Metal on Metal hip replacements have a long story marred by many ugly incidents and experiences. An insiders presentation on the catastrophic ASR failures that rocked the orthopaedic community.

1. Lessons learnt from MOM
disaster
Dr Vaibhav Bagaria
MBBS, MS, FCPS
Joint Replacement Surgeon,
CARE hospital & ORIGYN Clinic
Nagpur, INDIA

2. Lessons Learnt!
Technology
Metallurgy
Technique
Personal, Philosophical & other Funda’s

3. what did we learn?
Harmful effects of metal ions in body.
There are still unknown unknowns.
Tips tricks traps of revision arthroplasty
Gained experience on what to do when things
go horribly wrong for surgeons.

4. remember this image!

5. what was MOM?
First attempted in 1920’s, 30 designs so far,
multiple failure.
Bearing surface always ignited interests
because of less wear and hence increased
longevity
Renewed interests with good results with BHR
in 1990’s. Good biomechanics, bone
preservation, hard bearing, marketed to young
active population.

6. Most famous mom: AsR
•
Depuy product
•
First Released in 2003.
•
Withdrawn from Australia in Dec 2009
•
World-wide recall Aug 2010

7. Asr: good
•
Bone Preserving.
•
?? Increased ROM
•
Better Wear Characteristic in vitro.
•
Good Instrumentation.
•
Compatible/easily convertible to THR

8. what happened?

9. evaluation
History.
Examination
MRI
Blood Ion levels
Aspiration

10. Personal experience
•
10% catastrophic failure
•
10- 20 % Failing.
•
70% doing well.

11. Catastrophic failure
•
Fracture
•
Cup Migration/ Spin Out
•
Infection
•
Metal Ion related Inflammatory response:
a.Osteolysis b. Solid or Cystic Pseudotumor c.
Necrosis d. Muscle Disruption

12. preoperative planning
History: Function & Pain.
Examination: Trochanteric tenderness, ROM irritability, Grating?clunking, Psoas &
Abductor Power.
Make Sure it is not infected.
MRI: To know the abnormal tissue locations.

13. Preoperatve Asses
•
Blood: CBC, LFT, ESR, CRP, Check Renal
functions, Exclude Infections.
•
Blood Cobalt & Chromium Levels:
Controversial, Little Science - much opinion,
Changing Goal Post.

14. Blood Metal levels
•
Normal Levels: Agreement poor between labs.
2-7 vs 0-20nMol/L
•
BOA/AOA statements: <40nMol/L OK; 3- 4x cause of concern. toxicity >125nMol/L

15. Preoperative asses
•
Xray: Positioning- Inclination Angle, Lucent
Lines, Osteolysis, H.O
•
MRI: Fluid Collection ( Joint Effusion, “bursal”,
“Cystic Pseudotumor”, Synovial Thickening,
Solid Pseudotumor ( FB Granuloma), Status
Muscles/Tendons, Osteolysis)

16. intra-operative tech
Lots of unappreciated osteolysis - always have
bone available.
Dislocation: downsizing bearing dia, pt used
to hip that does not dislocate, deficient
abductors.
Infection?: Masses of abnormal soft tissues,
careful resection required.
Keep Constraints/ Explant available

17. Infected
Infected
Make Sure it is not

18. Resect all
Abnormal Tissues

19. Cup Extraction

20. Use Explant

21. Have bone graft available

22. Use constraint if necessray

23. Implants usually Normal

24. Post operative
•
Use drains as necessary.
•
Hip Precautions: 3/12 to form pseudocapsule.
•
Expect 90% reduction in Cobalt & Chrome
levels in 3/12

25. Metal ions in body

26. Metal Hypersenstivity

27. Monk forced to sell
ferrari
Text
One of My fellowship Trainers
who had to leave his practice in
Australia and take”sanyas”
”
Every Tragedy has learning points some deeply Personal.

28. Learn to Pick bad eggs
< -Be Wary of ‘miles ahead’ Technology
and
Lawyers
->

29. New surgeons

30. Lessons Learnt!
•
Be Careful!

31. Thank You!
Text
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