A Retrospective Analysis of Results and Outcomes after Cadence Total Ankle Arthroplasty Implanted through the End of 2017

Abstract

Category:Ankle; Ankle ArthritisIntroduction/Purpose:Total ankle arthroplasty (TAA) is an increasingly popular operative treatment of ankle arthritis, due to its ability to decrease adjacent joint degeneration and preserve gait mechanics compared to ankle arthrodesis. However, ankle arthroplasty components have a shorter mean longevity then their hip, knee, or shoulder counterparts. The Cadence TAA entered clinical use in 2016 and was designed to address common failure modes of prior systems. We report here on radiographic and clinical outcomes and early complications of the Cadence TAA system at a minimum of 2 years follow-up.Methods:Patients who underwent primary Cadence TAA from 2016 through 2017 by one fellowship-trained foot and ankle surgeon were eligible. Exclusion criteria included prior ipsilateral ankle arthrodesis or arthroplasty and lack of followup. Chart review was performed for eligible patients to identify complications and reoperations. Patients were contacted to obtain Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sport subscores, SF-12 Mental (MCS) and Physical Health (PCS) subscores, and Visual Analog Scale (VAS) pain levels (rated 0-100). Scores were analyzed with 2-sided repeated measures T- tests, with P<0.05 as significant. A second, blinded, fellowship-trained foot and ankle surgeon evaluated followup 5-view radiographs of each ankle to measure range of motion (ROM), alignment, peri-implant osteolysis, and component loosening or subsidence. Subsidence or loosening were defined, respectively, as >2mm or >2⁰ change in position for the tibial component and>5mm or >5⁰ change for the talar component.Results:Sixty patients were included with mean age 64 and mean BMI 32.0. Thirty patients (50%) had concurrent other procedure(s). FAAM-ADL, FAAM-Sports, SF-12 PCS, and VAS pain scores all improved significantly at mean 2.24 years post-op (Table 1). Ten patients (6.7%) had operative complications requiring 15 surgeries (mean 265 days to first reoperation). Three patients (5%) required removal of one or both components, for 2-year implant survival of 95.0%. Two revisions were for infection and one for osteolysis. This produced a mechanical failure rate of 1/60 (1.7%). Radiographic analysis revealed average coronal alignment improved from 7.4⁰ from neutral preoperatively to 2.2⁰ postoperatively. Average ROM was 36.5⁰ total arc of motion.One of 38 (2.6%) had signs of peri-implant osteolysis, with no cases demonstrating loosening or subsidence.Conclusion:Two-year follow-up of the Cadence TAA system demonstrates mechanically stable implants resulting in improved patient function and preserved ankle range of motion. Outcomes compare favorably to those of other TAA systems at 2-year follow-up. Further radiographic and clinical follow-up are needed to evaluate implant longevity and long-term patient functional outcomes.