Why I do use uncemented implants

1
Why I do use uncemented implants

• Jean-Luc LERAT
• Bernard MOYEN
• (Centre Hospitalier Lyon-Sud)
• 11èmes Journées Lyonnaises de Chirurgie du genou
• Oct 2004

2

• Since 30 years surgeons argue about the use of
  cement for TKA
• Nevertheless
• Surgeons  cement non user  may appreciate to
  use cement in special occasions
• Many surgeons use a hybrid TKR with uncemented
  femoral implant

3
Historical

• First uncemented prostheses 1970 (diffusion
  after1980)
• After some years, literature pointed out
  complications related to implant designs, poly
  wear, osteolysis, metallic debris.
• Cuckler JM et al. Clin Orthop 2003
• Noble PC, Clin Orthop 2003
• Reilly MA, Walker PS et al. Clin Orthop 1982
• Wasielewski et al. Clin Orthop 1997
• Gill GS et al. Clin Orthop 1999 and J Bone Joint
  Surg 2001
• Laskin RS. Clin Orthop 2001
• Pavone V et al. Clin Orthop 2001
• Callaghan et al. J Bone Joint Surg 2000

4
Cement vs cementless

• CEMENT, negative points
• Difficult to do a good cementation
• Operative time increased
• Microembolisms possible
• Polymerization heating may lead to bone necrosis
• Possible allergy
• 2 additional layers
• Difficult to remove the excessive cement in the
  back of the knee
• Cement debris can be included into poly
• Frequent lucent line under the cemented plateaus
• Bony stock decreased
• Revisions more difficult

• CEMENT, negative points
• Difficult to do a good cementation
• Operative time increased
• Microembolisms possible
• Polymerization heating may lead to bone necrosis
• Possible allergy
• 2 additional interfaces
• Difficult to remove the excessive cement in the
  back of the knee
• Cement debris can be included into poly
• Frequent lucent line under the cemented plateaus
• Bony stock decreased
• Revisions more difficult
• CEMENTLESS, negative points
• Stability is mandatory for bony integration
• Difficult to obtain a good bioactive surface
• Shear and tension on uncemented tibial implant
• Uncemented TKR are more expensive !
• Metal-back is necessary

5
In favour of uncemented TKR ( f.up gt10y)

• Onsten I, Norqvist A, Carlsson AS, Bejaskov J,
  Shott S. A J Bone Joint Surg 1998 
• Hydroxyapatite augmentation of the porous
  coating improves fixation of tibial component a
• randomised RSA study in 116 patients
• Witheside LA. Clin Orthop 2001
• Long-term followup of the bone-ingrowth Ortholoc
  Knee System without a metal-backed patella
• Hofmann AA. Hofmann AA, Evanich JD, Ferguson RP.
  Clin Orthop 2001
• Ten to 14-year clinical followup of the
  cementless Natural Knee
• 300 TKR 10 yrs survival 95.1
• Dixon P, Parish EN, Chan B, Chitnavis J, MJ
  Cross. J Bone Joint Surg 2003
• Hydrxyapatite-coated, cementles total knee
  replacement in patients aged 75 years and over

6
Comparative studies cemented vs uncemented
in favour of cemented implants

• Lachiewicz PF. Cement versus cementless
  total knee replacement  is there a place for
  cementless fixation in 2001.Current opinion in
  orthopaedics 2000
• RSA study bony fixation more secure with
  cement. Some cementless design have good results.
  
• The main drawback uncemented implants are
  too expensive!
• McCaskie AW et al. Randomised, prospective
  study comparing cemented and cementless total
  knee replacement. Results of press-fit condylar
  knee replacement at five years, J Bone Joint Surg
  1998 
• Prospective randomised study on 139 TKR. At
  5 years f.up frequent lucent lines with cement.
• BUT uncemented implant are too expensive!
• Duffy GP et al. Cement versus cementless
  fixation in total knee arthroplasty. Clin Orthop
  1998 
• Prospective study of 55 Press fit condylar
  (PFC) vs 51cemented PFC .
• More revision in the uncemented group
  (patellar problems).Survival rate10 ys 72 vs
  94
• Berger RA et al. Long term followup of the
  Miller-Galante total knee replacement. Clin
  Orthop 2001
• 172 cemented TKR  Miller-Galante I  vs
  109  Miller-Galante II  f.up 11ys.
• Survival rate 84 for MG I and 100 for MG
  II. Difference due to patellar problems of the
  MGI

Several studies confirm these data concerning
patellar implant
7
Comparative studies cemented vs uncemented
NO difference

• Khaw FM et al. A randomised controlled
  trial of cemented vs cementless press-fit
  condylar total knee replacement. Ten year
  survival analysis.
• J Bone Joint Surg 2002
• 277 cemented PFC vs 224 cementless
  survival rate 96,5 - 96,6 f.up 10 ys.
• Bassett RW. Results of 1000 performance
  knees cementless versus cemented fixation.
• J Arthroplasty 1998
• 584 cementless vs 416 cemented TKR f.up 5
  ys (survival rate 99) NO difference
• Buechel FF et al. Twenty-year evaluation
  of meniscal bearing and rotating platform knee
  replacements. Clin Orthop 2001
• 373 LCS New Jersey (64 cemented, 104
  cementless porocoat CR, 109 rotating). Survival
  rate 97,7 f.up 10 yrs and 20 yrs. NO
  difference for bony fixation.
• Parker DA et al. Long-term followup of
  cementless versus hybrid fixation for total knee
  arthroplasty. Clin Orthop 2001
• 100 Miller-Galante I, with or without
  cement NO difference after 12.8 ys

8
Still it is difficult to compare different TKR

• Shape, design are different
• Fixation
• 1, 2, 3 or 4 pegs
• Cross shaped stem, short, long
• Cylindric stem, smooth or not

9
The mechanical behaviour is variable according to
the implant designs

• Walker PS et al. J Bone Joint Surg 1981
• Study of 12 cemented tibial implants on cadaveric
  tibias
• The best fixations were obtained with
• - Full poly plateau
• - Monobloc metal-backed implant (with one
  or two pegs)

With cementless implants, a cadaveric
experiment is obviously Impossible!
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Coating
Polyethylene pegs (Freeman) Hydroxyapatite
Porous metal (Hungerford) Micro spheres
Titanium mesh (Miller-Galante) CSTi (Sulzer)
Polyethylene Calcium
Hydroxyapatite Titanium micro spheres
Titanium mesh CSTI TM
11
CSTiTM Interface Microstructure
CSTi TM (Natural INNEX) Pores 4 - 500
microns
Cancellous bone Pores 4 - 500 microns
12

• RSA studies implant osteointegration and
  stability
• - Fuiko Ret al. Osteointegration and
  implant position after cementless total knee
  replacement. Clin Orthop 2003
• 101 uncemented LCS New Jersey
• - Onsten I et al. A Hydroxyapatite
  augmentation of the porous coating improves
  fixation of tibial component a randomised RSA
  study in 116 patients. J Bone Joint Surg 1998
• 146  Press fit condylar  (PFC) 49
  cemented, 47 with porous coating and 50
  porousHAC No difference
• - Hofmann AA et al. 10 to 14-year clinical
  followup of the cementless Natural Knee System.
• Clin Orthop 2001s
• 176 Natural Knee with CSTI survival rate
  of 95 , f.up 10 ys.
• Witheside LA. Long-term followup of the
  bone-ingrowth Ortholoc Knee System without a
  metal-backed patella. Clin Orthop 2001
• 202  Ortholoc porous coated  survival
  rate of 98.6 f.up 18 ys
•  

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Osteo integration of cementless implants A
Reality ! Stable with time !

• Stability is quickly obtained
• - if the bony cuts are correctly done
• - if implants are in contact with the spongious
  bone
• - and covering cortical bone
• The post op rehabilitation is the same in the 2
  groups
• Cemented or cementless

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Fixation - osteointegration - wear

• Femur In the literature femoral
  osteointegration is not a problem.
• Tibial fixation is more controversial
• Osteolysis had been described (could be related
  to poly wear debris)
• But osteointegration is successfull
• Loosening should not be confused with fixation
  failure !

• The results depend on many factors
• Age
• Weight
• Osteoporosis
• PCL Conservation or not
• Patellar resurfacing or not
• Polyethylene thickness
• Quality of poly fixation on the tibial implant

15
2 TKR are considered as gold standard each in
its own categorie

• Cemented Total condylar
• Brassard MF, Insall JN et al. Clin Orthop 2001
• Gill GS et al. Clin Orthop 1999. J Bone Joint
  Surg 2001
• Rodriguez JA, Bhende H, Ranawat C. Clin Orthop
  2001
• Pavone et al Clin Orthop 2001 120 TKR
  survival 91 23 yrs
• Uncemented LCS New-Jersey
• Buechel FF Sr, Buechel FF Jr, Pappas MJ,
  DAlessio J. Twenty-year evaluation of meniscal
  bearing and rotating platform knee replacements.
  Clin Orthop 2001
• Similar survival rate
• BUT tibial plateaus are different
• -  all poly  for Total condylar
• - Rotatory metal-backed for LCS

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Cement and  metal backed  (MB) tibia

• In favour of cemented MB
• Gill GS, Joshi HB. Long-term results of Kinematic
  condylar knee replacement
• 404  Kinematic  cemented CR . Survival rate
  92.6 f.up 17 ys
• Laskin RS. The Genesis Total knee
  System. A 10-year followup study. Clin Orthop
  388, 95-102 2001
• 100 TKR cemented Genesis  Survival
  rate 97 f.up 10 ys ( with or without PCL)
• Lachiewicz PF. Cement versus cementless total
  knee replacement  is there a place for
  cementless
• fixation in 2001. Current opinion in
  orthopaedics 2001
• In favour of cemented full poly
• Rodriguez JA et al Total Condylar Knee
  Replacement. A 20-year followup study. Clin
• Orthop 2001
• Brassard MF, Insall JN et al. Does modularity
  affect clinical success? A comparison with a
• minimum 10-year followup. Clin Orthop 2001 388
  26-32

17
Drawbacks of the MB Implant fractures (never
with recent TKA)
18
Drawbacks of the MB Polyethylene wear

• Noble et al. Clin Orthop 2003
• Wear cemented TKR 35 , non cemented TKR 25
  .
• Impingements with cement fragments
• Cuckler et al. Polyethylene damage on the
  nonarticular surface of modular total knee
  prostheses. Clin Orthop 2003
• Polyethylene can be wear out along the non
  articular tibial surface with modular
• plateaus
• Reilly, Walker et al . Effects of tibial
  component on load transfer in the upper tibia.
  Clin Orthop 1982

19
Studies proving the best behaviour of moulded or
fixed poly plateaus

• Meding et al. Clin Orthop 2001
• 387 cemented TKR  AGC  Survival rate
  94.3 f.up 10.7ys
• Comparison moulded 4.4 mm poly plateau on a
  3.6 mm metallic plateau vs 10mm all poly plateau
  NO difference.
• Ritter MA et al. Clin Orthop 2001
• 4583 TKR cemented  AGC  (except 348
  cemented femurs) with PCL and a moulded poly
  plateau on metal survival rate 98.8 at 15 ys.
• Rand JA et al. J Bone Joint Surg 2003.
• F.up10 ys Survival rate 92 for cemented
  non modular MB plateaus
• 90
  for cemented modular MB plateaus
• 97
  for cemented all poly plateaus

20
My personnal experience 4399 arthroplasties

• uncemented knees (out of 1572)
• I almost never use cement for primary TKR
• I only use cement
• - In case of hinge TKR
• - For some revisions
• - In case of large bony defects when a
  bone graft
• could delay the weight bearing

For my last 500 consecutive TKR, cement has still
been used - for 17 femurs (
3.1 ) - for 70 tibias ( 15 )
Other features of the series 480 knees
are CR (PCL) (96 ) Only 4 of patella
resurfaced

• Cement 1408 (THA TKA)
• Cementless 2991
• knee 1121
• Hip 1870

21
Personnal experience of cementless TKR
HAP
CSTI TM
346 cases
775 cases
Natural
 Goëland 
Survival rate 94 f.up 10 to 16 ys
Innex
22

• Cementless shortens the procedure

when the bone cuts are good
The best cement is spongious bone under the
implant before impaction
23
Revisions are easier in cementless cases

• The use of thin chisels can separate the implant
  from the bone, step by step, with a minimum
  damage to the adjacent bone
• It is not the case after cementation !

Preservation of the bone stock is an important
issue for the future

• A new cementless implant is often still
  possible
• Or a cemented implant, but the use of standard
  TKR, as in primary
• cases, is possible

24
Case of revision of a cementless tibial implant
Removal of the implant
Rare case of osteolysis under the medial plateau
25
Explanted knees shown a good bony ingrowth
CSTI
26
Case of a cementless tibial implant osteolysis
with progressive subsidence 2-6 months p.o
27

• Uncemented bio active surfaces are able to create
  an osteointegration even lately
• After subsidence the uncemented implants can
  found a new and stable position
• In case of cemented TKR loosening is the
  only answer
• Hofmann AA et al. Ten to 14-year clinical
  followup of the cementless
• Natural Knee System. Clin Orthop 2001

Tilting, then stabilisation in this bad
position. Revision to correct flexion
contracture Difficulties to separate implants
from bone !!
28
I stil use cemented TKR
Constrained TKR for Important articular
damages Ligamentous laxity
AXEL
29
I stil use cemented TKR
With non constrained prostheses
PCL
30
I stil use cemented TKR
Uncemented femur
With non constrained prostheses
Revision for a septic case (2 stages)
Long stems
31
But revisions are possible with cementless TKR
500 recent primary TKR during the same time 66
TKR were revised 21 uncemented femurs
24 uncemented tibias
32
Advantages to use uncemented TKR

• Uncemented femoral implant no problem
• Uncemented tibial implant metal backed 
• Good osteointegration
• Bone stock preservation
• Revisions are easier
• Metal back have many advantages
• Modularity with a polyethylene plateau that can
  be changed without removing the tibial implant
• The poly wear is similar to the full poly plateau
  if it is thick enough and well fixed
• The possible use of a mobile bearing

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ConclusionWhy do I use uncementd TKR ?

• In primary cases, cementless or cemented TKA are
  similar

Cement is usefull when the bony conditions are
poor
The question is rather Why should I use cement
when it is not necessary ?