ceramic on poly tha
play

Ceramic on Poly THA Darwin Chen, MD Assistant Professor Mount - PowerPoint PPT Presentation

Ceramic on Poly THA Darwin Chen, MD Assistant Professor Mount Sinai Medical Center Department of Orthopaedic Surgery Disclosures Monogram Orthopedics Consultant Why Bother With Anything But Ceramic on Poly THA? Ceramic liner fx


  1. Ceramic on Poly THA Darwin Chen, MD Assistant Professor Mount Sinai Medical Center Department of Orthopaedic Surgery

  2. Disclosures ▶ Monogram Orthopedics Consultant –

  3. Why Bother With Anything But Ceramic on Poly THA? Ceramic liner fx Metal-metal failure Taper corrosion – M on P Dual mobility disassociation Darwin Chen, MD Assistant Professor Mount Sinai Medical Center Department of Orthopaedic Surgery

  4. Trends in Total Hip Arthroplasty ▶ The fundamentals have not changed! ▶ Major challenge – implant longevity – Patients living longer • 1/3 of ♀ age 50 will live to be 100 – Expanding THA indications Sir John Charnley at his lathe, creating the • Younger, more active first THA implants • Higher functional demands/expectations

  5. Goals of the Bearing Articulation ▶ Minimize wear/biologically active debris ▶ Maximize hip stability ▶ Avoid bearing related complications ฀ Pre op ฀ Santoro, J

  6. Which Bearing Should I Use for My Patient? ▶ Age? ▶ Activity level? – Metal on poly – Ceramic on poly – Ceramic on ceramic – Metal on metal – Ceramic on metal Bedard, Callaghan, JoA 2017

  7. Osteolysis Directly Correlates With Wear Dumbelton JH, JoA 2002 ▶ “Threshold” for osteolysis is <0.1mm/yr (~650mm 3 ) Wilkinson JR, JOR 2005 Dowd, JBJS 2000 Looney RJ 2002

  8. Larger Heads = Better Stability Berry, 2005

  9. Larger Heads = Better Stability Howie, 2012 At one year following surgery: 28mm 36mm Primary 4.4% 0.8% Revision 12.2% 4.9% Overall 5.4% 1.3%

  10. Larger Heads = Better Stability Garbuz, 2012

  11. How is Metal on XLPE Doing? ▶ Pretty well! Feb 2013 – CoCr on XLPE, 7-10yr f/u – 28mm wear rate 0.012mm/yr – 32mm wear rate 0.01mm/yr – No osteolysis

  12. How is Metal on XLPE Doing? ▶ Pretty well! Sept 2016 – CoCr on Longevity XLPE, 28mm and 36mm – Mean wear @ 13 yrs = 0.05mm/yr – No difference between sizes – No osteolysis

  13. Taper Corrosion Cooper, 2012 ▶ Corrosion of CoCr head on Ti stem, ↑ Co/Cr ions ▶ An “emerging” problem with M on P ▶ Multifactorial Taper geometry, metallurgy, head size, assembly technique – ▶ Can cause mild to severe ALTR Late instability, abductor damage, osteolysis –

  14. Taper Corrosion ▶ Ceramic head significantly reduces potential for taper corrosion Significantly greater metal release (11x increase in Co and 3x increase in Cr) from a CoCr / CoCr interface – when compared to a Co-Cr / ceramic interface Corrosion can still occur – Cooper, JBJS(Am) 2013) ▶ When used with a titanium stem, no source of Co and Cr debris that can lead to ALTR

  15. Delta Ceramic ▶ Matrix composite ceramic ▶ Zirconia toughened, platelet reinforced, alumnia ceramic ▶ 82% alumina, 17% zirconia, 0.5% strontium aluminate, 0.5% chromium oxide

  16. Ceramic on Poly ▶ Avoid issues with hard-hard bearings ▶ Properties of ceramics further reduce wear characteristics of XLPE ▶ Delta ceramics – 50% stronger than alumina – More abrasion resistant than CoCr – 3x hardness of CoCr – Wettable – Biocompatible

  17. Wear Rate - Ceramic on Poly ▶ Simulator data shows clear advantage of C-on-P over M-on-P , 40-50% reduction Fisher, 2006 Galvin, Proc Inst Mech Eng 2010 Kim, 2005 CoCr Ceramic Total Linear Wear 1.21 mm 0.57mm p = 0.004 Linear Wear Rate 0.17 mm/yr 0.08 mm/yr p = 0.004 Volumetric Wear 744.7 mm 3 350.8 mm 3 p = 0.004

  18. Comparison Testing Bradgon 2006, Greenwald 2006, Manning 2005, Martell 2003, Zichner 1992,1997

  19. Ceramic Head Fracture ▶ Historically, ceramic head fracture was a significant clinical concern – Old aluminas were low density, coarse microstructure, not in compliance with today’s specifications ▶ Current alumnia and Delta ceramic substantially improved mechanical strength ▶ Biolox ceramic head fx rate 1 st gen Alumina – 0.026% – 0.014% 2 nd gen Alumina – 0.004% Delta Willmann, Clin Orthop 2000

  20. Ceramic Head Fracture ▶ Delta head fractures are negligible with 32/36 heads

  21. Ceramics – Less Risk of PJI? ▶ In theory, ceramics have less bacterial biofilm formation due to decreased surface roughness and molecular composition ▶ Reduced wear = reduced bio-burden of PE particles, less inflammation ▶ No Co, Cr ion release – no immune suppression? Ceramtec, Inc.

  22. Ceramics – Less Risk of PJI? March 2017 ▶ Medicare database (315,784 patients) ▶ C-P and C-C exhibit lower risk of infection comparted to M-P (C-P hazard ratio 0.86, p=0.001. C-C hazard ratio 0.74, p=0.01) ▶ C-P reduced risk of dislocation and mortality (HR 0.81, p<0.001, HR 0.92. p<0.001)

  23. Conclusions ▶ In 2018, ceramic on poly is the best choice for most THAs ▶ Excellent wear properties ▶ Eliminates the metal ion problem ▶ No squeaks, negligible fracture risk ▶ Reduced PJI? ▶ Forgiving, no change in technique

  24. Thank You Darwin Chen, MD Assistant Professor Mount Sinai Medical Center Department of Orthopaedic Surgery

Download Presentation
Download Policy: The content available on the website is offered to you 'AS IS' for your personal information and use only. It cannot be commercialized, licensed, or distributed on other websites without prior consent from the author. To download a presentation, simply click this link. If you encounter any difficulties during the download process, it's possible that the publisher has removed the file from their server.

Recommend


More recommend