OrthopaedicPrinciples.com

Integrating Principles and Evidence

Integrating Principles and Evidence

  • Home
  • Editorial Board
  • Our Books
    • Evidence Based Orthopaedic Principles
  • Courses
  • Exams
  • Reviews
  • Live Program
  • Contact

Dual Mobility Cups in Total Hip Replacement

Courtesy: Prof Jean Alain Epinette, Lelle, France

Black Yellow Modern Online Business Webinar Invitation – 1

Discussion on Dual Mobility Cups in Hip Replacement

Key Question: Is Dual Mobility (DM) a reasonable option for all hip replacements?

  • The new construct (since 2000) has changed perspectives on hip replacements.

  • It performs well in both young and elderly patients, for both primary and revision cases.

  • Cost-effectiveness is an important benefit of DM cups.

  • Modularity is improving, making DM cups more adaptable.

  • The hip-spine relationship must be considered when choosing implants.


Need for DM Cups in Primary Hip Replacements

  • Instability is a leading cause of revision surgery, as seen in:

    • Swedish Registry

    • Australian Registry

    • UK studies

  • Both elderly and young patients are affected by instability.

  • A 24-year prospective study in primary hips (over 2,000 cases) showed:

    • Higher dislocation rates in elderly patients (>70 years).

    • Higher revision rates for younger patients (<60 years).

  • Survival curves showed worse outcomes in young patients compared to older ones.


Modern DM Cups as a Reliable Option

  • Initial challenges with early DM cups (1974, French SHB studies)

    • Originally considered only for salvage procedures.

    • French health authorities limited indications to elderly and high-risk patients.

  • Issues with classic DM cups:

    • Loosening (3%)

    • Intraprothetic dislocation (5%)

    • Wear-related failure (1.6%)

  • Advancements in modern DM cups have addressed these issues:

    • Better fixation with improved substrates and bone ingrowth.

    • Enhanced design reduces intraprosthetic dislocations.

    • Newer bearing surfaces improve wear resistance.


Long-Term Results of Modern DM Cups

  • A 10-year study in young patients (<55 years) showed:

    • Survival rate of 100% at 4 years for younger patients.

    • Lower dislocation rates (<1% in primary, 3.5% in revisions).

  • A literature review (Stroh et al.) found:

    • DM dislocation rate <1% for primaries, 3.5% for revisions.

    • Fixed-bearing dislocation rates: 2-7% (primary) and up to 16% (revision).

  • A Canadian study further supported the reliability of DM cups.

  • Newer DM constructs resolve limitations of earlier designs.


Use of DM Cups in Young Patients (<55 years)

  • Multicenter study (France + USA) followed young patients for 20 years.

  • 747 primary hip replacements in 600 patients.

  • Findings:

    • No cases of dislocation or instability.

    • Less than 2% complication rate (loosening, impingement, etc.).

    • Survival rate of 90.8% at 19 years.


DM Cups in Revision Cases

  • If DM cups are effective in primary THA, can they be used in revisions?

  • Advantages of DM cups in revisions:

    • Better fixation with screw options.

    • Enhanced stability due to larger head size.

    • At least 50% host bone contact is required for success.

  • Review of literature shows:

    • DM dislocation rate in revisions: 3.5%.

    • Fixed-bearing dislocation rate in revisions: up to 16%.


Economic Benefits of DM Cups

  • Hip dislocations have a high financial impact due to:

    • Hospital readmissions, revision surgeries, and rehab costs.

  • Cost-effectiveness study in France:

    • If DM cups were used universally, France could save €50+ million per year.

    • Potential savings of €100 million in an optimal scenario.


Future Developments: Modular DM Cups

  • New modular DM cups provide:

    • Customizable options for both primary and revision hip replacements.

    • Better adaptability to patient anatomy.

    • Improved longevity and performance.


  • DM cups are a reliable solution for both primary and revision hip replacements.

  • They reduce dislocation rates, improve patient outcomes, and offer cost savings.

  • New modular designs make DM cups even more versatile.

  • Considering the strong evidence, the question is: Should everyone receive a DM cup in hip replacements?

Key Questions in Dual Mobility Cups (DMC)

  1. Is the modular DMP truly dual mobility?

    • It lacks an elevated rim, which could impact mobility.

  2. Potential coupling issues between C and titanium

    • Could lead to risks, including adverse reactions.

  3. The real benefit of screws in the axis of the stress line

    • Investigating the stability and fixation advantages.


Study on Primary Cases with Modular Dual Mobility

  • Study Type: Prospective, observational, 5-year study across 5 centers in Europe & the US.

  • Participants: 300+ patients, with a minimum age of 48 years.

  • Findings:

    • No dislocations or intraprosthetic dislocations.

    • 97% survivorship for all causes.

    • 99% survivorship at 5 years when looking only at acetabular component revisions.


Study on Modularity in Revision Cases

  • Published Study: Journal of Arthroplasty, minimum 5-year follow-up of 102 modular titanium MDM cups.

  • Findings:

    • Only 5 dislocations (4 from revision cases).

    • 5.6% dislocation rate in revision cases, significantly lower than fixed bearings.


Hip-Spine Relationship & Dislocation Risk

  • Older Patients: Increased spine rigidity may lead to dislocation.

  • Younger Patients:

    • A 50-year-old may experience instability 20 years later.

    • Using dual mobility early may prevent future instability.


Common Controversies in Dual Mobility Cups

  1. Does double articulation lead to double wear?

    • Studies on 40 retrieved polyethylene liners (mean 8 years) show wear rates similar to conventional metal-polyethylene bearings while providing better retention and stability.

  2. Modular systems and ion release concerns

    • Examining adverse effects related to cobalt and chromium ion release.

  3. Highly cross-linked polyethylene – is it a decisive factor?

    • Comparing different polyethylene treatments (annealed vs. remelted).


Double Articulation & Wear Performance

  • Testing Conditions:

    • Worst-case scenarios examined, including impingement and abrasion.

  • Findings:

    • Even under high-wear conditions, the highest-wearing dual mobility group wore 75% less than single articulation conventional polyethylene bearings (published in Journal of Arthroplasty).


Ion Release & Biological Concerns

  • Study: Prospective analysis (2012-2014) on 40 CrCo MDM cases presented at the 2021 World Arthroplasty Congress.

  • Findings:

    • No adverse local reactions.

    • All cobalt and chromium levels were under 1 microgram per liter.

    • Additional studies confirm average cobalt & chromium levels remain below 0.7 micrograms, with no revisions due to allergic reactions.


Clinical Outcomes in Young Patients

  • Study: 5-year multicenter international study using MDM with highly cross-linked polyethylene.

  • Findings:

    • Only 2 revisions due to anterior impingement.

    • Zero failures due to acetabular modularity.

    • 99% survival at 5 years.

    • No intraprosthetic dislocations, wear, or loosening.


Highly Cross-Linked Polyethylene Considerations

  • Comparison of Annealed vs. Remelted Polyethylene:

    • Annealed: Maintains 100% elasticity.

    • Remelted: Loses 35% mechanical strength and has poor fatigue resistance.

    • Conclusion: Remelted polyethylene is not recommended for dual mobility cups due to poor fatigue test results and loss of elasticity.


Registry Reports & Infection/Fracture Risks

  • Comparison of Dual Mobility (DM) vs. Fixed Bearings:

    • Infection and periprosthetic fracture rates – No significant difference.

    • Dislocation rates – Significantly lower in DM cases.


Future of Dual Mobility Cups

  • Published Summary: EFORT Open Reviews.

  • Key Takeaways:

    • Young patients are increasingly at risk for revision.

    • DM cups prevent major complications like instability and wear.

    • Proven long-term outcomes, even in younger patients.

    • Cost Savings: France could save €50 million per year with wider DM use.

Post Views: 1,007

Related Posts

  • Orthobiologics in Sports Medicine

    Courtesy: Dr Anthony Luke, UCSF San FRancisco

  • Total Hip Replacement

    Courtesy: RCSI

  • Dual Mobility Components in Total Hip Arthroplasty

    Courtesy: PrabhuDev Prasad Purudappa, MD, MS, Assistant Professor, Boston University and Attending Orthopaedic Surgeon, VA…

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Follow Us

instagram slideshare

Categories

  • -Applied Anatomy
  • -Approaches
  • -Basic Sciences
  • -Cartilage & Meniscus
  • -Classifications
  • -Examination
  • -Foot and Ankle
  • -Foot and Ankle Trauma
  • -FRCS(Tr and Orth) tutorials
  • -Gait
  • -Hand and Wrist
  • -Hand and Wrist Trauma
  • -Hand Infections
  • -Hip and Knee
  • -Hip Preservation
  • -Infections
  • -Joint Reconstruction
  • -Knee Arthroplasty
  • -Knee Preservation
  • -Metabolic Disorders
  • -Oncology
  • -OrthoBiologics
  • -OrthoPlastic
  • -Paediatric Orthopaedics
  • -Paediatric Trauma
  • -Patellofemoral Joint
  • -Pelvis
  • -Peripheral Nerves
  • -Principles
  • -Principles of Surgery
  • -Radiology
  • -Rheumatology
  • -Shoulder and Elbow
  • -Shoulder and Elbow Arthroplasty
  • -Spine Deformity
  • -Spine Oncology
  • -Spine Trauma
  • -Spine, Pelvis & Neurology
  • -Sports Ankle and Foot
  • -Sports Elbow
  • -Sports Knee
  • -Sports Medicine
  • -Sports Medicine Hip
  • -Sports Shoulder
  • -Sports Wrist
  • -Statistics
  • -Technical Tip
  • -Technology in Orth
  • -Trauma
  • -Trauma (Upper Limb)
  • -Trauma Life Support
  • -Trauma Reconstruction
  • Book Shelf
  • Book Shelf Medical
  • Careers
  • Case Studies and Free Papers
  • DNB Ortho
  • Evidence Based Orthopaedic Principles
  • Evidence Based Orthopaedics
  • Exam Corner
  • Fellowships
  • Guest Editor
  • Guest Reviews
  • Image Quiz
  • Instructional Course Lectures
  • Journal Club
  • MCQs
  • Meetings and Courses
  • Multimedia
  • News and Blog
  • Plaster Techniques
  • Podcasts
  • Public Health
  • Rehabilitation
  • Research
  • Shorts and Reels

Book Shelf

Kendall’s Muscle Testing and Function 6th Edition

Kendall’s Muscle Testing and Function 6th Edition

By admin Leave a Comment

Get Book Kendall’s Muscles: Testing and Function, with Posture and Pain, 6th Edition, transforms this landmark Physical Therapy classic to prepare you for unparalleled clinical success in today’s practice. Timeless coverage of manual muscle testing, evaluation, and treatment meets the latest evidence-based practices, engaging imagery, and dynamic digital resources to create a powerful resource you […]

Popular Posts

  • Bone Screws in Orthopaedic Surgery
  • Silverskold Test
  • Piriformis Syndrome
  • Blood Supply of Long Bone
  • Movements of the Thumb

Recent Comments

  • RAJATABHA BISWAS on NUH Fellowship in Singapore
  • Runj on ESSKA Congress 2026
  • OT Hand Therapist on Interosseous Muscles Of The Hand
  • Badreddine on Rockwood and Green Fractures in Adults and Children- 10th Edition
  • Prof Dr P.sridhar MS Ortho,D Ortho on Rockwood and Green Fractures in Adults and Children- 10th Edition

Exam Corner

FRCS Orth Exam- Knee Arthroplasty

Courtesy: Zaid al Rab, FOunder, OrthoPass

MCQ Exam for the FRCS Orth 1

Courtesy: Zaid al Rub, Founder, OrthoPass

Postgraduate Entrance Exam Set 3

Get explanatory answers from our book

Postgraduate Entrance Exam Set 2

Get explanatory answers from our book

Main Menu

  • Orthopaedic Principles
  • Editorial Board
  • Orthopaedic Principles-A Review

Recent Posts

  • Anterior Tibial Tendon Tears
  • Endoscopic Lumbar Microdiscectomy
  • RAMP Lesion of the Knee
  • Osteochondritis Dissecans of the Knee
  • Dual Mobility Cups in Total Hip Replacement

Links

  • Join Our Editorial Board
  • Journals
  • Weblinks
  • Submit Your Conference
  • Disclaimer
Copyright@orthopaedicprinciples.com. All right rerserved.