Early Periprosthetic Tibial Lucency Following Low-Profile Total Ankle Arthroplasty.

Abstract

Background: Most modern total ankle arthroplasty (TAA) implants have low-profile designs that minimize tibial resection and use small pegs or posts for fixation. A number of studies have identified concerning rates of lucencies around the tibial components of these implants. In this study, we evaluated a consecutive series of patients receiving an anterior approach low-profile TAA prosthesis to describe the incidence, characteristics, and progression of tibial component lucencies at short-term (minimum 1-year) follow-up.

Methods: Patients who underwent primary TAA with a modern low-profile TAA tibial implant from 2014 through 2021 were identified from a prospectively collected TAA registry. Poorly defined lucency around the tibial component in all 4 tibial zones, as agreed on by 2 independent reviewers, was considered "global lucency." Intraoperative, 1-year, and 2-year postoperative radiographs were assessed for periprosthetic lucencies. Patients with global lucency at 1 year were compared to the remaining patients.

Results: 554 ankles with a mean 29 ± 19 months of follow-up met inclusion criteria. Twenty-one ankles (3.8%) were revised for tibial loosening. Thirty-six ankles (6.5%) had global tibial lucency at 1 year. Of these, 15 (42%) were eventually revised and the remaining 21 (58%) were doing well clinically at final follow-up. Following multivariable regression, postoperative coronal tibiotalar offset ≥2 degrees (adjusted odds ratio [OR] = 3.60, P = .017), use of the Vantage implant (adjusted OR = 2.84, P = .006), and male sex (adjusted OR = 2.71, P = .016) were predictors of global lucency at 1 year.

Conclusion: At 1 year after anterior approach low-profile TAA, we found a 6.5% incidence of global lucency around the tibial component, suggestive of lack of osseous integration of the prosthesis. Fifty-eight percent of patients with global lucency did not require revision and were doing well clinically at early follow-up. Higher postoperative coronal tibiotalar offset, use of the Vantage implant, and male sex were all significantly associated with development of global lucency.