should be invited for a clinical review. This review can be conducted virtually or face-to-face, with the primary goals of informing patients about the potential risks, assessing their current clinical presentation, and discussing the necessity for ongoing follow-up care.

As part of the clinical follow-up, a whole blood test for cobalt and chromium is recommended, to be performed by a laboratory associated with one of the specified schemes. However, it is crucial to understand that there is no universally agreed threshold value for whole blood metal levels that can definitively predict outcomes or mandate revision surgery. Decisions regarding revision are complex and are influenced by a combination of patient-specific factors, blood metal levels, imaging findings, and the specific type and position of the implant. Other individual patient factors may also require consideration when interpreting blood metal level results. Patients with ABG II modular and SMF systems, which were previously subject to manufacturer investigations, may not require further follow-up if they are already undergoing monitoring based on those earlier recommendations.

The current investigation, DSI/2026/010, builds upon a preceding inquiry detailed in DSI/2025/005. That earlier investigation specifically identified increased risks of wear, corrosion, device fracture, and revision surgery associated with the Profemur cobalt-chrome modular neck hip system. The present alert extends these concerns to a wider range of similar devices.

Throughout its assessment, the MHRA carefully weighed the potential benefits of the modular design against the identified increased risks of wear and corrosion linked to the dual interfaces. The investigation also took into account the individual benefits and risks of each specific device, considering variations in device design, stated indications, intended benefits, the population of use, the number of implants utilized, and the available data.

Source: Original reporting via UK Government guidance