Which Tibial Tray Design Achieves Maximum Coverage and Ideal Rotation: Anatomic, Symmetric, or Asymmetric? An MRI-based study

Better Implant Positioning and Clinical Outcomes With a Morphometric Unicompartmental Knee Arthroplasty. Results of a Retrospective, Matched-Controlled Study

“…An optimally implanted UKA tibial component would be one that can flush with all edges of the tibia. This is often not possible, partly because current traditional tibial components may not be of ideal shape and often require a compromise between optimal rotation and bone coverage [18,20]. Fitzpatrick et al [19] and Servien et al [24] reported a better theoretical positioning with an optimized rotation-coverage ratio using a morphometric tibial implant in UKA.…”

“…Conversely, tibial tray subsidence and early loosening are increased when cortical support is insufficient and tibial surface undercovered [16,17]. Furthermore, coronal plane position error may lead to abnormal contact stress and MCL tension [18]. Historical UKA designs did not aim at reproducing tibial plateau morphometry [19] but were rather built as simple symmetric shape.…”

“…Historical UKA designs did not aim at reproducing tibial plateau morphometry [19] but were rather built as simple symmetric shape. Consecutively, compromises in size and rotation positioning might have to be realized intraoperatively [18,20]. Following the good results obtained in TKA with morphometric and lateralized tibial implants, new tibial trays for UKA have been developed.…”

Early Clinical and Radiological outcomes of the New Anatomic Knee System : Minimum 3-year Follow-up.

“…Second, the medioposterior area of the tibial component is asymmetrical in shape and slightly longer than the lateral measurements, giving it a more anatomical shape [14,[17][18][19]. Hence, it can facilitate proper rotation with unprecedented surface coverage [13][14][15]20]. Third, the femoral components are of two types, standard and narrow.…”

Morphometric Tibial Implant Decreases Posterior Overhang Rate and Improves Clinical Outcomes: Results of a Prospective, Matched Controlled Study

“…Conversely, a too small tibial component is at risk of early loosening due to insufficient cortical support [14]. With a symmetrical tibial tray, due to the anatomical asymmetry of the tibial plateau between the medial and lateral compartments, compromises in size and rotational positioning might have to be done intra-operatively [15][16]. To optimize rotational-coverage ratios and limit the potential conflicts with the soft-tissues, new designs of tibial implants have been developed using large anatomical data-bases and specific software simulating bone cuts.…”