Published 9/1/2012

AAOS Resources on Metal-on-Metal Bearings

Metal on Metal – An overview of AAOS communications
The AAOS believes that patient safety must be the highest priority, and is concerned about patients’ health and outcomes. The AAOS takes every opportunity to provide learning and educational opportunities for members, patients, the media and the public.


  • Since 2007, AAOS has offered numerous educational papers, posters and scientific exhibits with the latest research and studies on metal-on-metal (MoM) arthroplasty at each AAOS Annual Meeting. (See listing below for materials from the 2010, 2011, and 2012 meetings.)
  • The AAOS website (www.aaos.org) has more than 400 references (AAOS Now articles, information statements, member alerts, orthopaedic journal articles, etc) on MoM-related information.

Education Programs

  • Educational webinar—AAOS Total Hip Arthroplasty: Is there a Metal-on-Metal Bearings Controversy (December 2010) More than 400 orthopaedic surgeons participated.
  • Course—Sept. 8–10, 2011—AAOS/AAHKS Total Hip Arthroplasty: From Primary to Revision

2012 Annual Meeting

  • SE03: Imaging of MoM Hip Retrievals Offers a New Lexicon of Hip Wear Phenomena Common to This Class of Devices
  • SE08: Effect of Computer-Assisted Navigation on Dislocation After Primary Total Hip Arthroplasty
  • SE06: Hip Society: Algorithmic Approach to Diagnosis and Management of Metal-on-Metal Arthroplasty
  • SE09: Groin Pain After Total Hip Arthroplasty
  • SE12: Pathologic, Serologic, and Tribologic Findings in Failed Metal on Metal Total Hip Arthroplasty
  • SE17: Analyzing Failure of Total Joint Arthroplasty to Enable Future Success: The Role of a Multicenter Retrieval Program


  • Worldwide Perspective on Alternate Bearings
  • Hot Topics in Joint Preservation and Joint Arthroplasty
  • Metal on Metal Hip Replacement: Current Status and Recommendations For Patient Management
  • Joint Replacement Registries: Using the Data to Improve Patient Outcomes


  • ICL 221 The Painful Metal on Metal Hip Arthroplasty: Evaluation and Management
  • ICL 241 Revision in Total Hip Arthroplasty: Understanding and Management of Osteolysis


  • 308—Pseudotumour Following Metal on Metal Hip Replacement can Progress after Revision Surgery
  • 309—Metal Ion Analysis in Patients with Metal-on-Metal Hip Replacements: Whole Blood vs. Serum
  • 310—Five-year Metal Ion Levels After Metal-on-Metal Total Hip Arthroplasty (THA): A Prospective, Randomized Trial
  • 311—Balancing Competing Considerations for Optimal Orientation in 36-mm Metal-on-Metal Total Hips
  • 315—High Serum Metal Ions (> 7µG/l) Cannot Be Used as an Indirect Screening Test in Metal on Metal Bearing Hip Surveillance
  • 556—Change in Serum Metal Ion Concentrations Following Revision of Metal on Metal Total Hip Arthroplasty
  • 558—Are Metal Ion Levels a Useful Trigger for Surgical Intervention?
  • 559—Survivorship and Revision Analysis Among Primary Metal on Metal Total Hip Arthroplasty Using 36 mm Diameter Heads
  • 562—The Main Issue of Large Diameter MoM Total Hip Arthroplasty: The Taper Junction
  • 566—Revision for Failed Metal on Metal Hip Replacement
  • 569—The Clinical Implications of an Elevated Blood Metal Ion Result post MoM Hip Resurfacing
  • 647—Pseudotumor in Metal-on-Metal Hips: Can a Blood Metal Ion Cut-off Level Indicate When to Perform MRI?
  • 649—2D Measurements of Cup Orientation in MoM Hips are Highly Inaccurate Compared to 3D-CT
  • 656—What are Safe Upper Limits in Well Functioning Resurfaced Hips?
  • 658—Risk Factors for Pseudotumor in Metal-on-Metal Hip Replacements


  • P001—A Comparison of Metal on Metal to Metal on Highly Cross-linked Polyethylene Total Hip Replacements
  • P004—MRI Reveals a High Prevalence of Pseudotumours Adjacent to Well Functioning Metal-on-metal Hip Arthroplasties
  • P005—Retrieval Analysis of 130 Metal-on-Metal Hips Showed that the ASR is Higher Wearing when Compared to the BHR
  • P009—Synovial Fluid Analysis for Select Cytokines May Assist in Stratifying the Severity of ALTR in Failed MoM Hips
  • P011—Two-year Follow Up of Pseudotumor Diagnosed in Metal-on-Metal Hip Arthroplasties
  • P013—Ellipsoidal Wear Zones on MoM Heads Show Distinct Damage Patterns
  • P023—Retrieved Metal on Metal Heads Convey Details of In Vivo Articulation and Bearing Contact
  • P044—Results of a Two-Year, Prospective, Randomized, Controlled Study of Metal-Ion Release following MoM THA
  • P050—High Failure Rates with a Large Diameter Hybrid Total Hip Replacement
  • P064—Poor Short-Term Outcomes with a Contemporary Metal on Metal Total Hip Arthroplasty System
  • P068—Metal on Metal Local Tissue Reaction is Associated with Corrosion of Head Taper Junction
  • P071—The Outcome of Metal on Metal Bearing Surfaces in Hip Arthroplasty
  • P092—Cementless THA with LDH MoM Heads - Short Term Survivorship of 8,059 Hips from the Finnish Arthroplasty Register
  • P331—Metal on Metal Reverse Total Shoulder Prosthesis for Shoulder Reconstruction in Young Patients

2011 Annual Meeting

  • SE01—The Immunopathology of ALVAL
  • SE03—Understanding Why Metal-on-Metal Hip Fail: The London Implant Retrieval Centre
  • SE05—Incidence, Recognition, and Treatment of Pseudotumors in THA: Does Bearing Type Make a Difference?
  • SE06—Inflammatory Pseudotumours Associated with Metal-on-Metal Hip Replacement
  • SE07—Metal-on-Metal Bearing Failure: Gender Differences as Compared with Metal-on-Improved Polyethylene
  • SE14—Technical Challenges, Pre-operative Planning and Outcomes of THA in Down Syndrome Patients
  • SE16—Prevalence of Primary Metal-on-Metal Bearings in the United States
  • SE30—Tissue Reactions to Prosthetic Metal Wear Debris: Studies of Osteolysis, Pseudotumor and ALVAL
  • SE41—FDA Today: Latest Regulatory Perspectives Regarding Metal-on-Metal Joint Replacement


  • AAOS/ORS Combined Symposium—Research for Immediate Translation to Orthopaedic Practice
  • Current Controversies in Total Joint Arthroplasty (E)
  • Managing Complications after Primary Total Hip Arthroplasty in Your Practice (V)


  • 201 High Performance Hip Replacement: What Is It? Who Is the Right Candidate?
  • 209 Elbow Arthroplasty: Lessons Learned from the Past and Directions for the Future
  • 221 Controversies in Complex Primary and Revision Total Hip Replacement
  • 341 Technology 2011: Alternative Bearing Surfaces: The Good, Bad and Indifferent
  • 365 Hip Replacement or Hip Resurfacing: What’s Best for My Young Patients?
  • 401 Revision in Total Hip Arthroplasty: Understanding and Management of Osteolysis
  • 461 Primary Total Hip Arthroplasty: The Basics


  • 032—Neck Narrowing In Hip Resurfacing Is Associated With Wear
  • 033—Retrieval Analysis of 240 Metal-on-Metal Hip Components: Stemmed Versus Resurfacing Hip Arthroplasty
  • 035—Failure Causes and Modes of Modern Metal-on-Metal Hip Resurfacing Implants
  • 036—A Review of Hip Resurfacings Revised for Unexplained Pain
  • 038—The Incidence of Adverse Tissue Reactions in a Multicentre Study Involving 4226 Hip Resurfacings
  • 045—The Effect of Patient Selection and Surgical Technique on results of Metal-on-Metal Hip Resurfacing
  • 061—Short-Term Results of Large Diameter Metal on Metal Total Hip Arthroplasty
  • 062—Serum Cobalt and Chromium Levels After Metal-on-Metal Hip Resurfacing: Minimum 5 Year Analysis
  • 063—Osteolysis Following Cementless Total Hip Arthroplasty with a Contemporary Metal-on-Metal Bearing
  • 064—Use of Ultrasound in the Diagnosis of Adverse Reaction to Metallic Debris in MoM Hip Replacements
  • 065—Inflammatory Cytokines are Elevated in Patients with Adverse Reactions to Metal-on-Metal THAs
  • 066—Pathologically Confirmed Metal-on-Metal THA Adverse Local Tissue Reactions from One Center
  • 067—Clinical and Wear Analysis of 276 Failed Large Diameter Metal-on-Metal Hip Components
  • 068—The Occurrence of Edge Loading in Metal on Metal Hips: Low Clearance is a New Risk Factor
  • 069—Volumetric Wear of MoM Hips does not Correlate with Extent of Tissue Destruction at Revision.
  • 070— Implant Survival of Metal-on-Metal Hip Resurfacing: a Systematic Review
  • 071—Large Diameter Modular Metal-on-Metal Total Hips: Assessing Soft Tissue Adverse Events
  • 073—Serum Metal Ion and Ultrasound Assessment of Asymptomatic Metal-on-Metal Hip Replacement
  • 074—Outcomes and Pathomechanics of Adverse Local Tissue Reactions (ALTR) in Metal-Metal Bearings
  • 360—Total Hip Replacement Using a Short Uncemented Stem


  • P014—MRI in THA: A Prospective Blinded Comparison of MRI with Histopathology of Retrieved Tissue
  • P041—Outcome of Metal on Metal Articulation in Primary Conventional THA: Analysis of 17,775 Procedures
  • P043—Performance of the ASR in Resurfacing and Conventional Primary THA: Analysis of 5563 Procedures
  • P057—Metal-on-Metal Revisions: A Review of Causes, Outcomes and a High Incidence of Early Failure
  • P064—Randomised Controlled Trial Comparing Cemented Stem Behaviour Following Large MOM and MOP THA
  • No. P071—Complications Associated with Metal Ion Toxicity - A Population Study of Hip Resurfacing Patients
  • P074—Rim Loaded MoM Hip Prostheses: Volumetric Wear is Increased by Increasing Bearing Diameter
  • P076—Early Failure of DePuy ASR XL Total Hip Arthroplasty
  • P082—Are Metal Ions from Metal-on-Metal Hip Arthroplasty Detrimental to Spermatozoa in Young Patients?
  • P103—Modern Ceramic on Ceramic Total Hip Arthroplasty in Patients Under 50: Minimum 10 Year Follow-up
  • P375—Controlled ROM of a New Metal-on-Metal Lumbar TDR Placed by Lateral Approach

2010 Annual Meeting

  • SE15—Inflammatory Pseudotumours Associated With Metal-on-Metal Hip Replacement
  • SE18—Identifying and Offsetting Risk Factors for Metal-on-Metal Hip Resurfacing
  • SE22—Metal Hypersensitivity Testing in Total Joint Arthroplasty Patients
  • SE23—Resurfacing Versus Conventional THA: Comparative Clinical and Basic Science Studies
  • SE24—Metal-on-Metal Bearings in Total Hip Arthroplasty: Minimum 2-Year Follow-Up
  • SE28—Incidence, Recognition, and Treatment of Metal Pseudotumor Reactions in Hip Arthroplasty


  • Great Debates in Total Hip Arthroplasty: Case Based Discussions (L)
  • High Performance Hip Replacement: What Is It? Who Is the Right Candidate? (O)


  • 153—Primary Total Hip Arthroplasty: The Basics
  • 201—Hip Replacement or Hip Resurfacing: What's Best For My Young Patients?
  • 253—Osteonecrosis of the Hip: Joint Preservation and Reconstruction
  • 262—Biological Implants
  • 301—Controversies in Complex Primary and Revision Total Hip Replacement
  • 341—Technology 2010: Alternative Bearing Surfaces: The Good, Bad and Indifferent
  • 361—Revision in Total Hip Arthroplasty: Understanding And Management of Osteolysis


  • 001—Large Head Metal on Metal Total Hip Arthroplasty with Monoblock Cup May Not Be As Good As Advertised
  • 002—Correction of Femoral Acetabular Impingement at the Time of Primary Large Diameter Metal-Metal THA
  • 003—In Vitro Analysis of Retrieved Ceramic Implants for Squeaking
  • 004—Osteolysis After Al-on-Al Ceramic Bearing Cementless THA in Pts < 45 years With Femoral Head AVN
  • 005—Ceramic on Metal versus Metal on Metal Clinical and Metal Ion Results of a Prospective FDA RCT
  • 006—A Review of 585 Serum Metal Ion Results Post Hip Resurfacing: Cup Design and Position is Critical
  • 007—High Blood Cobalt Levels Can Be Used to Predict Failure of Metal On Metal (MOM) Hips
  • 008—Metal Ion Levels in Maternal and Placental Blood Following Metal-on-Metal Arthroplasty
  • 009—Placental Regulation of Metal Transfer in Patients with Metal-Metal Surface Replacement Arthroplasty
  • 010—Histological and Immunohistochemical Response in Tissue Around Metal on Metal Hips-the UK Experience
  • 011—High Early Revision Rate Due to Pseudotumor Formation in Metal-on-Metal Large Head Diameter THA
  • 012—The Incidence of Adverse Reactions to Metal Debris (ARMD) Following Hip Resurfacing
  • 013—The Role of Acetabular Component Positioning in the Development of Inflammatory Pseudotumours
  • 014—Corrosion in Retrieved High Carbon Cobalt Chrome Hips
  • 015—Second Generation Metal-on-Metal Total Hip Replacements at 13-Year Follow-up
  • ARH 1 ALTERNATE—Interpretation of Metal Ion Levels after Metal-On-Metal Hip Resurfacing
  • 311—Range of Motion after Stemmed Total Hip Arthroplasty and Hip Resurfacing: A Clinical Study
  • 663—Inflammatory Pseudotumours Following MoM Hip Resurfacing, a 1419 Patient Follow-up Study
  • 664—Increased Wear of Metal on Metal Hip Resurfacing Implants Revised due to Pseudotumours
  • 665—A Survey on the Incidence of Pseudotumours with MOM Hip Resurfacings in Canadian Academic Centres
  • 666—Rise of Chromium Ion Levels in Patients Undergoing Staged Bilateral Hip Resurfacing
  • 667—In Vivo Edge Loading During Functional Activities in MoM Hip Resurfacing Patients with Pseudotumours
  • 668—Groin Pain Following Hip Resurfacing. A Case Control Study
  • 671—Metal-on-Metal Hip Resurfacing - The First 100 Hips with a Minimum 10 Year Follow-up
  • 672—Eight Year Clinic Outcome of the Metal-on-Metal Hybrid Hip Surface Replacement
  • 673—Randomised Study Comparing THA and Hip Resurfacing
  • 675—Spinal & Pelvic Motion after Hip Resurfacing Arthroplasty and Metal on Metal Total Hip Arthroplasty


  • P003—Blood Management Comparison Analysis between Unilateral and Bilateral Hip Surface Replacement
  • P032—Gait Symmetry: Hip Resurfacing vs. Total Hip Arthroplasty
  • P036—Concentrations of Cobalt and Chromium in Blood in Patients Managed with Total Hip Arthroplasty(THA)
  • P037—Clinical Follow-up and Metal Ions in Blood of Patients with Hip Resurfacing
  • P053—Do Serum Metal Ions In MOM Hip Resurfacing Change Over Time And Do They Differ From 28mm MOM THAs?
  • P056—Pre-revision CT Measured Cup Angles are Related to Wear of Retrieved Metal on Metal (MOM) Hips
  • P092—Unexpected Early Failure Rate with One Metal-on-Metal Total Hip Arthroplasty
  • P094—Optimum Acetabular Component Position for Reduced Ion Levels in Hip Resurfacing
  • P095—Early Results of Large Diameter Metal on Metal THA
  • P100—Interpretation of Metal Ion Levels after Metal-On-Metal Hip Resurfacing
  • P109—Metal-on-Plastic Total Hip Replacements: Does the Femoral Head Wear?
  • P110—Concern with Titanium Nitride Coated Total Joint Replacement Components
  • P567—Large-Diameter-Head Metal-on-Metal Total Hip Replacement for Development Hip Dysplasia


Advocacy Now

Member Alerts

Headline News Now

  • In 2012 (through Aug. 24), the following issues of AAOS Headline News Now included information on MoM hip implants: Aug. 6; June 4, 22, 25, 27, 29; April 4, 11, 27; March 9, 14; Feb. 29
  • The following issues of AAOS Headline News Now in 2011 included information on MOM hip implants: Dec. 12, 28; Nov. 30; Oct. 12, Sept. 19, Aug. 8, 10; June 15, 17; May 9, 11, 18; Feb. 11

Technology Overview

  • In December 2011, the AAOS Board of Directors approved a Technology Overview on Modern Metal-on-Metal Hip Implants

National Media

  • AAOS issued a media advisory to the consumer and trade media in October 2010 with information about a MoM case report published in the American version of the Journal of Bone and Joint Surgery (JBJS). www6.aaos.org/news/pemr/releases/release.cfm?releasenum=934
  • The Academy issued a media advisory to the consumer and trade media in February 2011 with information on the new MoM public communication released from the FDA. www6.aaos.org/news/pemr/releases/release.cfm?releasenum=976
  • AAOS hosted a media expert roundtable for onsite media at the 2011 Annual Meeting, where on-site journalists could listen and ask questions of Joshua J. Jacobs, MD, AAOS first vice-president.
  • In May and June 2011, when the FDA made the announcement of required post-market surveillance for all metal-on-metal hip arthroscopy devices, the AAOS posted an item for the media under the AAOS News Bureau.
  • Wrote a letter to the editor of the New York Times, which was published, in response to the article “Hip Implant Complaints Surge, Even as the Dangers Are Studied,” August 23, 2011.
  • Wrote a memo to Barry Meier in response to the article “The High Cost of Failing Artificial Hips,” Dec. 28, 2011.
  • Held an AAOS expert roundtable for onsite media at the 2012 Annual Meeting.

Public and Patients

  • In February 2011, AAOS sent a letter to more than a dozen medical specialty societies informing them of the latest communication released from the FDA and encouraging them to share it with their membership.
  • Created two areas on the public education website www.orthoinfo.org citing potential questions and answers for patients who may have a metal on metal hip. Content continues to be updated as appropriate. Provides links to the FDA, media materials, and patient information created by a consortium of specialty societies and AAOS.