Eight studies in the past 20 years have directly compared the clinical and/or radiologic outcomes between both modes of stem fixation. Seven were nonrandomized cohort studies and 1 was randomized controlled level 1 study. Fehring et al reported a comparative analysis of stem fixation in 113 revisions with 202 metaphyseal engaging stems. Diaphyseal engaging press-fit stems were excluded. Results showed that 29% of press-fit noncemented stems were unstable compared with 7% of fully cemented stems according to a radiological analysis. Gilliland et al reviewed 82 revisions at a midterm follow-up. Thirty-three were hybrid and 49 were fully cemented stem fixation. Re-revision and radiographic failure rates were similar between groups with similar improvements also noted in the knee society clinical scores. This result emphasizes the need for diaphyseal engagement with hybrid fixation and explains the poor result noted in the study by Fehring et al. Cintra et al examined tibial implant fixation in 30 rTKA in 26 patients: 21 fully cemented and 9 hybrid stems. At a mean 52-month follow-up, no difference in clinical, radiographic, or survival outcome was observed. Edwards et al examined 114 patients who underwent 2-stage revision (102 cemented and 126 hybrid stems) for infection. At a mean of 45 months of follow-up (cemented) and 52 months (cemented), aseptic loosening, reinfection, and clinical outcomes were identical, but cemented stems were statistically more likely to be radiologically loose. Kosse et al in a randomized controlled study compared the performance of 12 fully cemented and 11 hybrid stem fixations using radiostereometric analysis. At a mean 6.5-year follow-up, they did not observe any statistically significant difference in median micromotion and clinical outcome between both modes of fixation. Fleischman et al examined 223 revisions in 220 patients (108 fully cemented and 316 hybrid). At a mean of 64.3 months (cemented) and 59.6 months (noncemented) of follow-up, no difference was observed in mechanical failure and infection rates in either mode of fixation. Lachiewicz et al reported 84 revisions (34 fully cemented and 50 hybrid stem fixations) in which femoral stem was used. . Similar improvement in clinical outcomes was observed between groups, and no significant difference was noted in radiographic failure and aseptic loosening rates. Gomez-Vallejo et al examined 67 patients (29 cemented and 38 hybrid stems). At a mean follow-up of 7 years, statistically significant improvement was observed in the Western Ontario and McMaster Universities Osteoarthritis Index scores (total and subgroup) in favor of hybrid stem fixation, all other clinical and survival-related variables being similar. The authors concluded that although results were similar between groups, hybrid fixation tended to produce better results than cemented stem fixation. The studies overall were of low to moderate quality and showed high clinical heterogeneity.
J Am Acad Orthop Surg. 2022;30(9):e703-e713. © 2022 American Academy of Orthopaedic Surgeons