Complications following anterior cruciate ligament reconstruction

Sammanfattning: Background: Venous thromboembolism (VTE) and septic arthritis (SA) are two rare complications following anterior cruciate ligament reconstruction (ACLR). Due to their rare incidence, risk factors and outcome are difficult to analyse and the aims of this thesis are to improve knowledge in this area. Methods: All studies are register based. The study populations have been extracted from the Swedish Knee Ligament Register (SKLR) and have been linked to data from registers at the National Board of Health and Welfare to establish the incidence. A nationwide medical record review was performed to verify the events of SA. Risk factor analyses were made with data from both register sources. The subjective outcome was initially investigated with a non-response analysis of the SKLR, including a separate non-response questionnaire. Secondly, the subjective outcome for patients with VTE and SA was analysed based on data extracted from the SKLR. Finally, the risk of revision ACLR was investigated among patients with SA after primary ACLR. Results: The incidence of VTE and SA after ACLR was 0.4% and 1.1% respectively. The analyses of risk factors revealed that older age at surgery is the only independent risk factor for VTE after ACLR; while male sex, longer operating time, use of clindamycin instead of cloxacillin and a hamstring tendon autograft instead of a patellar tendon autograft are independent risk factors for SA after ACLR. The response rate for the subjective outcome is higher among female and older patients, with small differences in the outcome scores between respondents and non-respondents. The patients with SA report an inferior subjective outcome on all follow-up occasions and a poorer long-term outcome. The risk of revision ACLR is doubled among patients with SA after primary ACLR compared with patients without SA. Conclusion: This thesis demonstrates that an analysis of rare complications is possible using register data. Novel findings relating to risk factors for the studied complications, as well as novel findings on outcome data for patients with SA after primary ACLR, are presented. Knowledge about the risk factors can be used to modify and optimize perioperative routines in order to decrease the risk of serious complications and revision surgery, and to increase the subjective outcome after ACLR.