Postoperative Infection in Cementless and Cemented Total Knee Arthroplasty: A Propensity Score Matched Analysis
Hiba K. Anis, Deepak Ramanathan, Nipun Sodhi, Alison K. Klika, Nicolas S. Puizzi, Michael A. Mont, Carlos A Higuera, Robert M. Molloy
J Knee Surg. 2019 Nov;32(11):1058-1062.
doi: 10.1055/s-0039-1678678. Epub 2019 Feb 12. PMID: 30754069.
Summary by Santiago Restrepo, BS
With younger patients accounting for a larger portion of people requiring total knee arthroplasty (TKA) there is increasing interest in cementless procedures [1–3]. Although some recent studies have shown that survivorship and clinical outcomes of new cementless TKA are comparable to cemented TKA, only a few older studies have analyzed the infection rates between both systems of fixation [4]. A propensity score matched study between cemented and cementless TKA to compare postoperative infection rates may provide more information when surgeons are deciding between modes of fixation.
Anis et al. presented an analysis of the infection rates across matched groups of cemented and cementless TKA systems. The propensity score matched analysis accounted for patient and procedure-related factors to allow for a comparison of the rate of infection between the two modes of fixation. In their study, 3,180 patients (133 cementless and 3,047 cemented) from an institutional database had an average follow-up of 27 months when electronic medical records were reviewed for diagnosis of either prosthetic joint infection (PJI) or surgical site infection (SSI). Across the study population, the overall infection rate was 3.0%, of which PJI was 1.9% and SSI was 1.1%. For the cementless cohort, overall infection rate was 3.8%; for the cemented cohort, overall infection rate was 2.3%. Neither PJI nor SSI had a significant association between rate of infection and mode of fixation. PJI incidence was 2.3% for the cementless cohort and 1.5% for cemented. SSI incidence was 1.5% for the cementless cohort and 0.8% for cemented. The authors suggest a larger study population given the relatively rare postoperative infection rates. Although the matched-propensity score allowed for many factors to be accounted for in the statistical model, bone quality and surgeon preference likely also affect the fixation modality, but were not controlled for in the study. The study suggests that both cementless and cemented procedures have comparable rates of postoperative infection for both PJI or SSI, after accounting for various patient and procedural factors.
References:
- Mont MA, Gwam C, Newman JM, Chughtai M, Khlopas A, Ramkumar PN, et al. Outcomes of a newer-generation cementless total knee arthroplasty design in patients less than 50 years of age. Ann Transl Med 2017;5:S24. https://doi.org/10.21037/atm.2017.08.20.
- Kim Y-H, Park J-W, Lim H-M, Park E-S. Cementless and cemented total knee arthroplasty in patients younger than fifty five years. Which is better? Int Orthop 2014;38:297–303. https://doi.org/10.1007/s00264-013-2243-4.
- Hofmann AA, Heithoff SM, Camargo M. Cementless total knee arthroplasty in patients 50 years or younger. Clin Orthop 2002:102–7. https://doi.org/10.1097/00003086-200211000-00018.
- Jämsen E, Huhtala H, Puolakka T, Moilanen T. Risk factors for infection after knee arthroplasty. A register-based analysis of 43,149 cases. J Bone Joint Surg Am 2009;91:38–47. https://doi.org/10.2106/JBJS.G.01686.
