Abstract
Over the past 30 years, cemented, cementless, and hybrid fixation options have been utilised with various total knee arthroplasty (TKA) implant systems. While cemented components are widely used and considered the most reliable method of fixation, historical results may not be applicable to contemporary patients, who are increasingly younger than 65 years of age. Moreover, the literature is not definitive on which method of TKA fixation obtains the best clinical, functional, and radiographic results. A recent Cochrane meta-analysis on roentgen stereophotogrammetric analysis (RSA) included five randomised clinical trials (RCTs) in 297 participants. The authors observed that cemented fixation of tibial components demonstrated smaller displacement in relation to cementless fixation. However, the risk of future aseptic loosening with uncemented fixation was approximately half that of cemented fixation (risk ratio = 0.47, 95% CI 0.24 to 0.92) with a 16% absolute risk difference between groups. Almost all included studies recorded functional measures of Knee Society and Hospital for Special Surgery knee scores, but the authors of each study found no significant difference between the groups. Recently, highly porous metals have become an attractive fixation option in TKA due to their biomechanical properties. In a large RCT of 397 patients, Pulido et al found that uncemented highly porous metal tibias provided comparably durable fixation and reliable pain relief and restoration of function when compared with traditional cemented modular tibias. While longer term studies are needed, cementless TKAs may be a durable and reliable alternative with highly porous metals, particularly in younger patients.
