JOA - 2026-06-01 - Journal Article; Comparative Study
Outcomes after Contemporary Cementless Versus Cemented Primary Total Knee Arthroplasty at Five Years: Some Subtle Differences.
Salmons HI, Seward MW, Messer CJ, Bedard NA, Taunton MJ, Perry KI, Pagnano MW, Trousdale RT, Wyles CC
Topics
Key Takeaway
Cementless TKA with porous titanium tibial components achieved 97% 5-year revision-free survivorship equivalent to cemented TKA, while beaded CoCr cementless tibias had a 3x higher revision hazard ratio driven by early loosening within 1 year.
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Summary
This study compared 5-year implant survivorship between contemporary cementless and cemented primary TKA using an institutional total joint registry of 3,763 knees from 2016–2023. Overall 5-year revision-free survivorship was 92% cementless vs. 97% cemented (HR=3, P<0.05), but when CoCr cementless tibias were excluded, porous Ti cementless survivorship matched cemented at 97%. All four cementless loosening failures involved CoCr tibias and occurred within 1 year, while all five cemented loosening failures occurred between 2–5 years.
Key Limitation
Mean follow-up of only 3 years is insufficient to detect late aseptic loosening differences between Ti cementless and cemented constructs, which typically manifest beyond 5–10 years.
Original Abstract
INTRODUCTION
Cementless total knee arthroplasty (TKA) has regained interest due to the potential long-term survivorship and ease of use. However, data on contemporary cementless TKA remain limited. We investigated implant survivorship and outcomes following contemporary cementless versus cemented TKA.
METHODS
We identified 3,763 primary TKAs for osteoarthritis from January 1, 2016, to December 31, 2023, using our institutional total joint registry (TJR). There were 598 cementless and 3,165 cemented TKAs. Cementless tibial components included porous titanium (Ti) in 509 knees and beaded cobalt-chromium (CoCr) in 89 knees. We excluded all-polyethylene tibias, stemmed tibias, and revision constructs. The mean age was 68 years (range, 28 to 96), the mean body mass index (BMI) was 32 (range, 17 to 65), and 56% were women. The cementless group was younger and contained more men (P < 0.05). Kaplan-Meier and Cox regression analyses adjusted for age, sex, body mass index, and surgical year were performed. The mean follow-up was three years (range, two to eight years).
RESULTS
There were 61 revisions (1.6%): 11 (1.8%) in the cementless and 50 (1.6%) in the cemented group. Revisions were primarily for infection (N = 31) and aseptic loosening (N = nine). All four loosening cases after cementless TKA involved CoCr tibias within 1 year. All five cemented TKA loosening cases occurred between two and five years. The 5-year revision-free survivorship was 92% in cementless and 97% in cemented TKAs (hazard ratio (HR) = 3; P < 0.05). Excluding CoCr tibias, Ti cementless survivorship was 97%. The 5-year survivorships free from revision for infection were 98% in cementless and 99% in cemented TKAs (hazard ratio = 3; P < 0.05). There were no differences in periprosthetic fracture risk observed (P = 0.5).
CONCLUSIONS
We identified subtle differences between contemporary cementless and cemented primary TKA mid-term outcomes. We found a slightly higher infection risk in the cementless group, excellent durability of Ti cementless and cemented tibias, and a higher loosening risk with CoCr cementless tibias.
LEVEL OF EVIDENCE
III.