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Why I do use uncemented implants. Jean-Luc LERAT Bernard MOYEN (Centre Hospitalier Lyon-Sud) 11èmes Journées Lyonnaises de Chirurgie du genou Oct 2004. Since 30 years surgeons argue about the use of cement for TKA Nevertheless
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Why I do use uncemented implants Jean-Luc LERAT Bernard MOYEN (Centre Hospitalier Lyon-Sud) 11èmes Journées Lyonnaises de Chirurgie du genou Oct 2004
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
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
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
In favourofuncemented TKR ( f.up >10y) Onsten I, Norqvist A, Carlsson AS, Bejaskov J, Shott S. AJ 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
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
Comparative studies : cemented vs uncementedNO 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
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
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!
Coating Polyethylene pegs (Freeman) Hydroxyapatite Porous metal (Hungerford) Micro spheres Titanium mesh (Miller-Galante) CSTi (Sulzer) Polyethylene Calcium Hydroxyapatite Titanium micro spheres Titanium meshCSTI TM
CSTiTM Interface Microstructure CSTi TM (Natural – INNEX) Pores : 4 - 500 microns Cancellous bone Pores : 4 - 500 microns
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 porous+HAC : 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
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
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
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 2001120 TKR survival : 91% 23 yrs Uncemented «LCS New-Jersey» • Buechel FF Sr, Buechel FF Jr, Pappas MJ, D’Alessio 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
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 74 TKR « Insall-Burnstein full Polyethylene » vs 82 TKR « Insall-Burnstein MB ». radio lucent line : 29%: MB , vs 11% full poly, but no clinical difference. Survival rate f.up 11 ys : 92,6 % and 98 %.
Drawbacks of the MB Implant fractures (never with recent TKA)
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
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.up:10 ys Survival rate : 92 % for cemented non modular MB plateaus 90 % for cemented modular MB plateaus 97 % for cemented all poly plateaus
My personnal experience : 4399 arthroplasties Cement : 1408 (THA + TKA) Cementless : 2991 • knee : 1121 • Hip : 1870 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 • 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
Personnal experience of cementless TKR HAP CSTI TM 346 cases 775 cases Natural « Goëland » Survival rate : 94 % f.up : 10 to 16 ys Innex
when the bone cuts are good Cementless shortens the procedure The best cement is spongious bone under the implant before impaction
Revisions are easierin 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
Case of revision of a cementless tibial implant Removal of the implant Rare case of osteolysis under the medial plateau
Case of a cementless tibial implant : osteolysis with progressive subsidence 2-6 months p.o
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 stabilisationin this bad position. Revision to correct flexion contracture Difficulties to separate implants from bone !!
I stil use cemented TKR Constrained TKR for : Important articular damages Ligamentous laxity AXEL
I stil use cemented TKR With non constrained prostheses PCL
I stil use cemented TKR Uncemented femur With non constrained prostheses Revision for a septic case (2 stages) Long stems
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
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
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 ?