Objective: Shared decision-making (SDM) is a strongly endorsed approach by which patients and clinicians work together to formulate a sensible care plan. The present study was undertaken to conduct a systematic review of SDM trials in patients considering knee arthroplasty (KA) to characterize how SDM was supported and the impact on care received. Methods: We searched multiple bibliographic databases from inception to December 31, 2019. A pair of reviewers working independently selected studies for inclusion, extracted data, and evaluated each trial’s risk of bias. Results: We found 6 eligible randomized trials (4 included KA and hip arthroplasty), all of which tested the same proprietary decision aid (DA) (Treatment Choices for Hip or Knee Osteoarthritis), with some adding other materials to support SDM. These trials, all of which had moderate-to-high risk of bias, focused on assessing the effect of the DA on patient knowledge about the options while not explicitly supporting other aspects of SDM, such as choice awareness, deliberation, or decision-making. One trial found an increase in the number of African American patients undergoing KA in the 12 months following the intervention. No other trials found that SDM impacts clinical outcomes. Conclusion: Evidence for SDM in patients considering KA is mostly limited to a single DA. While use of this DA improves patient knowledge about their treatment options, this tool has not been shown to promote SDM, impact treatment decisions, or satisfaction with care. Future work should seek to support SDM directly and assess effects on treatment decisions, functional outcomes, and satisfaction.