Comparison of mid-term survival of uncemented total knee arthroplasties with modular tibial components made of porous tantalum vs. cemented total knee arthroplasties

Background & objectives Cementless total knee arthroplasties (TKAs) with porous tantalum tibial components were developed to improve fixation and reduce implant failure rates in younger, active patients. However, mid-term outcomes remain uncertain. This retrospective study compared survival rates of cementless TKAs with porous tantalum posterior-stabilized (PS) modular tibial components to cemented PS components from the same implant system, using revision for aseptic loosening as the endpoint.Materials and methods From January 2017 to November 2021, 899 TKAs were performed at a single tertiary center for osteoarthritis. Of these, 645 (71.7%) were cemented and 254 (28.3%) cementless. Median BMI was similar in both groups (30.0 kg/m2 vs 31.0 kg/m2; p = 0.814). Cementless recipients were younger (median 66.0 vs. 72.0 years; p < 0.001). Follow-up continued through 31 December 2023.Results Seven-year survival was lower in the cementless group (97.1%, 95% CI 94.9–99.3) vs. cemented group (97.8%, 95% CI 96.6–99.0). Tibial component loosening led to 5 revisions in the cementless group vs. 2 revisions in the cemented group (p < 0.05). Two cementless cases involved tibial tray fractures. Overall, 86 patients (9.6%) died of unrelated causes.Conclusions Cementless porous tantalum TKAs had inferior mid-term performance for aseptic loosening, prompting their discontinuation at our institution.