Futuristic hip implant fading into a medical chart, symbolizing the evolving approach to monitoring metal-on-metal hip arthroplasties.

Metal Hip Implants: Are Routine Blood Tests a Thing of the Past?

Avery Sinclair in Health & Wellness January 2026 • 4 min read.

"New research suggests that annual blood metal level monitoring may not be necessary for patients with metal-on-metal hip arthroplasties. Find out why."

For many years, metal-on-metal (MoM) hip arthroplasties were seen as a game-changer, offering improved mobility and a better quality of life for those suffering from severe hip joint issues. However, this optimism was tempered by the realization that these implants could release metal ions into the bloodstream and surrounding tissues, leading to concerns about potential adverse effects.

This led to the widespread practice of routinely monitoring blood metal levels in patients with MoM hip implants, with the aim of detecting early signs of implant failure or adverse reactions. But now, a growing body of evidence suggests that this practice may not be as necessary as once thought. A recent study published in the journal Revista Española de Cirugía Ortopédica y Traumatología sheds light on this issue, questioning the value of annual blood metal level monitoring in asymptomatic patients.

This article dives into the findings of this study, exploring the implications for patients and healthcare providers alike. We'll examine the rationale behind the initial monitoring recommendations, the concerns that prompted them, and the evidence that's now leading experts to reconsider the necessity of routine blood tests.

Why the Shift? Understanding Metal-on-Metal Hip Arthroplasties

Futuristic hip implant fading into a medical chart, symbolizing the evolving approach to monitoring metal-on-metal hip arthroplasties.

Metal-on-metal hip arthroplasties involve replacing the natural hip joint with an artificial joint made entirely of metal components. While these implants were initially praised for their durability and range of motion, it soon became clear that the friction between the metal surfaces could release metal ions—specifically cobalt (Co) and chromium (Cr)—into the body.

These metal ions can accumulate in the bloodstream and surrounding tissues, potentially triggering a range of adverse reactions. These reactions, collectively known as ARMD (adverse reactions to metal debris), can include:

Inflammation and pain around the hip joint
The formation of pseudotumors (fluid-filled masses) in the soft tissues
Bone damage (osteolysis)
Loosening of the implant
Systemic effects, such as skin rashes, neurological changes, and cardiac issues (though rare)

To detect these problems early, regular monitoring of blood metal levels became standard practice. The idea was that rising levels of cobalt and chromium could signal implant wear, the development of ARMD, or other complications, prompting further investigation and possible revision surgery. However, this approach has its limitations. Metal levels can vary widely from person to person, and some individuals may experience adverse reactions even with relatively low metal levels. Furthermore, the cost and inconvenience of routine blood tests can be a burden for patients.

The Future of Monitoring: A Personalized Approach?

The debate over blood metal level monitoring in MoM hip arthroplasties is far from settled. While the latest research suggests that routine annual testing may not be necessary for all patients, it's essential to remember that each individual's situation is unique. Factors such as implant type, patient activity level, and overall health can all influence the risk of complications and the need for monitoring.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.recote.2018.03.005, Alternate LINK

Title: Metal-On-Metal Surface Hip Arthroplasties. Is Annual Monitoring Of Blood Metal Levels Necessary?

Subject: Orthopedics and Sports Medicine

Journal: Revista Española de Cirugía Ortopédica y Traumatología (English Edition)

Publisher: Elsevier BV

Authors: D. Hernández-Vaquero, M. García-Pascual, S. Iglesias-Fernández, A. Escandon-Rodríguez

Published: 2018-11-01

Everything You Need To Know

Why were metal-on-metal hip arthroplasties initially considered a significant advancement in hip replacement surgery?

Metal-on-metal hip arthroplasties were initially viewed as a game-changer because they offered improved mobility and a better quality of life for individuals suffering from severe hip joint issues. These implants were praised for their durability and range of motion, leading to optimism about their long-term benefits compared to other types of hip implants. However, the subsequent discovery of potential adverse effects related to metal ion release tempered this initial enthusiasm.

What are the potential adverse reactions to metal debris (ARMD) associated with metal-on-metal hip implants, and how does this affect patients?

Adverse reactions to metal debris (ARMD) encompass a range of issues, including inflammation and pain around the hip joint, the formation of pseudotumors (fluid-filled masses) in the soft tissues, bone damage (osteolysis), loosening of the implant, and, in rare cases, systemic effects such as skin rashes, neurological changes, and cardiac issues. These reactions occur due to the accumulation of metal ions, like cobalt (Co) and chromium (Cr), released from the implant into the bloodstream and surrounding tissues. The variability in individual responses and metal levels makes managing and predicting ARMD complex.

What prompted the routine monitoring of blood metal levels in patients with metal-on-metal hip arthroplasties?

The routine monitoring of blood metal levels in patients with metal-on-metal hip arthroplasties was implemented to detect early signs of implant failure or adverse reactions to metal debris. The rationale was that rising levels of cobalt and chromium in the blood could indicate implant wear, the development of ARMD, or other complications, prompting further investigation and possible revision surgery. This proactive approach aimed to mitigate potential long-term health issues associated with metal ion release.

What factors might influence the risk of complications and the necessity for monitoring in patients with MoM hip arthroplasties?

Several factors can influence the risk of complications and the necessity for monitoring in patients with metal-on-metal hip arthroplasties. These include the specific implant type, as different designs may release varying amounts of metal ions. Patient activity level plays a role, as higher activity can lead to increased wear and metal release. Additionally, overall health status can affect how the body responds to metal ions. Individual patient characteristics are crucial in determining the appropriate monitoring strategy.

Why are experts reconsidering the necessity of routine blood tests for all patients with metal-on-metal hip implants, and what are the implications of this shift?

Experts are reconsidering routine blood tests due to growing evidence suggesting that annual testing may not be necessary for all patients. Research indicates that metal levels can vary widely among individuals, and some patients may experience adverse reactions even with relatively low metal levels. Additionally, the cost and inconvenience of routine blood tests can be a burden. This shift suggests a move towards a more personalized approach to monitoring, where decisions are based on individual risk factors rather than a one-size-fits-all approach. Factors such as implant type, patient activity level, and overall health will be considered to determine the need for monitoring.