A study published in The Lancet, “Opioid use, postoperative complications, and implant survival after unicompartmental versus total knee replacement: a population-based network study,” showed unicompartmental knee replacement (UKR) patients used less opioids postoperatively than those who had total knee arthroplasty (TKR). The same study showed that while risk of venous thromboembolism was also lower, the risk of revision was increased. Full study.