Highly Crosslinked UHMWPE In THR TKR ARTHROPLASTY (Polyethylene ),DR.SANDEEP AGRAWAL Agrasen Fracture Hospital Gondia Maharashtra Crucial for Revision Joint Replacemant Surgeries, THR(Total Hip Replacement ),TKR (Total Knee Replacemant ), Hip Knee Pain

1. Highly Crosslinked UHMWPE
In THR TKR ARTHROPLASTY
(Polyethylene )
DR.SANDEEP AGRAWAL
Consultant Orthopaedic Surgeon
Agrasen Fracture Hospital
Gondia
Maharashtra

2. POLYETHYLENE

3. Timeline of Development of UHMWPE

4. UHMWPE

5. Naming of UHMWPE
(Hoechst/Celanese, 1996)
 GUR (Granular, UHMWPE, Ruhrchemie)
 A,B,C,D HP (eg. GUR 1050, GUR 4150 HP)
 A: 1-Germany, 4-USA, Texas
 B: 1-Ca stearate, 0-none
 C: 2- MW=2-4million, 5- MW>4million
 D: 0 no meaning
 HP: High Purity, meets the ASTM requirement
(American Society for Testing and Materials)

6. Contemporary Highly
Crosslinked UHMWPE

7. Manufacturing of UHMWPE Implants

9. Irradiation in Air
MW ↓→ strength ↓

10. Irradiation in Inert Air

11. DurationTM Stabilization Process
(1995, Howmedica)
Precursor of Highly crosslinked
Stabilization by heating 37-50 ˚C for 144 hrs
Volumetric wear 32% less than air-irradiated control

12. Longevity Crosslinked Polyethylene
Polyethylene is a part
crystalline, part
amorphous structure
Crystalline
Amorphous Free Radical
Site
Heated to Melt the Crystalline Phases
Heat
Heat
Cooled slowly to return to its original structure
Crosslink

13. Comparision of
Highly Crosslinked UHMWPE
Kyocera,
Osteonics Zimmer Zimmer Japan
AeonianTM
Bar stock
35KGyGamma
irradiation
Machined after XL
Pack in Nitrogen
25-40 kGy
Gamma
Sterilization
DePuy-
Dupont Zimmer
Smith &
Nephew

14. Alternative Bearing Material seek improved
function, longer survivorship
Ceramic head- on-metal
cup
Michael Piechocki, Fisher J, Orthopedics Today International, July/August, 2006, p17-8

15. The Basis for a Second-generation Highly
Crosslinked UHMWPE
 First generation Highly Cross-linked
(UHMWPE)
 Melted highly crosslinked polyethylene may
be susceptible to fatigue cracking, and
 Annealed highly crosslinked polyethylene
may be susceptible to in vivo oxidation.
Dumbleton JH, D'Antonio JA, Manley MT, Capello WN, Wang A.
Clin Orthop Relat Res. 2006 Sep 28

16. The Basis for a Second-generation Highly
Crosslinked UHMWPE (X3 HXPE)
 (X3 HXPE) uses a sequential irradiation and
annealing process.
 Mechanical strength properties preserved with the highest
survivorship in functional fatigue testing.
 Free radical content is low, and performance under
accelerated aging is the same as virgin UHMWPE
 Crystallinity, density, and tensile strength was unchanged
by oxidative challenge.
 Volumetric wear rate very similar to metal-on-metal
articulations
 Wear particles were the same size as those produced from
conventional UHMWPE.
Dumbleton JH, D'Antonio JA, Manley MT, Capello WN, Wang A.
Clin Orthop Relat Res. 2006 Sep 28

17. Alternative Bearing Material seek improved
function, longer survivorship
Ceramic head- on-metal
cup
Michael Piechocki, Fisher J, Orthopedics Today International, July/August, 2006, p17-8
(X3 HXPE)