Special Focus Section
193
Cementless Total Knee Arthroplasty: A Review Jeffrey J. Cherian, DO1 Samik Banerjee, MS (Orth), MRCS (Glasg)1 Bhaveen H. Kapadia, MD1 Julio J. Jauregui, MD1 Steven F. Harwin, MD2 Michael A. Mont, MD1 1 Center for Joint Preservation and Replacement, Rubin Institute for
Advanced Orthopedics, Baltimore, Maryland 2 Department of Orthopaedic Surgery, Beth Israel Medical Center, New York, New York
Address for correspondence Michael A. Mont, MD, Center for Joint Preservation and Replacement, Rubin Institute for Advanced Orthopedics, 2401 West Belvedere Avenue, Baltimore, MD 21215 (e-mail: [email protected]).
Abstract
Keywords
► cementless total knee ► noncemented ► total knee arthroplasty ► implant
There is ongoing debate over the use of cementless fixation in total knee arthroplasty (TKA). Previous generation prostheses resulted in less than optimal outcomes which was somewhat attributed to design issues. As the demand for TKA is continuously increasing and the current U.S. age population is getting younger, cemented fixation may not provide adequate long-term outcomes due to failure of fixation. Thus, there has been a reemergence of the development and use of cementless TKA. Recent short-term trials have demonstrated that modern cementless TKA has comparable survivorship and functional outcomes as cemented prostheses. However, more prospective, randomized trials are needed to clearly delineate any differences between these two fixation options.
Over the past decade, cemented total knee arthroplasty (TKA) has demonstrated excellent clinical outcomes as well as implant survivorship.1 The use of cementless fixation has been available for the past three decades,2,3 but due to less than optimal outcomes with previous generation prostheses, this fixation method never gained popularity.4 Nevertheless, as the indication and numbers of TKA continue to increase, younger and more active patients are undergoing the procedure.5 Therefore, the long-term durability of cemented fixation has come into question in these high-demand patients, because cement has shown to have a poor resistance to shear and tension forces which may result in deformation and degradation over time.6,7 In addition, studies have noted that young and active patients have a higher rate of longterm loosening due to osteolysis present at the cement–bone interface. Recently, cementless TKAs have made a reemergence with newer designs, and manufacturing techniques.8 Studies demonstrated the importance of bone ingrowth that might lead to more long-term implant stability and durability of fixation.9,10 The purpose of this report is to summarize the recent evidence on cementless TKA. This review will specifically focus on the following: (1) History and technology; (2)
received February 19, 2014 accepted March 16, 2014 published online April 24, 2014
Survivorship; (3) Functional outcomes; (4) Economics; and (5) The future outlook of these prostheses.
History and Technology Cementless TKA has been around for more than three decades, but as previously mentioned, due to complications and less than optimal outcomes with first generation prostheses, these implants did not gain favor over their cemented counterparts. They were originally created to improve the longevity of the implants, especially in young and active patients. It is believed that an implant with a more physiological bond between the bone and implant can result in improved survival from aseptic loosening, due to the ability of its interface to respond to stresses in a physiological manner.11 However, the reluctance of cementless use in TKA may have originated from issues developing from screw track osteolysis, poor early polyethylenes, metal-backed patellar failure, and the lack of several press-fit designs failing to demonstrate clinical superiority over cemented implants.5 Another reason for implant failure was the subsidence and failure of the cementless tibial trays, which were originally implanted in cancellous bone instead of upon the cortical rim.12 In
Copyright © 2014 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662.
DOI http://dx.doi.org/ 10.1055/s-0034-1374811. ISSN 1538-8506.
Downloaded by: Washington University. Copyrighted material.
J Knee Surg 2014;27:193–198.
Cementless Total Knee Arthroplasty
Cherian et al.
addition, cementless fixation may be more sensitive to malalignment, especially in relation to the tibial component. This may be because sheer forces applied by varus or valgus tibial base plate positioning can alter the distribution of compressive forces across the implant–bone interface resulting in excessive point loading.13 The recent use of bioactive coating that is sprayed onto the surface of the implant may optimize bony ingrowth.14–16 It is thought that hydroxyapatite coatings act by providing additional anchorage across any motion-induced fibrous membranes between the implant and the bony surface.17 Similarly, newer designs are composed of newer trabecular metals which have been demonstrated to have similar elastic characteristics as bone, and a high level of porosity makes it a favorable environment for bony ingrowth.18 Both of these types of implant designs have been shown on radiostereographic analysis studies that these lead to decreased micromotion compared with traditional press-fit designs and cemented prostheses.19 These fixation characteristics may ultimately predict less risk of late aseptic loosening.
Outcomes of Early Designs Many clinical trials on earlier generation, cementless knee implants have demonstrated that cementless TKA led to poor survivorship outcomes.20–23 A study by Berger et al20 evaluated the long-term survivorship in a series of 131 patients (131 knees) who underwent cementless TKA with a Miller Galante I system (Zimmer Inc, Warsaw, IN). The authors found that there was 8% rate of ingrowth failure, and partial radiolucencies in 53% of the tibias. In addition, they noted that there was a 12% incidence of osteolysis around screw holes at mean follow-up of 11 years. Similarly, Duffy et al,21 in a comparative study, reported on the survivorship of cemented (n ¼ 51) versus noncemented (n ¼ 55) press-fit condylar TKAs at 10-year follow-up. The authors found that there was substantially lower 10-year survivorship in the noncemented group (87.6%) compared with cemented (96.1%) cohort. Exclusive on elevation of problems related to the metal-backed patellar, survival to revision for aseptic failure, or radiographic loosening was higher in the uncemented than the cemented group at 10 years (72 vs. 94%). A meta-analysis by Gandhi et al24 evaluated the survivorship of cemented and cementless TKA in 11 studies (5 randomized controlled trials and 10 observational studies). The authors reported that the odds ratio (OR) for failure of the implant due to aseptic loosening for the uncemented cohort was 4.2 (p < 0.0001) and the cumulative data from the 15 studies revealed a more favorable outcome for cemented fixation. However, when isolated evaluation of the five randomized control trials was performed the authors were unable to demonstrate differences in survivorship between the two cohorts. The authors attributed the higher failure rates of cementless prostheses in observational studies to younger age and increased activity levels of the patient populations who had undergone cementless TKAs. Interestingly, even though a variety of implants were analyzed, none were hydroxyapatite coated. The Journal of Knee Surgery
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However, there were some prosthesis that were able to achieve successful long-term survivorship and outcomes.9,10,25,26 A study by Whiteside10 evaluated the survivorship of 129 patients (163 Ortholoc I; Wright Medical Technology, Arlington, TN) who underwent TKA with cementless tibial and femoral components at 9 to 11 years of follow-up. The authors observed loosening in only one knee during the follow-up period that required revision surgery. Considering all modes of failure, survival rate at 10 years was 94%. In addition, 10 years after surgery, 83.7% of patients had no pain at final follow-up. Thus, there is conflicting evidence concerning the use cementless TKA from historical reports. Nevertheless, more recent studies have reported comparable long-term survivorship and clinical outcomes between cementless and cemented TKA, and these results may be attributed to the newer generation of cementless surfaces and highly porous metals.
Outcomes of Newer Designs Despite the first generation clinical trials that demonstrated that selected cementless TKA led to poor survivorship, more recent designs have comparable outcomes to those of cemented prostheses. A recent systemic review and meta-analysis by Mont et al12 examined 37 studies (3,568 TKAs in 2,940 patients) comparing cementless to cemented TKA. The authors found that cementless TKA had implant survivorship comparable to cemented TKA (OR, 1.1). The mean survivorships were 95.6 and 95.3% for cementless and cemented TKA, respectively at 10-year follow-up. At 20-year follow-up, the authors demonstrated that implant survivorship decreased to 76 and 71% for cemented and cementless, respectively. In addition, they analyzed the use of screw fixation to implant survivorship, and found that no differences were observed between fixation with or without screws (relative risk [RR], 1.1). However, the authors did not differentiate between which implant designs were used. Another systematic review study by Voigt and Mosier27 evaluated implant durability using radiostereographic analysis in three groups of patients (hydroxyapatite [HA] coated, porous coated, and cemented). This study consisted of 926 primary TKAs from 14 studies. The authors noted that HA-coated tibial components without screw fixation were less likely to be unstable at 2 years than porous and cemented tibial components (RR ¼ 0.58, p ¼ 0.04). In addition, there were no significant differences in revision rates at 2 and 8 to 10 years of follow-up, between the groups. A prospective randomized trial of 145 TKAs by FernandezFairen et al28 compared the use of trabecular metal TKA to those performed with cemented implants. The authors found that at 5-year follow-up, the mean Knee Society scores (KSS) was 90.4 (range, 68–100) for trabecular metal cohort, and 86.5 (range, 56–99) for cemented cohort (p ¼ 0.02). In addition, they reported that the mean Western Ontario and McMaster Universities osteoarthritis index (WOMAC) score was 15.1 (range, 0–51) for patients who had received the trabecular metal prosthesis, and 19.1 (range, 4–61) for those who had cemented TKAs (p ¼ 0.02).
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Harwin et al30 on the use of cementless posterior stabilizing knee arthroplasty has demonstrated excellent short-term results that contradict this notion. In this prospective series of 110 patient (114 knees), the authors reported that at a mean follow-up of 36 months (range, 24–50 months), all patients demonstrated to have stable biological fixation with no evidence of loosening, stress shielding, or progressive radiolucencies.30 Given the positive results reported with the newer generation prostheses, we believe that cementless TKAs are comparable alternatives to cemented TKAs in terms of survivorship and clinical outcomes. Please refer to ►Table 1 for a brief summary of reviewed studies.
Economic Perspective With recent health care policy changes and concerns of related costs, implant effectiveness has become an important topic of discussion. Components of cementless TKA have been estimated to cost up to three times more than cemented prostheses.31 Although the direct cost associated with the prosthesis may be higher than their cemented counterparts, the cost per procedure has been shown to be lower with cementless designs.12 This is due to the need for fewer supplies in the operating room.32 Kamath et al32 found that
Table 1 Summary of cementless TKA studies Study, year
Number of knees
Mean follow-up (y)
Brief summary of results
Duffy et al, 199821
102
10
Patients who underwent cementless TKA had lower survivorship than cemented counterpart
Gandhi et al, 200924
–
–
Patient who underwent cementless TKA had higher OR for failure of the implant due to aseptic loosening (OR ¼ 4.2)
Whiteside, 199410
163
10
The authors found that there was a 96.3% survivorship with the use of cementless TKA
Berger et al, 200120
131
11
Early tibial design had an 8% rate of ingrowth failure, and partial radiolucencies in 53% of their tibias
Mont et al, 201312
3,568
10 and 20
Cementless TKA had implant survivorship comparable to cemented TKA (OR, 1.1; 95.6 vs. 95.3%) at 10-year follow-up; at 20 year follow-up, survivorship decreased to 76 and 71% for cemented and cementless, respectively
Voigt and Mosier, 201127
926
2 and 8
HA-coated tibial components without screw fixation were less likely to be unstable at 2 years than porous and cemented tibial components (RR ¼ 0.58, p ¼ 0.04)
Fernandez-Fairen et al, 201328
145
5
Patients in the trabecular metal cementless cohort had significantly higher KSS and WOMAC scores than cemented counterpart
Kim et al, 20141
160
17
Cemented tibial component survival rate was 100%, and the cementless tibial component 98.7%; no significant differences were seen between cementless and cemented total knee arthroplasty in mean KSS, WOMAC index, and ROM
Harwin et al, 201330
114
3
Cementless posterior stabilizing knee arthroplasty at latest follow-up had no radiographic evidence of loosening or stress shielding and all implants had stable biologic fixation
Abbreviations: HA, hydroxyapatite; KSS, Knee Society score; OR, odds ratio; ROM, range of motion; RR, relative risk; TKA, total knee arthroplasty; WOMAC, Western Ontario and McMaster Universities osteoarthritis index. The Journal of Knee Surgery
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A recently published prospective randomized trial by Kim et al1 examined patient satisfaction, long-term clinical, and implant survivorship rates in 80 patients (160 knees) younger than 55 years (mean age, 54.3 years) who had underwent bilateral, sequential, simultaneous TKAs where one knee received a cemented prostheses, and the other was trabecular metal cementless implant (NexGen CR; Zimmer, Warsaw, IN). The authors found that patients described comparable satisfaction 8.1 points for cementless compared with 8.3 points for cemented. On analysis of component survivorship, the authors reported that the femoral component had a 100% survival rate in both the groups at 17-year follow-up. The cemented tibial component survival rate was 100% and the cementless tibial component 98.7% at 17-year follow-up, with no incidence osteolysis being identified in either group. Also, authors noted that there were no significant differences between cementless and cemented TKA in mean KSS (95.8 vs. 96.9), WOMAC (25.4 vs. 25.9), and range of motion (125 vs. 128 degrees). Furthermore, historically the use of posterior stabilizing designs in cementless knee arthroplasty was controversial, due to the unpredictable results from stresses placed on the tibial interface from the cam/postinteraction.29 This interaction was thought to potentially cause micromotion prohibiting biologic fixation, however, a recent landmark study by
Cherian et al.
Cementless Total Knee Arthroplasty
Cherian et al.
at their institution the use of cementless prosthesis cost approximately $596 more than its cemented counterpart. However, after deduction of the cement, operating time, and mixing equipment, there was only a $150 cost difference. In addition, cementless TKA offers the potential advantage of being a shorter procedure with decreased tourniquet times, thus further reducing overall operating costs. One might note that, cement may potentially have the added cost benefit of allowing the delivery of antibiotics directly into the joint, potentially reducing the risk of periprosthetic infections in the population, which may need to be considered when weighting cost benefit analysis of these prostheses.
7
8
9
10
11
Future Outlook The recent generations of cementless TKAs may have survivorship and functional outcomes comparable to those of cemented prostheses. Radiostereographic studies have shown that the new generation of implants with hydroxyapatite bioactive coatings or those made from highly porous metals have superior fixation compared with those without these material properties. We believe these technologies have made the use of press-fits stems a viable option for TKA in the young population. Cost analyses studies are required to assess whether the use should be routine in TKA.
12
13
14
15 16
Conclusion Cementless TKA is a potential fixation option for patients with end-stage knee osteoarthritis, however, multiple prior studies of historically made prostheses raised questions regarding the longevity of these implants compared with the current standard cemented TKA. Recent studies have shown that modern cementless TKA appears to have similar outcomes as compared with cemented total knees at equivalent lengths of follow-up. More prospective, randomized trials are needed to clearly delineate any differences between these two fixation options given the discrepancy in survivorship that has previously been reported.
17
18
19
20
21 22
References 1 Kim YH, Park JW, Lim HM, Park ES. Cementless and cemented total
2
3 4 5
6
knee arthroplasty in patients younger than fifty five years. Which is better? Int Orthop 2014;38(2):297–303 Freeman MA, McLeod HC, Levai JP. Cementless fixation of prosthetic components in total arthroplasty of the knee and hip. Clin Orthop Relat Res 1983;(176):88–94 Freeman MA, Tennant R. The scientific basis of cement versus cementless fixation. Clin Orthop Relat Res 1992;(276):19–25 Silverton CD. Cemented and cementless fixation: results and techniques. Instr Course Lect 2006;55:429–437 Meneghini RM, Hanssen AD. Cementless fixation in total knee arthroplasty: past, present, and future. J Knee Surg 2008;21(4): 307–314 Efe T, Figiel J, Danek S, Tibesku CO, Paletta JR, Skwara A. Initial stability of tibial components in primary knee arthroplasty. A
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23
24
25
26
cadaver study comparing cemented and cementless fixation techniques. Acta Orthop Belg 2011;77(3):320–328 McCaskie AW, Deehan DJ, Green TP, et al. Randomised, prospective study comparing cemented and cementless total knee replacement: results of press-fit condylar total knee replacement at five years. J Bone Joint Surg Br 1998;80(6):971–975 Azboy I, Demirtaş A, Bulut M, Oztürkmen Y, Sükür E, Caniklioğlu M. Long-term results of porous-coated cementless total knee arthroplasty with screw fixation. Acta Orthop Traumatol Turc 2013;47(5):347–353 Hofmann AA, Evanich JD, Ferguson RP, Camargo MP. Ten- to 14year clinical followup of the cementless Natural Knee system. Clin Orthop Relat Res 2001;(388):85–94 Whiteside LA. Cementless total knee replacement. Nine- to 11year results and 10-year survivorship analysis. Clin Orthop Relat Res 1994;(309):185–192 Brown TE, Harper BL, Bjorgul K. Comparison of cemented and uncemented fixation in total knee arthroplasty. Orthopedics 2013; 36(5):380–387 Mont MA, Pivec R, Issa K, Kapadia BH, Maheshwari A, Harwin SF. Long-term implant survivorship of cementless total knee arthroplasty: a systematic review of the literature and meta-analysis. J Knee Surg 2013; December 7 (Epub ahead of print) Ranawat CS, Meftah M, Windsor EN, Ranawat AS. Cementless fixation in total knee arthroplasty: down the boulevard of broken dreams - affirms. J Bone Joint Surg Br 2012;94(11, Suppl A ):82–84 Søballe K. Hydroxyapatite ceramic coating for bone implant fixation. Mechanical and histological studies in dogs. Acta Orthop Scand Suppl 1993;255:1–58 Søballe K, Overgaard S. The current status of hydroxyapatite coating of prostheses. J Bone Joint Surg Br 1996;78(5):689–691 Gejo R, Akizuki S, Takizawa T. Fixation of the NexGen HA-TCPcoated cementless, screwless total knee arthroplasty: comparison with conventional cementless total knee arthroplasty of the same type. J Arthroplasty 2002;17(4):449–456 Søballe K, Hansen ES, Brockstedt-Rasmussen H, Bünger C. Hydroxyapatite coating converts fibrous tissue to bone around loaded implants. J Bone Joint Surg Br 1993;75(2):270–278 Bobyn JD, Stackpool GJ, Hacking SA, Tanzer M, Krygier JJ. Characteristics of bone ingrowth and interface mechanics of a new porous tantalum biomaterial. J Bone Joint Surg Br 1999;81(5): 907–914 Nakama GY, Peccin MS, Almeida GJ, Lira Neto OdeA, Queiroz AA, Navarro RD. Cemented, cementless or hybrid fixation options in total knee arthroplasty for osteoarthritis and other non-traumatic diseases. Cochrane Database Syst Rev 2012;10:CD006193 Berger RA, Lyon JH, Jacobs JJ, et al. Problems with cementless total knee arthroplasty at 11 years followup. Clin Orthop Relat Res 2001;(392):196–207 Duffy GP, Berry DJ, Rand JA. Cement versus cementless fixation in total knee arthroplasty. Clin Orthop Relat Res 1998;(356):66–72 Moran CG, Pinder IM, Lees TA, Midwinter MJ. Survivorship analysis of the uncemented porous-coated anatomic knee replacement. J Bone Joint Surg Am 1991;73(6):848–857 Whiteside LA. Effect of porous-coating configuration on tibial osteolysis after total knee arthroplasty. Clin Orthop Relat Res 1995;(321):92–97 Gandhi R, Tsvetkov D, Davey JR, Mahomed NN. Survival and clinical function of cemented and uncemented prostheses in total knee replacement: a meta-analysis. J Bone Joint Surg Br 2009;91(7): 889–895 Watanabe H, Akizuki S, Takizawa T. Survival analysis of a cementless, cruciate-retaining total knee arthroplasty. Clinical and radiographic assessment 10 to 13 years after surgery. J Bone Joint Surg Br 2004;86(6):824–829 Buechel FF Sr, Buechel FF Jr, Pappas MJ, D’Alessio J. Twenty-year evaluation of meniscal bearing and rotating platform knee replacements. Clin Orthop Relat Res 2001;(388):41–50
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30 Harwin SF, Kester MA, Malkani AL, Manley MT. Excellent fixation
benefit for implant durability of tibial components in primary total knee arthroplasty. Acta Orthop 2011;82(4):448–459 28 Fernandez-Fairen M, Hernández-Vaquero D, Murcia A, Torres A, Llopis R. Trabecular metal in total knee arthroplasty associated with higher knee scores: a randomized controlled trial. Clin Orthop Relat Res 2013;471(11):3543–3553 29 Mikulak SA, Mahoney OM, dela Rosa MA, Schmalzried TP. Loosening and osteolysis with the press-fit condylar posterior-cruciatesubstituting total knee replacement. J Bone Joint Surg Am 2001; 83-A(3):398–403
achieved with cementless posteriorly stabilized total knee arthroplasty. J Arthroplasty 2013;28(1):7–13 31 Beaupré LA, al-Yamani M, Huckell JR, Johnston DW. Hydroxyapatite-coated tibial implants compared with cemented tibial fixation in primary total knee arthroplasty. A randomized trial of outcomes at five years. J Bone Joint Surg Am 2007;89(10):2204–2211 32 Kamath AF, Lee GC, Sheth NP, Nelson CL, Garino JP, Israelite CL. Prospective results of uncemented tantalum monoblock tibia in total knee arthroplasty: minimum 5-year follow-up in patients younger than 55 years. J Arthroplasty 2011;26(8):1390–1395
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27 Voigt JD, Mosier M. Hydroxyapatite (HA) coating appears to be of
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193
Cementless Total Knee Arthroplasty: A Review Jeffrey J. Cherian, DO1 Samik Banerjee, MS (Orth), MRCS (Glasg)1 Bhaveen H. Kapadia, MD1 Julio J. Jauregui, MD1 Steven F. Harwin, MD2 Michael A. Mont, MD1 1 Center for Joint Preservation and Replacement, Rubin Institute for
Advanced Orthopedics, Baltimore, Maryland 2 Department of Orthopaedic Surgery, Beth Israel Medical Center, New York, New York
Address for correspondence Michael A. Mont, MD, Center for Joint Preservation and Replacement, Rubin Institute for Advanced Orthopedics, 2401 West Belvedere Avenue, Baltimore, MD 21215 (e-mail: [email protected]).
Abstract
Keywords
► cementless total knee ► noncemented ► total knee arthroplasty ► implant
There is ongoing debate over the use of cementless fixation in total knee arthroplasty (TKA). Previous generation prostheses resulted in less than optimal outcomes which was somewhat attributed to design issues. As the demand for TKA is continuously increasing and the current U.S. age population is getting younger, cemented fixation may not provide adequate long-term outcomes due to failure of fixation. Thus, there has been a reemergence of the development and use of cementless TKA. Recent short-term trials have demonstrated that modern cementless TKA has comparable survivorship and functional outcomes as cemented prostheses. However, more prospective, randomized trials are needed to clearly delineate any differences between these two fixation options.
Over the past decade, cemented total knee arthroplasty (TKA) has demonstrated excellent clinical outcomes as well as implant survivorship.1 The use of cementless fixation has been available for the past three decades,2,3 but due to less than optimal outcomes with previous generation prostheses, this fixation method never gained popularity.4 Nevertheless, as the indication and numbers of TKA continue to increase, younger and more active patients are undergoing the procedure.5 Therefore, the long-term durability of cemented fixation has come into question in these high-demand patients, because cement has shown to have a poor resistance to shear and tension forces which may result in deformation and degradation over time.6,7 In addition, studies have noted that young and active patients have a higher rate of longterm loosening due to osteolysis present at the cement–bone interface. Recently, cementless TKAs have made a reemergence with newer designs, and manufacturing techniques.8 Studies demonstrated the importance of bone ingrowth that might lead to more long-term implant stability and durability of fixation.9,10 The purpose of this report is to summarize the recent evidence on cementless TKA. This review will specifically focus on the following: (1) History and technology; (2)
received February 19, 2014 accepted March 16, 2014 published online April 24, 2014
Survivorship; (3) Functional outcomes; (4) Economics; and (5) The future outlook of these prostheses.
History and Technology Cementless TKA has been around for more than three decades, but as previously mentioned, due to complications and less than optimal outcomes with first generation prostheses, these implants did not gain favor over their cemented counterparts. They were originally created to improve the longevity of the implants, especially in young and active patients. It is believed that an implant with a more physiological bond between the bone and implant can result in improved survival from aseptic loosening, due to the ability of its interface to respond to stresses in a physiological manner.11 However, the reluctance of cementless use in TKA may have originated from issues developing from screw track osteolysis, poor early polyethylenes, metal-backed patellar failure, and the lack of several press-fit designs failing to demonstrate clinical superiority over cemented implants.5 Another reason for implant failure was the subsidence and failure of the cementless tibial trays, which were originally implanted in cancellous bone instead of upon the cortical rim.12 In
Copyright © 2014 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662.
DOI http://dx.doi.org/ 10.1055/s-0034-1374811. ISSN 1538-8506.
Downloaded by: Washington University. Copyrighted material.
J Knee Surg 2014;27:193–198.
Cementless Total Knee Arthroplasty
Cherian et al.
addition, cementless fixation may be more sensitive to malalignment, especially in relation to the tibial component. This may be because sheer forces applied by varus or valgus tibial base plate positioning can alter the distribution of compressive forces across the implant–bone interface resulting in excessive point loading.13 The recent use of bioactive coating that is sprayed onto the surface of the implant may optimize bony ingrowth.14–16 It is thought that hydroxyapatite coatings act by providing additional anchorage across any motion-induced fibrous membranes between the implant and the bony surface.17 Similarly, newer designs are composed of newer trabecular metals which have been demonstrated to have similar elastic characteristics as bone, and a high level of porosity makes it a favorable environment for bony ingrowth.18 Both of these types of implant designs have been shown on radiostereographic analysis studies that these lead to decreased micromotion compared with traditional press-fit designs and cemented prostheses.19 These fixation characteristics may ultimately predict less risk of late aseptic loosening.
Outcomes of Early Designs Many clinical trials on earlier generation, cementless knee implants have demonstrated that cementless TKA led to poor survivorship outcomes.20–23 A study by Berger et al20 evaluated the long-term survivorship in a series of 131 patients (131 knees) who underwent cementless TKA with a Miller Galante I system (Zimmer Inc, Warsaw, IN). The authors found that there was 8% rate of ingrowth failure, and partial radiolucencies in 53% of the tibias. In addition, they noted that there was a 12% incidence of osteolysis around screw holes at mean follow-up of 11 years. Similarly, Duffy et al,21 in a comparative study, reported on the survivorship of cemented (n ¼ 51) versus noncemented (n ¼ 55) press-fit condylar TKAs at 10-year follow-up. The authors found that there was substantially lower 10-year survivorship in the noncemented group (87.6%) compared with cemented (96.1%) cohort. Exclusive on elevation of problems related to the metal-backed patellar, survival to revision for aseptic failure, or radiographic loosening was higher in the uncemented than the cemented group at 10 years (72 vs. 94%). A meta-analysis by Gandhi et al24 evaluated the survivorship of cemented and cementless TKA in 11 studies (5 randomized controlled trials and 10 observational studies). The authors reported that the odds ratio (OR) for failure of the implant due to aseptic loosening for the uncemented cohort was 4.2 (p < 0.0001) and the cumulative data from the 15 studies revealed a more favorable outcome for cemented fixation. However, when isolated evaluation of the five randomized control trials was performed the authors were unable to demonstrate differences in survivorship between the two cohorts. The authors attributed the higher failure rates of cementless prostheses in observational studies to younger age and increased activity levels of the patient populations who had undergone cementless TKAs. Interestingly, even though a variety of implants were analyzed, none were hydroxyapatite coated. The Journal of Knee Surgery
Vol. 27
No. 3/2014
However, there were some prosthesis that were able to achieve successful long-term survivorship and outcomes.9,10,25,26 A study by Whiteside10 evaluated the survivorship of 129 patients (163 Ortholoc I; Wright Medical Technology, Arlington, TN) who underwent TKA with cementless tibial and femoral components at 9 to 11 years of follow-up. The authors observed loosening in only one knee during the follow-up period that required revision surgery. Considering all modes of failure, survival rate at 10 years was 94%. In addition, 10 years after surgery, 83.7% of patients had no pain at final follow-up. Thus, there is conflicting evidence concerning the use cementless TKA from historical reports. Nevertheless, more recent studies have reported comparable long-term survivorship and clinical outcomes between cementless and cemented TKA, and these results may be attributed to the newer generation of cementless surfaces and highly porous metals.
Outcomes of Newer Designs Despite the first generation clinical trials that demonstrated that selected cementless TKA led to poor survivorship, more recent designs have comparable outcomes to those of cemented prostheses. A recent systemic review and meta-analysis by Mont et al12 examined 37 studies (3,568 TKAs in 2,940 patients) comparing cementless to cemented TKA. The authors found that cementless TKA had implant survivorship comparable to cemented TKA (OR, 1.1). The mean survivorships were 95.6 and 95.3% for cementless and cemented TKA, respectively at 10-year follow-up. At 20-year follow-up, the authors demonstrated that implant survivorship decreased to 76 and 71% for cemented and cementless, respectively. In addition, they analyzed the use of screw fixation to implant survivorship, and found that no differences were observed between fixation with or without screws (relative risk [RR], 1.1). However, the authors did not differentiate between which implant designs were used. Another systematic review study by Voigt and Mosier27 evaluated implant durability using radiostereographic analysis in three groups of patients (hydroxyapatite [HA] coated, porous coated, and cemented). This study consisted of 926 primary TKAs from 14 studies. The authors noted that HA-coated tibial components without screw fixation were less likely to be unstable at 2 years than porous and cemented tibial components (RR ¼ 0.58, p ¼ 0.04). In addition, there were no significant differences in revision rates at 2 and 8 to 10 years of follow-up, between the groups. A prospective randomized trial of 145 TKAs by FernandezFairen et al28 compared the use of trabecular metal TKA to those performed with cemented implants. The authors found that at 5-year follow-up, the mean Knee Society scores (KSS) was 90.4 (range, 68–100) for trabecular metal cohort, and 86.5 (range, 56–99) for cemented cohort (p ¼ 0.02). In addition, they reported that the mean Western Ontario and McMaster Universities osteoarthritis index (WOMAC) score was 15.1 (range, 0–51) for patients who had received the trabecular metal prosthesis, and 19.1 (range, 4–61) for those who had cemented TKAs (p ¼ 0.02).
Downloaded by: Washington University. Copyrighted material.
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Harwin et al30 on the use of cementless posterior stabilizing knee arthroplasty has demonstrated excellent short-term results that contradict this notion. In this prospective series of 110 patient (114 knees), the authors reported that at a mean follow-up of 36 months (range, 24–50 months), all patients demonstrated to have stable biological fixation with no evidence of loosening, stress shielding, or progressive radiolucencies.30 Given the positive results reported with the newer generation prostheses, we believe that cementless TKAs are comparable alternatives to cemented TKAs in terms of survivorship and clinical outcomes. Please refer to ►Table 1 for a brief summary of reviewed studies.
Economic Perspective With recent health care policy changes and concerns of related costs, implant effectiveness has become an important topic of discussion. Components of cementless TKA have been estimated to cost up to three times more than cemented prostheses.31 Although the direct cost associated with the prosthesis may be higher than their cemented counterparts, the cost per procedure has been shown to be lower with cementless designs.12 This is due to the need for fewer supplies in the operating room.32 Kamath et al32 found that
Table 1 Summary of cementless TKA studies Study, year
Number of knees
Mean follow-up (y)
Brief summary of results
Duffy et al, 199821
102
10
Patients who underwent cementless TKA had lower survivorship than cemented counterpart
Gandhi et al, 200924
–
–
Patient who underwent cementless TKA had higher OR for failure of the implant due to aseptic loosening (OR ¼ 4.2)
Whiteside, 199410
163
10
The authors found that there was a 96.3% survivorship with the use of cementless TKA
Berger et al, 200120
131
11
Early tibial design had an 8% rate of ingrowth failure, and partial radiolucencies in 53% of their tibias
Mont et al, 201312
3,568
10 and 20
Cementless TKA had implant survivorship comparable to cemented TKA (OR, 1.1; 95.6 vs. 95.3%) at 10-year follow-up; at 20 year follow-up, survivorship decreased to 76 and 71% for cemented and cementless, respectively
Voigt and Mosier, 201127
926
2 and 8
HA-coated tibial components without screw fixation were less likely to be unstable at 2 years than porous and cemented tibial components (RR ¼ 0.58, p ¼ 0.04)
Fernandez-Fairen et al, 201328
145
5
Patients in the trabecular metal cementless cohort had significantly higher KSS and WOMAC scores than cemented counterpart
Kim et al, 20141
160
17
Cemented tibial component survival rate was 100%, and the cementless tibial component 98.7%; no significant differences were seen between cementless and cemented total knee arthroplasty in mean KSS, WOMAC index, and ROM
Harwin et al, 201330
114
3
Cementless posterior stabilizing knee arthroplasty at latest follow-up had no radiographic evidence of loosening or stress shielding and all implants had stable biologic fixation
Abbreviations: HA, hydroxyapatite; KSS, Knee Society score; OR, odds ratio; ROM, range of motion; RR, relative risk; TKA, total knee arthroplasty; WOMAC, Western Ontario and McMaster Universities osteoarthritis index. The Journal of Knee Surgery
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A recently published prospective randomized trial by Kim et al1 examined patient satisfaction, long-term clinical, and implant survivorship rates in 80 patients (160 knees) younger than 55 years (mean age, 54.3 years) who had underwent bilateral, sequential, simultaneous TKAs where one knee received a cemented prostheses, and the other was trabecular metal cementless implant (NexGen CR; Zimmer, Warsaw, IN). The authors found that patients described comparable satisfaction 8.1 points for cementless compared with 8.3 points for cemented. On analysis of component survivorship, the authors reported that the femoral component had a 100% survival rate in both the groups at 17-year follow-up. The cemented tibial component survival rate was 100% and the cementless tibial component 98.7% at 17-year follow-up, with no incidence osteolysis being identified in either group. Also, authors noted that there were no significant differences between cementless and cemented TKA in mean KSS (95.8 vs. 96.9), WOMAC (25.4 vs. 25.9), and range of motion (125 vs. 128 degrees). Furthermore, historically the use of posterior stabilizing designs in cementless knee arthroplasty was controversial, due to the unpredictable results from stresses placed on the tibial interface from the cam/postinteraction.29 This interaction was thought to potentially cause micromotion prohibiting biologic fixation, however, a recent landmark study by
Cherian et al.
Cementless Total Knee Arthroplasty
Cherian et al.
at their institution the use of cementless prosthesis cost approximately $596 more than its cemented counterpart. However, after deduction of the cement, operating time, and mixing equipment, there was only a $150 cost difference. In addition, cementless TKA offers the potential advantage of being a shorter procedure with decreased tourniquet times, thus further reducing overall operating costs. One might note that, cement may potentially have the added cost benefit of allowing the delivery of antibiotics directly into the joint, potentially reducing the risk of periprosthetic infections in the population, which may need to be considered when weighting cost benefit analysis of these prostheses.
7
8
9
10
11
Future Outlook The recent generations of cementless TKAs may have survivorship and functional outcomes comparable to those of cemented prostheses. Radiostereographic studies have shown that the new generation of implants with hydroxyapatite bioactive coatings or those made from highly porous metals have superior fixation compared with those without these material properties. We believe these technologies have made the use of press-fits stems a viable option for TKA in the young population. Cost analyses studies are required to assess whether the use should be routine in TKA.
12
13
14
15 16
Conclusion Cementless TKA is a potential fixation option for patients with end-stage knee osteoarthritis, however, multiple prior studies of historically made prostheses raised questions regarding the longevity of these implants compared with the current standard cemented TKA. Recent studies have shown that modern cementless TKA appears to have similar outcomes as compared with cemented total knees at equivalent lengths of follow-up. More prospective, randomized trials are needed to clearly delineate any differences between these two fixation options given the discrepancy in survivorship that has previously been reported.
17
18
19
20
21 22
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2
3 4 5
6
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cadaver study comparing cemented and cementless fixation techniques. Acta Orthop Belg 2011;77(3):320–328 McCaskie AW, Deehan DJ, Green TP, et al. Randomised, prospective study comparing cemented and cementless total knee replacement: results of press-fit condylar total knee replacement at five years. J Bone Joint Surg Br 1998;80(6):971–975 Azboy I, Demirtaş A, Bulut M, Oztürkmen Y, Sükür E, Caniklioğlu M. Long-term results of porous-coated cementless total knee arthroplasty with screw fixation. Acta Orthop Traumatol Turc 2013;47(5):347–353 Hofmann AA, Evanich JD, Ferguson RP, Camargo MP. Ten- to 14year clinical followup of the cementless Natural Knee system. Clin Orthop Relat Res 2001;(388):85–94 Whiteside LA. Cementless total knee replacement. Nine- to 11year results and 10-year survivorship analysis. Clin Orthop Relat Res 1994;(309):185–192 Brown TE, Harper BL, Bjorgul K. Comparison of cemented and uncemented fixation in total knee arthroplasty. Orthopedics 2013; 36(5):380–387 Mont MA, Pivec R, Issa K, Kapadia BH, Maheshwari A, Harwin SF. Long-term implant survivorship of cementless total knee arthroplasty: a systematic review of the literature and meta-analysis. J Knee Surg 2013; December 7 (Epub ahead of print) Ranawat CS, Meftah M, Windsor EN, Ranawat AS. Cementless fixation in total knee arthroplasty: down the boulevard of broken dreams - affirms. J Bone Joint Surg Br 2012;94(11, Suppl A ):82–84 Søballe K. Hydroxyapatite ceramic coating for bone implant fixation. Mechanical and histological studies in dogs. Acta Orthop Scand Suppl 1993;255:1–58 Søballe K, Overgaard S. The current status of hydroxyapatite coating of prostheses. J Bone Joint Surg Br 1996;78(5):689–691 Gejo R, Akizuki S, Takizawa T. Fixation of the NexGen HA-TCPcoated cementless, screwless total knee arthroplasty: comparison with conventional cementless total knee arthroplasty of the same type. J Arthroplasty 2002;17(4):449–456 Søballe K, Hansen ES, Brockstedt-Rasmussen H, Bünger C. Hydroxyapatite coating converts fibrous tissue to bone around loaded implants. J Bone Joint Surg Br 1993;75(2):270–278 Bobyn JD, Stackpool GJ, Hacking SA, Tanzer M, Krygier JJ. Characteristics of bone ingrowth and interface mechanics of a new porous tantalum biomaterial. J Bone Joint Surg Br 1999;81(5): 907–914 Nakama GY, Peccin MS, Almeida GJ, Lira Neto OdeA, Queiroz AA, Navarro RD. Cemented, cementless or hybrid fixation options in total knee arthroplasty for osteoarthritis and other non-traumatic diseases. Cochrane Database Syst Rev 2012;10:CD006193 Berger RA, Lyon JH, Jacobs JJ, et al. Problems with cementless total knee arthroplasty at 11 years followup. Clin Orthop Relat Res 2001;(392):196–207 Duffy GP, Berry DJ, Rand JA. Cement versus cementless fixation in total knee arthroplasty. Clin Orthop Relat Res 1998;(356):66–72 Moran CG, Pinder IM, Lees TA, Midwinter MJ. Survivorship analysis of the uncemented porous-coated anatomic knee replacement. J Bone Joint Surg Am 1991;73(6):848–857 Whiteside LA. Effect of porous-coating configuration on tibial osteolysis after total knee arthroplasty. Clin Orthop Relat Res 1995;(321):92–97 Gandhi R, Tsvetkov D, Davey JR, Mahomed NN. Survival and clinical function of cemented and uncemented prostheses in total knee replacement: a meta-analysis. J Bone Joint Surg Br 2009;91(7): 889–895 Watanabe H, Akizuki S, Takizawa T. Survival analysis of a cementless, cruciate-retaining total knee arthroplasty. Clinical and radiographic assessment 10 to 13 years after surgery. J Bone Joint Surg Br 2004;86(6):824–829 Buechel FF Sr, Buechel FF Jr, Pappas MJ, D’Alessio J. Twenty-year evaluation of meniscal bearing and rotating platform knee replacements. Clin Orthop Relat Res 2001;(388):41–50
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benefit for implant durability of tibial components in primary total knee arthroplasty. Acta Orthop 2011;82(4):448–459 28 Fernandez-Fairen M, Hernández-Vaquero D, Murcia A, Torres A, Llopis R. Trabecular metal in total knee arthroplasty associated with higher knee scores: a randomized controlled trial. Clin Orthop Relat Res 2013;471(11):3543–3553 29 Mikulak SA, Mahoney OM, dela Rosa MA, Schmalzried TP. Loosening and osteolysis with the press-fit condylar posterior-cruciatesubstituting total knee replacement. J Bone Joint Surg Am 2001; 83-A(3):398–403
achieved with cementless posteriorly stabilized total knee arthroplasty. J Arthroplasty 2013;28(1):7–13 31 Beaupré LA, al-Yamani M, Huckell JR, Johnston DW. Hydroxyapatite-coated tibial implants compared with cemented tibial fixation in primary total knee arthroplasty. A randomized trial of outcomes at five years. J Bone Joint Surg Am 2007;89(10):2204–2211 32 Kamath AF, Lee GC, Sheth NP, Nelson CL, Garino JP, Israelite CL. Prospective results of uncemented tantalum monoblock tibia in total knee arthroplasty: minimum 5-year follow-up in patients younger than 55 years. J Arthroplasty 2011;26(8):1390–1395
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