Association of Preoperative Coronal Plane Deformity With Postoperative Tibial Bone–Prosthesis Interface Lucency in the Cadence Total Ankle

Background: Minimal resection total ankle arthroplasty (TAA) has been linked to an increased incidence of tibial component lucency in large preoperative coronal plane deformity. Lucency has been linked to implant loosening. Because radiographic lucency may reflect implant micromotion, lack of bony ingrowth and/or early component loosening, we analyzed a series of TAA cases with varying degrees of preoperative coronal deformity. Our primary aim was to determine if larger preoperative tibiotalar angles were associated with increased postoperative tibial component lucency in the Cadence TAA system. Methods: A retrospective review of a single surgeon’s TAA procedures using the Cadence prosthesis was conducted. Patients aged ≥18 years who underwent Cadence TAA from January 1, 2018, to December 31, 2023, were included; those with <12 months’ follow-up or poor-quality radiographs were excluded. Lucency was defined as a radiolucent line at the interface between the tibia and the tibial component that was greater than 0.5 mm at any point. The patient’s final follow-up radiograph was used for this analysis. Pre- and postoperative tibiotalar alignment was recorded. Results: Fifty-five ankles were examined. The average follow-up duration was 29.8 months. Sixteen patients (29%) had no deformity. Twenty-seven patients (49%) had less than 15 degrees of angulation and 12 patients (22%) had more than 15 degrees of angulation. Postoperatively, all ankles were corrected to within 3.7 degrees of a coronal tibiotalar angle of 90 degrees. Comparisons among the 3 groups with χ 2 tests and analyses of variance revealed no significant differences in tibial interface lucency across any zone ( P > .05). Conclusion: Aseptic loosening in TAAs, indicated by peri-implant lucency, is a recognized mode of failure. Recent studies suggest that preoperative coronal tibiotalar angles greater than 15 degrees increase the risk of failure when using minimal resection TAA. In this short-term, single-surgeon cohort, there were no differences in peri-implant lucency between groups. Findings should be interpreted cautiously, given the limited follow-up and statistical power. Level of Evidence: Level IV, retrospective analysis.