Accelerated Failure of the ASR XL at North Tees

Tony Nargol ,

R Sidaginamale, PKR Mereddy, JN Gandhi, T Joyce DJ Langton, R Logishetty,

University Hospital of North TeesUK

Prospective study:2004 – 2008 n= 505

ASR resurfacing

N = 418

ASR XL (THR)

N = 87

Failures due to bearing surface wear

Failures due Taper failure of ASR THR

Failure due to ARMD of ASR & ASR xl

ASR THR 50% failure at 75 months

ASR resurfacing

North Tees JBJS Br August 2011

In response to our paper in same August JBJS

Prof fisher Prof Learmonth

Surgical error !

So what is the evidence ?

Failures by cup size ASR v ASR xl

44 46 48 50 52 54 56 58 60 62 640

10

20

30

40

50

60

70

80

90

100

ASRASR XL

% failures

Cup size

1. Comparison of ASR with BHR

Tony Nargol single series

The Incidence of Adverse Reactions to Metallic Debris(ARMED) with two

Resurfacing devices

AVF Nargol DJ Langton, SS Jameson, T Joyce

American academy (AAOS) 2010

University Hospital of North Tees, Stockton-on-Tees,UK

School of Mechanical & Systems Engineering, Newcastle University

Results ASR v BHRASR BHR ASR THR

No of patients

Mean F/U 3.8 yrs 5.2 yrs 4.5 yrs

ARMD Females

ARMD Males

ARMD Total

ARMD Rate 5.9 % 0 % 11.4 %

Cup position error ?

What was Depuy advice or warning on cup position ?

Whole Blood Metal Ion Levels and Component Positioning after Surface Replacement of the Hip: Early Results

American Hip and Knee and knee Society (AHKS)3rd Nov 2007

GH Isaac A Cobb

R McLennan-SmithR OakeshottT O’Sullivan

T SiebelT Schmalzried

TP Vail

UK, S Africa, Australia, Germany, USA

Metal Ion Data, Effect of Implant InclinationConsecutive patients, 4 centres, N= 50(24m)

24m Ion Level v Inclination Group

2.3

12.6

2.5

24.1

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

35-55 (42) 55+ (8)

Inclination Group (deg)

Ion

Le

ve

l (u

g/l

) Cr (ug/l)

Co (ug/l)

....... a standard cup angle (<55 degrees )

Recommended cup positions for resurfacing

• Depuy inclination up to 55 degrees (AAHKS 2007)

• Oxford : Safer zone (JBJS 92B )– 35-55 inclination– 10-30 anteversion

Failure numbers ASR and ASR xl by cup inclination Tony Nargol (TN)

< 35 35-40 40-45 45-50 50-55 55-60 >600

5

10

15

20

25

30

ASR & ASR xl

Cup inclination

No of cases

Failure numbers ASR and ASR xl by cup inclinationTony Nargol

< 35 35-40 40-45 45-50 50-55 55-60 >600

5

10

15

20

25

30

ASR & ASR xl

Cup inclination

No of cases

Number of failures below and above 55 cup inclination

greater than 55

less than 55

-80 -60 -40 -20 0 20 40

Number of failures below and above 55 cup inclination

greater than 55

less than 55

-80 -60 -40 -20 0 20 40

72 cases

Tony Nargol (TN) all ASR CUP POSITIONS

all >20070

10

20

30

40

50

60

70

45.740.7

INCLINATION

Mean cup inclination

25th-75th centiles

spread

TN all ASR cup position compared to other centres

all TN TN >2007 Hart Wrightington Oxford Treacy 0

10

20

30

40

50

60

70

80

45.740.7

49 5046.6

49

INCLINATION

ASR xl failures inclination & anteversion

20 25 30 35 40 45 50 55 60 650

10

20

30

40

50

Anteversion

inclination

ASR xl failures inclination & anteversion

20 25 30 35 40 45 50 55 60 650

10

20

30

40

50

Anteversion

inclination

18 failures inside zone 11 failures outside zone

ASR xl failures inclination & anteversion

20 25 30 35 40 45 50 55 60 650

10

20

30

40

50

Anteversion

inclination

18 failures inside zone 11 failures outside zone

Depuy 2010 target

ARMD failure of ASR

Inclination 44.4*

ARMD failure of ASR

45.0*

ARMD failure of ASR

41.5*

ARMD failure of ASR

41 *

ARMD failure of ASR

42 *

ARMD failure of ASR THR

40 *

ASR Xl mean cup inclinations

Failed

46.7 degrees

(NS difference)

non-failed

46.5 degrees

Other centres failure of ASR XL

• S Jones (Cardiff)• D Beverland• York• Norfolk & Norwich

Conclusion

• ASR Xl failing at 50% at 7 yrs • Majority are in safe zone

• Taper failure has no relationship to cup position

UK National joint registry for ASR XL

• 2010 5yr 12% failure of ASR XL

• 2011 6yr ? Double to 24%

• 2012 7r ?? Double again 50%

Message to Depuy

I implanted 87 ASR xl so I am not influencing the NJR figures