A Population-Based Nationwide Study of Cruciate Ligament Injury in Sweden, 2001-2009

Background: A few national cruciate ligament (CL) registers have been initiated with operative surveillance and outcome monitoring. No nationwide study describing CL injury has ever been done. Purpose: To study the incidence and characteristics of patients diagnosed with cruciate ligament injury in Sweden. Study Design: Descriptive epidemiology study. Methods: Data for all patients with a diagnosed CL injury between 2001 and 2009 were identified from the National Swedish Patient Register. Risk analysis and specific incidences were calculated according to age, sex, geographic region, and surgery. Results: A total number of 56,659 patients with CL injury were included in the study, and the overall incidence of CL injury in Sweden was 78 per 100,000 persons. Sixty percent of the patients were male. The mean age was 32 years (range, 1-98 years), and 50% of the cohort was younger than 30 years. There was an increased rate of injury among female patients younger than 20 years as compared with male patients in that age group. Among patients with CL injury, 36% underwent reconstructive surgery, with one-third of these performed within 1 year after injury. Among patients who underwent surgery, 59% were male; the mean age was 27 years (range, 5-89 years). Conclusion: This study defines the incidence of CL injury and also demonstrates sex differences in which men were more likely to sustain a CL injury, although female patients were injured at an earlier age. The findings in this study corroborate the results from recent surgical registers. Clinical Relevance: No data have hitherto been published including all patients with CL injury, treated both surgically and nonsurgically. Such baseline epidemiologic data are crucial to be able to validate and judge the generalizability of results from procedure registers and clinical studies.