Radiological and clinical outcomes of cementless versus cemented implants in total knee arthroplasty

Aims With the increasing use of cementless implants for primary total knee arthroplasty (TKA), the aim of this systematic review and meta-analysis was to evaluate the clinical and radiological outcomes of contemporary cementless designs of TKA compared with cemented TKA. Methods Adhering to the PRISMA guidelines, a review of medical databases including Cochrane Registry, MEDLINE, Embase, Web of Science, and grey literature was conducted. The search included studies published since 2010 and encompassed only the current generation of cementless implants. Quality assessment was performed using the ROB-2/ROBIN-I risk of bias tools. Results The search yielded 23 randomized controlled trials and 45 observational studies which met the inclusion criteria. A total of 31 outcome metrics, including clinical and functional outcomes, were analyzed. Subgroup analysis was based on the patient’s age. Meta-analysis of all-cause and aseptic survival at specific timepoints between one and 19 years postopertaively showed no significant difference between the groups. Subgroup analysis for individual patients aged < 60 years showed significant differences favouring cementless implants up to 14 years. Overall migration, measured at one and five years, was significantly higher for cementless implants (p < 0.001), with comparable migration at ten years (p = 0.43). Meta-analysis of most clinical outcomes showed equivalence up to 20 years, though some metrics favoured cementless implants. Subscales of Knee Society Score function/pain revealed significant differences at two (p = 0.003) and five years (all p < 0.05) favouring cementless implants. Cementless groups also had significantly shorter operating times (p < 0.001) and lengths of stay in hospital (p = 0.003). Surgical complications were significantly more frequent in the cemented group (p < 0.001), as was the incidence of deep venous thrombosis (p = 0.002). Conclusion This meta-analysis highlighted considerable variations in outcomes between cemented and cementless TKA, suggesting that newer designs of cementless implants may offer improved survival in patients aged < 60 years. There was early migration of cementless TKA with stabilization in the longer term and improvement in several clinical and functional outcomes favouring cementless over cemented implants. Cite this article: Bone Joint J 2025;107-B(10):995–1003.