Reframing Fixation Strategy in Total Knee Arthroplasty With Tibial Bone Density as a Central Criterion
Yoshinori Mikashima, Ken OkazakiBackground:
Cementless total knee arthroplasty (TKA) has gained renewed interest with advances in implant design, porous coatings, and surgical accuracy. However, early aseptic loosening continues to be reported, particularly in patients with reduced tibial bone mineral density (BMD). Cemented TKA also demonstrates loosening related to thin or insufficient cement mantles, especially in younger, high-body mass index, or highly active patients. Despite advances in available fixation methods, clear and reproducible criteria to guide fixation selection have yet to be established.
Methods:
A narrative review was conducted to summarize recent evidence regarding fixation strategy in TKA with a focus on tibial BMD. A PubMed literature search identified studies published between 2016 and 2026 using terms related to fixation methods (cementless and cemented TKA), tibial bone density, loosening mechanisms (migration, subsidence, early failure), and cementing techniques (cement mantle thickness and cement penetration). The initial search yielded 289 articles, of which 84 studies relevant to bone density, fixation stability, implant design, and loosening mechanisms were included.
Results:
Large database studies consistently reported higher early aseptic loosening rates in cementless TKA, particularly in patients with low tibial BMD. Radiostereometric analyses demonstrated increased migration of cementless tibial components in low-density bone. In cemented TKA, inadequate cement penetration and thin or nonuniform cement mantles were strongly associated with tibial loosening. Recent computed tomography–based techniques—including hydroxyapatite-equivalent BMD and dual-energy computed tomography volumetric BMD—show strong correlations with trabecular bone strength and provide practical thresholds for fixation selection.
Conclusion:
Based on the results of all the papers reviewed, tibial BMD values are important and do influence the loosening rate of tibial components. Those patients with tibial BMD values below 46.4 HA/cm 3 support the use of cemented fixation, while those exceeding 78.4 HA/cm 3 seem to be better candidates for cementless fixation due to limited cement penetration.