The Paradox of the Decline of Cemented Femoral Stems

The use of cemented stems in total hip arthroplasty (THA) has been declining for several years. However, these implants do not seem to have disappointed either surgeons or patients. Thus, herein lies the paradox of an implant that provides the expected result and yet is in the process of being abandoned. In the absence of large-scale, long-term randomized prospective series, national registers provide valid elements of comparison. Troelsen et al. in 2013 analyzed 7 national registries (Australia, Canada, England, Denmark, New Zealand, Norway, and Sweden) showing a steady increase in the use of uncemented prostheses in these countries until 2010 [[1]Troelsen A. Malchau E. Sillesen N. Malchau H. A review of current fixation use and registry outcomes in total hip arthroplasty: the uncemented paradox.Clin Orthop Relat Res. 2013; 471: 2052-2059Crossref PubMed Scopus (146) Google Scholar]. The recent update of this study in 2019 highlighted a “cementless” trend between 2010 and 2020 that had increased in some countries but seemed to be reversing in others (England and Wales, Australia, New Zealand, and Finland) [[2]Bunyoz K.I. Malchau E. Malchau H. Troelsen A. Has the use of fixation techniques in THA changed in this decade? The uncemented paradox revisited.Clin Orthop Relat Res. 2020; 478: 697-704Crossref PubMed Scopus (30) Google Scholar]. The authors agree in these 2 analyses that survival was significantly better for cemented prostheses in people older than 70-75 years, in all registers. For the other age groups, survival was better for cemented prostheses, or equivalent, except in the Australian register. This type of global analysis can also be done through a meta-analysis. Phedy et al. [[3]Phedy P. Ismail H.D. Hoo C. Djaja Y.P. Total hip replacement: a meta-analysis to evaluate survival of cemented, cementless and hybrid implants.World J Orthop. 2017; 8: 192-207Crossref PubMed Scopus (13) Google Scholar], in a meta-analysis including 27 studies, showed very similar results in terms of survival, with equivalence in the youngest and superiority of cemented fixation in the oldest. The question of young subjects remains highly controversial. Here again, the registers make it possible to provide elements of comparison. The Nordic Arthroplasty Register Association (NARA) [[4]Pedersen A.B. Mehnert F. Havelin L.I. Furnes O. Herberts P. Kärrholm J. et al.Association between fixation technique and revision risk in total hip arthroplasty patients younger than 55 years of age. Results from the Nordic Arthroplasty Register Association.Osteoarthritis Cartilage. 2014; 22: 659-667Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar], which collected data on 29,558 hips in patients younger than 55 years, did not find any difference in the overall revision rate. However, this equivalence was the result of a balance between revisions for aseptic loosening, with a favorable rate for uncemented implants (Risk ratio [RR] = 0.5, confidence interval [CI]: 0.5-0.6), counterbalanced by other causes of revisions, particularly fractures (RR = 2.6). The occurrence of a periprosthetic fracture is a known complication of THA. The risk of periprosthetic fracture depends on the type of implant used and the postoperative term. The meta-analysis of Bissias et al. [[5]Bissias C. Kaspiris A. Kalogeropoulos A. Papoutsis K. Natsioulas N. Barbagiannis K. et al.Factors affecting the incidence of postoperative periprosthetic fractures following primary and revision hip arthroplasty: a systematic review and meta-analysis.J Orthop Surg Res. 2021; 16: 15Crossref PubMed Scopus (12) Google Scholar], with data on 599,551 THAs, showed that the use of a cemented stem reduced the relative risk of periprosthetic fracture to 0.41 (95% CI: 0.19-0.62). Lindberg-Larsen et al. [[6]Lindberg-Larsen M. Jørgensen C.C. Solgaard S. Kjersgaard A.G. Kehlet H. Increased risk of intraoperative and early postoperative periprosthetic femoral fracture with uncemented stems.Acta Orthop. 2017; 88: 390-394Crossref PubMed Scopus (72) Google Scholar], in an analysis of 7169 THAs, observed a relative risk of fracture of 4.1 (95% CI: 2.3-7.2) for uncemented stems. The risk of fracture is present postoperatively (RR = 1.8 at 2 years), but it also persists over time [[4]Pedersen A.B. Mehnert F. Havelin L.I. Furnes O. Herberts P. Kärrholm J. et al.Association between fixation technique and revision risk in total hip arthroplasty patients younger than 55 years of age. Results from the Nordic Arthroplasty Register Association.Osteoarthritis Cartilage. 2014; 22: 659-667Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar]. However, not all cemented stems are created equal. The National Health Service registry (United Kingdom) [[7]Palan J. Smith M.C. Gregg P. Mellon S. Kulkarni A. Tucker K. et al.The influence of cemented femoral stem choice on the incidence of revision for periprosthetic fracture after primary total hip arthroplasty: an analysis of national joint registry data.Bone Joint J. 2016; 98-B: 1347-1354Crossref PubMed Scopus (58) Google Scholar] showed a variable risk of fracture among 257,202 cemented stems: RR of 1 for an Exeter-type stem, 0.88 for the C-stem (Depuy Synthes, Raynham, MA), and 0.41 for Charnley-type stems. To our knowledge, there is no study stratifying cementless stem types and fracture risk. This should be done according to the classification suggested by Khanuja et al. [[8]Khanuja H.S. Vakil J.J. Goddard M.S. Mont M.A. Cementless femoral fixation in total hip arthroplasty.J Bone Joint Surg Am. 2011; 93: 500-509Crossref PubMed Scopus (337) Google Scholar]. Similarly, there is no information on the impact of bone quality, cortical thickness, and patient characteristics other than age on the choice of cemented or uncemented stems. This should be evaluated in future studies. The risk of periprosthetic fractures when using a cemented stem is higher when the prosthesis is placed for a femoral neck fracture, RR of 5.1 in the Norwegian registry [[9]Kristensen T.B. Dybvik E. Kristoffersen M. Dale H. Engesæter L.B. Furnes O. et al.Cemented or uncemented hemiarthroplasty for femoral neck fracture? Data from the Norwegian hip fracture register.Clin Orthop Relat Res. 2020; 478: 90-100Crossref PubMed Scopus (61) Google Scholar]. In this indication, mortality is the primary endpoint. The postoperative term seems to determine the outcome. The Norwegian registry highlights very early excess mortality for cemented stems (RR = 0.7, 95% CI: 0.5-0.9, P < .001 on postoperative day 7) [[9]Kristensen T.B. Dybvik E. Kristoffersen M. Dale H. Engesæter L.B. Furnes O. et al.Cemented or uncemented hemiarthroplasty for femoral neck fracture? Data from the Norwegian hip fracture register.Clin Orthop Relat Res. 2020; 478: 90-100Crossref PubMed Scopus (61) Google Scholar]. This difference is then reduced over time due to higher rates of complications, notably fractures, and revisions for uncemented stems (RR = 1.5, 95% CI: 1.4-1.7, P < .001). There is no longer a difference after 1 year. Bone cement implantation syndromes are rare and occur in operations in elderly subjects (average age of 85 years) and remind us of the importance of respecting precautions and contraindications. Also, Veldman et al. [[10]Veldman H.D. Heyligers I.C. Grimm B. Boymans T.a.EJ. Cemented versus cementless hemiarthroplasty for a displaced fracture of the femoral neck: a systematic review and meta-analysis of current generation hip stems.Bone Joint J. 2017; 99-B: 421-431Crossref PubMed Scopus (83) Google Scholar], in a meta-analysis of 5 randomized controlled trials and 950 patients, observed no difference in mortality at 1 month, 1 year, and 5 years and more complications for uncemented recent stems (odds ratio: 1.61) but also the benefit of a shorter operating time by 9.96 minutes. The risk of intraoperative or postoperative periprosthetic fractures was at least 3 times higher for uncemented stems. No significant differences were found in cardiovascular complications, including bone cement implantation syndromes. Bone cement implantation syndromes and stem loosening could be 2 arguments against cemented stems. Regarding bone cement implantation syndromes, according to Costa et al., there is no increase in perioperative mortality in cemented stems compared to uncemented stems [[11]Costa M.L. Griffin X.L. Pendleton N. Pearson M. Parsons N. Does cementing the femoral component increase the risk of peri-operative mortality for patients having replacement surgery for a fracture of the neck of femur? Data from the National Hip Fracture Database.J Bone Joint Surg Br. 2011; 93: 1405-1410Crossref PubMed Scopus (44) Google Scholar]. Although some studies disagree on this point and find an increase in perioperative mortality with cemented stems, this is quickly counterbalanced after a week by an increase in postoperative mortality in uncemented stems, which seems to be consequent to more frequent periprosthetic fractures [[12]Costain D.J. Whitehouse S.L. Pratt N.L. Graves S.E. Ryan P. Crawford R.W. Perioperative mortality after hemiarthroplasty related to fixation method.Acta Orthop. 2011; 82: 275-281Crossref PubMed Scopus (73) Google Scholar]. In the case of aseptic loosening, the longevity of cemented stems is not inferior to that of uncemented stems, and revision can be performed by the cement-in-cement technique in selected cases [[13]Malahias M.A. Mancino F. Agarwal A. Roumeliotis L. Gu A. Gkiatas I. et al.Cement-in-cement technique of the femoral component in aseptic total hip arthroplasty revision: a systematic review of the contemporary literature.J Orthop. 2021; 26: 14-22Crossref PubMed Scopus (4) Google Scholar,[14]Hailer N.P. Garellick G. Kärrholm J. Uncemented and cemented primary total hip arthroplasty in the Swedish Hip Arthroplasty Register.Acta Orthop. 2010; 81: 34-41Crossref PubMed Scopus (341) Google Scholar]. This is not the case for septic loosening, which requires an extensive trochanteric osteotomy to remove the cement, which is a strong disadvantage of the cemented stems. These unanimous data led the American Academy of Orthopedic Surgery to recommend the placement of cemented prostheses in neck fractures [[15]Brox W.T. Roberts K.C. Taksali S. Wright D.G. Wixted J.J. Tubb C.C. et al.The American Academy of orthopaedic surgeons evidence-based guideline on management of hip fractures in the elderly.J Bone Joint Surg Am. 2015; 97: 1196-1199Crossref PubMed Scopus (142) Google Scholar]. This clinical benefit is associated with an economic benefit. Blythe et al. [[16]Blythe R. O’Gorman P.M. Crawford R.W. Feenan R. Hatton A. Whitehouse S.L. et al.Fixation method for hip arthroplasty stem following hip fracture: a population-level cost-effectiveness analysis.J Arthroplasty. 2020; 35: 1614-1621Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar], in an Australian study, calculated that changing current practices for cervical hip fractures from a widespread use of uncemented to cemented-stem arthroplasties would save the Australian health-care system $2.0 million over 5 years with a gain of 203 years of life for the patients. The U.S. Medicare system reported equivalent results, where cemented and uncemented stems had similar clinical outcomes, but with lower implant costs, shorter lengths of stay, and lower readmission and revision rates in favor of cemented stems [[17]Oh J.H. Yang W.W. Moore T. Dushaj K. Cooper H.J. Hepinstall M.S. Does femoral component cementation affect costs or clinical outcomes after hip arthroplasty in medicare patients?.J Arthroplasty. 2020; 35: 1489-1496.e4Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar]. What are the causes of this paradox? Two arguments are sometimes put forward: the gradual loss of cemented stem implantation experience in training centers and a slightly longer operating time. However, we should remember that the difference in operating time is only about 10 minutes. Other factors are probably involved, perhaps predominantly, such as the “trend effect” and the appeal of novelty or even the marketing actions of manufacturers. We must remain aware of these debates and enlighten them with robust practical studies, otherwise health-care policies, public and private, will be driven by coercive measures, and a lack of discernment is to be expected. To avoid this, it seems crucial to study why surgeons do not base their practices on evidence-based recommendations [[18]Chang J. McGrory B.J. Rana A. Becker M.W. Babikian G.M. Guay P. et al.Current orthopaedic surgeon practices for nonarthroplasty treatment of osteoarthritis of adult hip and knee.J Surg Orthop Adv. 2015; 24: 213-220Crossref PubMed Google Scholar]. A better understanding of this phenomenon would help improve surgeon training on this topic and prevent this type of situation. Pr. Dujardin reports academic support from Amplitude, Serf, Stryker, Zimmer, Heraeus, and Leo Pharma, outside the submitted work. All other authors declare no potential conflicts of interest. For full disclosure statements refer to https://doi.org/10.1016/j.artd.2022.10.007. The authors are grateful to Nikki Sabourin-Gibbs, Rouen University Hospital, for her help in editing the manuscript. Download .pdf (.11 MB) Help with pdf files Conflict of Interest Statement for Dujardin Download .pdf (.1 MB) Help with pdf files Conflict of Interest Statement for Curado Download .pdf (.1 MB) Help with pdf files Conflict of Interest Statement for Matsoukis Download .pdf (.1 MB) Help with pdf files Conflict of Interest Statement for Lalevée Download .pdf (.1 MB) Help with pdf files Conflict of Interest Statement for De Sulauze