Owen AR, Markos JR, Mabry TM, et al. - This study was sought to assess whether and how contemporary primary total knee arthroplasty is durable in patients diagnosed with ankylosing spondylitis. Between 2000 – 2016, researchers designed an institutional total joint registry to distinguish 19 patients (28 knees) with a diagnosis of ankylosing spondylitis (AS) treated with primary total knee arthroplasty (the mean age at total knee arthroplasty (TKA) was 68 years, and 84% of patients were male and the mean follow up was 6 years). Implant survivorship, clinical outcomes, and complications were the outcome measures. The data showed that in patients with AS, primary TKAs resulted in significant improvement in clinical outcomes with excellent 10-year implant survivorship. The range of motion was restored postoperatively, although two MUAs were required. These outcomes imply contemporary primary TKA can achieve durable and reliable results in patients with axial skeletal disease resulting from AS.