1. Acetabular Revision Surgery
The Story of Three Revolutions

2. William H Harris, MD The Alan Gerry Professor of Orthopædic Surgery
Harvard Medical School and Massachusetts General Hospital

9. Three Key Problems in Acetabular Revisions
Fixation
Lysis
Dislocation

10. Revolution 1 Obtaining Fixation Solution
The Harris-Galante design of socket
A hemispherical porous socket, either fixed with screws or press fit

11. That design or its look-a-like is now widely accepted worldwide,and has been copied by nearly every implant manufacturer

12. Additional Unique concepts that we introduced with it
The High Hip Center
The Jumbo Cup

13. Cemented Acetabular Revisions in general did not have a good track record,especially in cases with marked loss of bone stock.

14. MGH Series
From 188 consecutive revisions by one surgeon, 122 had 10 year plus data, average 12.5 years

15. Average age 54 58 High Hip Centers 13 Jumbo cups (65 mm or greater)
Femoral head penetration mm/year

16. Rerevised for ASL 5/ 188 (2.6%) 5/ 122 (4%)
Pelvic lysis (plain films) 9.6%

17. Rush-Presbyterian Series
109 hips at 10.5 years
Kaplan-Meier for 11.5 years 98%
years for revision for any cause plus ASL, not revised
84%

18. Iowa Series 61 hips followed to death or to 13-15 years
Loose or revised for being loose
Pelvic lysis (plain films) 5%

19. Summary 358 Acetabular revisions with 292@ 7-15 years
Rerevised for ASL 5/ (2%)
Pelvic lysis 9%

20. Thus, the first revolution has taken place
Thus, the first revolution has taken place. The fixation issue is solved.

21. Major players in the management of large bone loss in acetabular revision THR are
1) The Jumbo Cup
2) The High Hip Center

22. Advantages of a Jumbo Socket
Large contact area with host bone
Decreased load per unit area at interface
Thick polyethylene
Restores hip center if high and if protrusio

34. Jumbo Cup Series Study Group N= 24 consecutive hips (24 pts)
Shell Diameter ≥ 66 mm (66-74)
Minimum follow-up of 5 years. Average follow up 7 years

35. Results Acetabular Components 0 revisions 0 loose 0 continuous RLL
One with pelvic lysis around screw deceased

36. Cementless sockets require rigid fixation in intimate apposition to intact viable host bone . . . .

37. If the only intact viable host bone is up high
Do a high hip center!

38. Lateral hip centers are bad, but nearly all high hip centers are just high, not lateral

39. Prerequisites for successful high hip center :
Restore leg lengths with long neck or calcar femoral prosthesis
Restore abductor tension by advancing the trochanter
Eliminate any impingement in normal ROM

42. High Hip Center Series Study Group N= 46 consecutive hips (44 pts)
Post-reconstruction hip center ≥ 35 mm above interteardrop line
Minimum follow-up of 8 years

43. Results Acetabular Components No shell revisions One loose shell (4%)
Two with pelvic lysis One around screw One with loose shell

54. Revolution Number 1
Fixation of the component in Acetabular reconstruction in revision surgery is now vastly improved.

55. Impaction grafting is a rare, but helpful operation.
Bulk allografts are now very rare.
Impaction grafting is a rare, but helpful operation.

56. Pelvic discontinuity and extremely massive bone loss cases require other techniques.

57. Cages Not needed very often Can be very valuable
Less successful than the simpler techniques

58. Revolution 2
Eliminating Lysis

59. Ceramic on Ceramic : Advantages
Long duration human use
Low lysis incidence
Relatively inert material

60. Metal on Metal : Advantages
Long duration human use
Low lysis incidence
Relatively inert material

61. Highly Crosslinked Polyethylene : Advantages
Long duration human use
Low lysis incidence
Relatively inert material

62. Highly Crosslinked Polyethylene : Additional Advantages
Cost
Impingement is benign
Tolerates socket malposition
Adaptable
Forgiving
Not brittle
Not produce metalosis
No remote metal deposits

63. 10 year follow-up of the low friction arthroplasty of the hip using alumina-ceramic and crosslinked polyethylene in 14 hips
Wroblewski, Siney, Fleming ‘99

64. After the initial bedding in period, the subsequent calculated annual average wear rate was 20 microns per year
Wroblewski, Siney, Fleming ‘00

65. This later rate was four times less than the rate of wear of stainless steel hips on ultra high molecular weight polyethylene in the contra- lateral hips in 4 of these patients.

66. The initial penetration rate during the first 2 years was 0
The initial penetration rate during the first 2 years was 0.15 mm per year and thereafter was 0.06 mm per year, against a 28-mm chrome cobalt head.
Oonishi & Coworkers ‘98

67. Charnley (1975) No wear No osteolysis Charnley 9yr PO 2mm wear
Pta 4yr PO
No wear
Pta 19yr PO
No wear
Charnley 24yr PO
4.5mm wear
(Ref. C.W.C. 65 Yrs)

68. 85 of the 103 hips had no detectable wear at an average follow-up of 15.5 years.

69. In total, 145 total hip replacements in patients with highly crosslinked polyethylene were followed years. The data on wear are outstanding.

70. Hip Simulator Wear Test Results
2000
1800
Conventional
1600
Polyethylene mm
1400
1200
1000
Total Wear (cubic mm)
22 mm
800
600
400
Cross Linked
200
Polyethylene - 22 mm and 32 mm 5 10 15 20 25 30
Cycles (millions)

71. There is no detectable wear
Gravimetrically - no detectable wear
CMM machine - no detectable wear
Millipore filter the serum - no particles
The machine marks are still present after 30 million cycles

72. Alumina Third Body Particles
E-beam treated and conventional polyethylene liners subjected to 0.15mg/cc Alumina particles continually circulating through test chamber.

74. RSA data available at follow up
Clinical study-RSA
RSA data available at follow up
( )
1 year
crosslink = 27 / control = 29
2 year
crosslink = 19 / control = 24

75. Conclusion control "cross-linked"
On the standing films, there is no change in the superior penetration into the crosslinked polyethylene between 1 and 2 years. Using this interval, the highly crosslinked polyethylene has significantly less penetration, p<0.03.
" ! 6 12 18 24
months
0,05
0,1
0,15 mm
"cross-linked"
control

76. Revolution 3
Eliminating Dislocation
Solution The Big Head

78. Because E-beam highly crosslinked poly has such low wear and particularly because wear is independent of head size, the issue of dislocation can be addressed directly with larger head sizes.

79. Amstutz has shown the marked advantages of using large head diameters in cases of recurrent dislocation or high risk for recurrent dislocation

80. Consider the advantages of larger femoral head sizes in terms of:
ROM
Impingement
Stability
ADL
Dislocation rate

81. Recall that Charnley’s first THR had a head size of 41.5 mm
The plastics available to him 50 years ago could not withstand that head size
He was forced to drop down progressively until he settled on mm

83. Type of Impingement 28mm Femoral Head Versys®Stem Natural®Stem 0º 15º
Anteversion
Versys®Stem
Natural®Stem 0º
15º
This slide appears complex, but is actually simple.
Component impingement is shown in red.
Component - Bone impingement is yellow
Pure bony impingement is tan.
The versys stem data is in the left-hand column, and the natural stem data is listed on the right.
Look what happens when you go from the 28 head,
30º
Component on Component
Component on Bone
Bone on Bone

84. Type of Impingement 38mm Femoral Head Versys®Stem Natural®Stem 0º 15º
Anteversion
Versys®Stem
Natural®Stem 0º
15º
TO the 38 and ...
30º
Component on Component
Component on Bone
Bone on Bone

85. Large heads eliminate component-component contact .
Only limit to ROM is patient’s bony anatomy .
Because large heads virtually eliminate component impingement, the only limit to the available range of motion is the patient’s bony anatomy.

87. In Short
Acetabular revision surgery has seen one Revolution and two more are immediately available

88. We have solved the fixation problem, using the hemispherical porous socket fixed with pressfit or screws.

89. Probable Revolution # 2
It is highly likely that we have made a major advance in the lysis issue by the electron-beam irradiated, highly crosslinked, melted UHMWP.

90. Probable Revolution # 3
Because with E-beam highly crosslinked poly, wear is independent of head diameter,we can attack the dislocation problem directly using much larger heads.

91. Thank You