Association of Component Sizing on Total Ankle Arthroplasty Survivorship.

BACKGROUND

Component sizing and alignment are critical to total ankle arthroplasty (TAA) longevity, yet the relationship between talar downsizing, polyethylene thickness, and revision risk remains unclear.

PURPOSE: This retrospective cohort study evaluated whether talar downsizing improves survivorship and examined secondary associations between polyethylene thickness, coronal alignment, and revision.

STUDY

DESIGN

Level III Retrospective Study

METHODS

A retrospective cohort study with 173 TAA procedures was performed. Variables included talar downsizing status, tibial and talar component sizes, initial polyethylene thickness, and comorbidities. Primary outcomes were revision or polyethylene exchange. Logistic regression assessed the relationship between downsizing, polyethylene size, and revision risk; correlation analysis examined polyethylene size versus preoperative tibiotalar angle.

RESULTS

Talar downsizing was performed in 115 of 173 ankles (66.5%). Patients with a downsized talar component showed a lower, though nonsignificant, likelihood of revision (OR 0.66; p = 0.36). Smaller polyethylene components (≤7 mm, n = 12) were associated with significantly higher reoperation rates than components ≥8 mm (33.3% vs 19.3%; OR = 3.05; p = 0.04) Mean preoperative coronal alignment was 0.98° valgus ± 8.9° (95% CI -0.35 to 2.31), with no correlation between polyethylene (PE) thickness and deformity (r = -0.01; p = 0.90). Hindfoot fusion was not statistically significantly associated with revision risk (p = 0.07). Implant survivorship was 86.9% at a mean clinical follow-up duration of 4.1 ± 2.2 years (range, 1.0-9.3 years).

CONCLUSION

Talar component downsizing was not significantly associated with revision risk in this cohort. While downsizing may offer potential biomechanical benefits related to edge-loading and alignment, further investigation is needed to determine whether these factors translate to improved clinical outcomes.