Knee function, movement pattern and knee osteoarthritis in males 14-16 years after an anterior cruciate ligament injury

Abstract: The overall aim of this work was to study knee function movement pattern and knee osteoarthritis in males 14-16 years after anterior cruciate ligament (ACL) injury. In the first study, 154 male subjects with a 14-year-old ACL injury were investigated. Self-reported knee function and radiographic signs of osteoarthritis were assessed. Most of the subjects (122/154) underwent knee radiographs, 78% of which showed radiographic changes. The prevalence of tibio-femoral knee osteoarthritis (OA) was 41%. Fourteen years after the ACL injury the self-reported knee function was worse than in healthy subjects. In the second and third studies 12 male subjects with a 16-year-old ACL injury and 12 matched healthy references were investigated. In Study II, the kinetics and kinematics of three functional tests: gait, step activity and cross-over hop, of the 12 ACL-injured subjects (a geographically determined subgroup from Study 1) and the 12 matched reference were compared. The self-reported knee functions of the two groups were also compared. No detectable differences were found in the kinetics and kinematics of the ACL-injured subjects and their matched reference. The self-reported knee function among ACL-injured subjects was, however, worse than that among non-injured subjects. In the third study, an intervention programme consisting of knee-specific exercises, once a week for twelve weeks, was applied to the subjects with an ACL injury. After twelve weeks of training, both under supervision and at home, motion analysis of the injured subjects showed results closer to those of the healthy controls, and self-reported knee function had improved. The fourth study was carried out to determine the reliability and validity of the functional performance tests: gait, knee bending, step activity, cross-over hop and one-leg hop. Four physiotherapists were used as observers. The physiotherapists assessed the knee function of the subjects with an ACL injury before and after the training period using video sequences. The reliability between the physiotherapists was relatively good and the validity of the functional performance tests when compared with the motion analysis data was acceptable. Based on the results presented in this thesis, it can be concluded that the prevalence of tibio-femoral knee osteoarthritis, 14 years after an ACL injury, is high, and that self-reported knee function is affected, despite the long time since injury. No differences in motion analysis results could be seen between injured subjects and references; however a type II error could not be ruled out. Knee-specific training for twelve weeks decreased knee stiffness and improved self-reported knee function. The moderate to good reliability and the acceptable validity found indicate that the presence of knee stiffness in subjects with an ACL injury can be determined by visual observation of more demanding functional tests.