Restoring knee function: Physical impairment measures, activity limitations, and patient-reported outcomes after anterior cruciate ligament injury, surgery, and rehabilitation

The overall goal of this work was to identify the physical impairments, activity limitations, and self-reported outcomes after ACL injury, surgery, and rehabilitation. The development of clinical guidelines and performance standards can provide clinicians with practice patterns and benchmarks to optimize patient outcomes and address complications that may arise. By identifying the physical impairments, activity limitations, and self-reported outcomes and responses to injury, surgery, and rehabilitation, we can better predict which impairments and limitations impact patients' knee function and subsequent recovery and implement interventions to facilitate full knee recovery.;Our first experimental study identified a group of individuals with knee function within normal ranges at baseline testing (n=15). Subsequently individuals who did (n=34) or did not (n=52) have a treatment response to perturbation training based on the change scores in the self-report questionnaires and the global knee function question were identified. At baseline testing, responders and nonresponders had lower self-reported outcomes scores than the knee function within normal ranges group. Responders had lower KOS-ADLS and GRS scores than nonresponders. After training, responders and nonresponders had lower self-reported outcomes scores than knee function within normal ranges group. Nonresponders had lower IKDC2000 scores than responders. The involved limb improved in all physical performance measures from baseline to post-training test. Clinicians should implement a battery of tests using performance-based and self-report outcomes to describe patients' function and maximize successful outcomes.;Secondly, we prospectively followed 83 subjects after ACL injury to 12 months after ACL reconstruction. Limb-to-limb symmetries are reduced and normal limb symmetry is restored after perturbation training and returned to similar levels 6 months after reconstruction. Performance-based values on the involved limb and selfreported outcomes are sensitive to change over time and were clinically relevant improvements. Based on the current research, we suggest a rehabilitation program consisting of perturbation training and aggressive quadriceps strength pre-operatively and a systematic criteria-based post-operative program in order to restore normal limb symmetry and maximize functional recovery for patients undergoing ACL reconstruction.;Additionally, of the 83 subjects we followed prospectively, 55 subjects had complete pre-operative data and IKDC2000 scores at 6 months and 52 subjects had complete pre-operative data and IKDC2000 scores at 12 months to examine the relationship of pre-operative quadriceps strength and post-operative self-reported knee function and to investigate how other pre-operative factors may influence this relationship. Pre-operative quadriceps strength can predict IKDC2000 scores 6 months after ACL reconstruction, but did not predict IKDC2000 scores 12 months after reconstruction. These results confirm the importance of good quadriceps strength prior to ACL reconstruction in predicting better knee function after surgery. Factors, such as gender, meniscal injury, pre-operative BMI, and pre-operative quadriceps activation ratio, that are known to influence quadriceps strength and self-reported outcomes do not influence the relationship between pre-operative quadriceps strength and post-operative IKDC2000 scores.;Our last experimental study was to determine if one-legged hop tests conducted pre-operatively and 6 months after surgery would predict self-reported knee function 1 year after ACL reconstruction. Single hop, cross-over hop, triple hop, and 6-m timed hop limb symmetry indexes 6 months after ACL reconstruction significantly predicted self-reported knee function within normal ranges 1 year after surgery. The 6-meter timed hop was the strongest individual predictor of self-reported knee function and had the highest discriminative accuracy. Pre-operative one-legged hop test did not predict self-reported knee function within normal ranges 1 year after ACL reconstruction. A comprehensive test battery may be needed to increase the sensitivity in predicting self-reported knee function.;A systematic review was performed to establish performance standards for the single hop for distance after ACL reconstruction. Thirty-two articles were included in the final analysis. Individuals had lower single hop symmetry indexes and hop distances early after surgery that improved up to 13 months after ACL reconstruction. Individuals with patella tendon-bone autografts had lower hop symmetry index and large limb-to-limb differences than other graft types between 3 and 7 months after surgery. Clinicians can use these performance-based standards to guide their expectations after ACL reconstruction and direct their interventions if a patient is not meeting pre-determined criteria to progress their rehabilitation.;Two systematic reviews were performed to develop evidence-based clinical practice guidelines for patients with musculoskeletal impairments related to knee ligamentous injuries, and knee meniscal and chondral injuries based on musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). MEDLINE, CINAHL, and the Cochrane Database of Systematic Reviews (1966 through January 2009) were systematically reviewed for any relevant articles related to classification, outcome measures, and intervention strategies for ligament injuries and instabilities of the knee, and meniscal and chondral injuries of the knee. When relevant articles were identified their reference lists were hand-searched in an attempt to identify other articles that might have contributed to the outcome of clinical practice guidelines. Recommendations were made regarding clinical course, risk factors, diagnosis and classification, differential diagnosis, examination, and interventions. Individual clinical research articles were graded and the overall strength of the evidence supporting the recommendations made in these guidelines were also graded.