Why knee ligament registries are important…

National quality registries have been used in severalmedical specialties to improve health care in Scandinavia[1, 3–6]. Due to the inferior clinical results associated withsome hip prosthesis designs in the early 1980s [6], thenationwide Hip Arthroplasty Register (NAR) was estab-lished in Sweden in 1979 and in Norway in 1987 withimplant revision as the main end point [1]. The purpose isthe early detection of inferior results caused by implants,cements or surgical techniques [1, 3, 6]. In 1994, theNorwegian registry was expanded to include all jointreplacements [3]. In 1995, two studies were published [1,3] describing the detection of inferior implants at an earlystage, a nding only possible through registry studies.NAR is based on a simple reporting system (approxi-mately 1 min to complete a single-paged registrationform), and the hospitals are provided with continuousfeedback from the registry [1, 2]. These two factors arebelieved to explain why the compliance rate of nearly100% has not declined during 20 years of operation [1, 2].Immediately after each operation, the surgeon completesthe registration form, which is mailed to the NAR ofce.Patient identication and the different procedures, includ-ing the type of implant and cement used, are specied onthe registration form. Feedback is given as annual nationalreports. In addition, each hospital receives a report on itsown activities and results, which can be compared to thenational average. A wide range of studies have been pub-lished based on the NAR database [1, 3, 6].In contrast to joint replacement surgery, where nationalregistries have been established in Norway, Sweden(1979), Finland (1980), Denmark (1995), Australia (1999),New Zealand (1999), Canada (2000), Romania (2001), andEngland and Wales (2003), no prospective surveillancesystem has existed for monitoring the outcome of kneeligament surgery in a predened population. Evidence fromthe Scandinavian joint replacement registries indicates thata national knee ligament registry could be highly bene-cial. First, treatment outcome can be improved throughfeedback to the hospitals and surgeons from the registries.Second, there are still several unresolved issues related tocruciate ligament surgery and postoperative rehabilitationmethods. Some of these can and should be addressed byconducting properly designed randomized controlled trials(RCTs). However, because of practical, nancial or otherrestraints, such studies are often not possible. Also, somequestions can only be answered by large cohort studies.This can include the detection of procedures and devicesthat result in premature failure. Third, a large cohort studycan be used to identify prognostic factors associatedwith good and poor outcomes. Data from the NorwegianRegistry show a very high compliance rate [2] and also thatthis type of registry can be run in a country with 5 millioninhabitants for approximately US$ 100,000 a year excludingthe local costs.With this background, the Norwegian Knee LigamentRegistry (NKLR) was started in June 2004, followed by theDanish and Swedish registries in 2005. In this edition of theKSSTA journal, Martin Lind and co-workers report from