The Norwegian and Swedish National Knee Ligament Registries

The NKLR was initiated in 2004 and the SNKLR in 2005 [17]. Data are collected prospectively and the estimated coverage of primary ACL reconstructions in the registries is close to 90% [18] in Sweden and 86% [19] in Norway. Surgical data, including primary and revision ACL reconstruction, are registered by the treating surgeon. Patients are identified by their unique social security number [20]. Follow-up using the Knee injury and Osteoarthritis Outcome Score (KOOS) is carried out by both registries. This is done preoperatively and, in Norway 2-, 5-, and 10-year postoperatively, while, in Sweden, follow-up takes place 1-, 2-, 5-, and 10-year postoperatively [17, 18, 21].