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Is neuromuscular control during valgus knee loading associated with changes in tibial cartilage morphology following ACL reconstruction?
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Thursday 22 October Papers / Journal of Science and Medicine in Sport 19S (2015) e2–e32
Award Finalist
Discussion: Biomechanically-informed injury prevention training is successful in reducing non-contact ACL injury rates, while also improving and/or maintaining athletic performance. These results provide valuable information to coaches and medical staff interested in implementing effective injury prevention training protocols in time-poor competitive season schedules without sacrificing athletic performance.
Return to sport explains variability in quality of life 5 to 20 years following anterior cruciate ligament reconstruction
http://dx.doi.org/10.1016/j.jsams.2015.12.442
S. Filbay 1,∗ , I. Ackerman 2 , T. Russell 1 , K. Crossley 1,3
Award Finalist 60 Is neuromuscular control during valgus knee loading associated with changes in tibial cartilage morphology following ACL reconstruction? L. Jenkins ∗ , K. Fortin, X. Wang, A. Bryant Centre For Exercise Health and Sports Medicine, University of Melbourne, Australia Background: Patients who have undergone anterior cruciate ligament reconstruction (ACLR) exhibit altered lower limb biomechanics, particularly during high demand sporting activities. Over time, altered loading patterns are thought to contribute to a loss of knee joint cartilage in the ACLR involved knee – a predisposing factor in the development of debilitating knee joint osteoarthritis (OA). The aim of this study was to identify relationships between tibial acceleration transients during multidirectional hop landing tasks, and medial and lateral tibial cartilage morphology. Methods: 55 individuals (36 males, 19 females) having undergone ACLR 2-3 years prior, using the combined semitendinosis/gracilis tendon graft, volunteered to participate in the study. All subjects performed a series of single-limb (involved) ipsilateral hop tasks – forward hop, and 45◦ hop from initial standing position to left and right to create valgus knee stress – at 75% of lower limb length with a 20 g triaxial accelerometer fixed to the proximal tibia. ACLR knees were scanned using MRI in order to quantify medial and lateral tibial cartilage volume. Pearson’s product moment correlations were used to establish the strength of associations between biomechanical and knee cartilage measures. Results: A significant (p < 0.05) negative correlation was identified between time to stabilise in the medio-lateral plane; i.e. time for medio-lateral acceleration transients to remain stable for >1 s at 0.25 g, and normalised medial tibia cartilage volume (r = −0.291). Discussion: The degree of neuromuscular control when landing in knee valgus is a determinant of medial cartilage volume at 2–3 years following ACLR. Specifically, ACLR subjects with lower cartilage volume took more time to stabilise the knee on landing from dynamic hop. Poor neuromuscular control in high demand tasks may influence cartilage health and the development of knee OA in the years following ACLR. Hence, prescription of dynamic neuromuscular training and the use of hop tasks in rehabilitation exercises post ACLR may enhance knee joint health in the longer term. http://dx.doi.org/10.1016/j.jsams.2015.12.443
61
1 School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Australia 2 Melbourne EpiCentre, The University of Melbourne, Melbourne, Australia 3 The College of Science, Health and Engineering, La Trobe University, Melbourne, Australia
Introduction: Many individuals experience persistent knee symptoms, impairments in quality of life (QOL) and do not return to competitive sport 5–20 years following anterior cruciate ligament reconstruction (ACLR). However, specific factors associated with QOL in these individuals are poorly understood. This study will be the first to (i) describe QOL in people with knee symptoms ≥5 years following ACLR, and (ii) identify factors associated with QOL in these individuals. Methods: We analysed baseline data from a longitudinal study of people who had undergone ACLR 5–20 years previously. All participants experienced knee pain, stiffness or activity limitations and were recruited from records of four experienced surgeons and community advertisements. Participants completed the ACLQOL questionnaire, Knee injury and Osteoarthritis Outcome Score (KOOS), the AQoL-8D and a demographics questionnaire. Multivariable linear regression was performed to identify factors explaining variability in QOL outcomes. Direct acyclic diagrams were used to select variables and covariates for use in regression analyses. Models were adjusted for potential confounders. Results: 162 participants with a mean age of 38 ± 9 years completed the questionnaires on average 9 ± 4 years following ACLR. Over half of participants were overweight (34%) or obese (22%), 32% did not return to sport after ACLR, 28% returned to a lower level and 39% returned to the same or higher level of sport. Of those who ceased sport, 79% reported that this was due to their knee. Average KOOS-QOL (55 ± 20) and ACL-QOL scores (57 ± 21) were considerably lower than population norms and data from previous ACLR studies. AQoL-8D values (0.80 ± 0.14) were slightly impaired compared to Australian population norms, exceeding the minimal important difference for people aged 49–55 years. Multivariate analyses revealed that returning to sport at the same or higher level compared with not returning to sport at all, explained the greatest amount of variability in QOL outcomes. Not returning to sport after ACLR was associated with poorer KOOS-QOL (ˇ = .27, p = 0.003), ACL-QOL (ˇ = .47, p < 0.001) and AQoL-8D (ˇ = .23, p = 0.01) scores. Variance in QOL scores was partially explained by subsequent surgery, BMI and bilateral ACLR. All variables were still associated with QOL scores after adjusting for potential confounders (KOOSpain, age and sex). Discussion: QOL is impaired in people with knee difficulties 5–20 years after ACLR. Individuals who do not return to sport after ACLR may be at heightened risk of poor long-term QOL, and could benefit from management strategies aimed at optimising QOL and facilitating a physically active lifestyle. http://dx.doi.org/10.1016/j.jsams.2015.12.444
Thursday 22 October Papers / Journal of Science and Medicine in Sport 19S (2015) e2–e32
Award Finalist
Discussion: Biomechanically-informed injury prevention training is successful in reducing non-contact ACL injury rates, while also improving and/or maintaining athletic performance. These results provide valuable information to coaches and medical staff interested in implementing effective injury prevention training protocols in time-poor competitive season schedules without sacrificing athletic performance.
Return to sport explains variability in quality of life 5 to 20 years following anterior cruciate ligament reconstruction
http://dx.doi.org/10.1016/j.jsams.2015.12.442
S. Filbay 1,∗ , I. Ackerman 2 , T. Russell 1 , K. Crossley 1,3
Award Finalist 60 Is neuromuscular control during valgus knee loading associated with changes in tibial cartilage morphology following ACL reconstruction? L. Jenkins ∗ , K. Fortin, X. Wang, A. Bryant Centre For Exercise Health and Sports Medicine, University of Melbourne, Australia Background: Patients who have undergone anterior cruciate ligament reconstruction (ACLR) exhibit altered lower limb biomechanics, particularly during high demand sporting activities. Over time, altered loading patterns are thought to contribute to a loss of knee joint cartilage in the ACLR involved knee – a predisposing factor in the development of debilitating knee joint osteoarthritis (OA). The aim of this study was to identify relationships between tibial acceleration transients during multidirectional hop landing tasks, and medial and lateral tibial cartilage morphology. Methods: 55 individuals (36 males, 19 females) having undergone ACLR 2-3 years prior, using the combined semitendinosis/gracilis tendon graft, volunteered to participate in the study. All subjects performed a series of single-limb (involved) ipsilateral hop tasks – forward hop, and 45◦ hop from initial standing position to left and right to create valgus knee stress – at 75% of lower limb length with a 20 g triaxial accelerometer fixed to the proximal tibia. ACLR knees were scanned using MRI in order to quantify medial and lateral tibial cartilage volume. Pearson’s product moment correlations were used to establish the strength of associations between biomechanical and knee cartilage measures. Results: A significant (p < 0.05) negative correlation was identified between time to stabilise in the medio-lateral plane; i.e. time for medio-lateral acceleration transients to remain stable for >1 s at 0.25 g, and normalised medial tibia cartilage volume (r = −0.291). Discussion: The degree of neuromuscular control when landing in knee valgus is a determinant of medial cartilage volume at 2–3 years following ACLR. Specifically, ACLR subjects with lower cartilage volume took more time to stabilise the knee on landing from dynamic hop. Poor neuromuscular control in high demand tasks may influence cartilage health and the development of knee OA in the years following ACLR. Hence, prescription of dynamic neuromuscular training and the use of hop tasks in rehabilitation exercises post ACLR may enhance knee joint health in the longer term. http://dx.doi.org/10.1016/j.jsams.2015.12.443
61
1 School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Australia 2 Melbourne EpiCentre, The University of Melbourne, Melbourne, Australia 3 The College of Science, Health and Engineering, La Trobe University, Melbourne, Australia
Introduction: Many individuals experience persistent knee symptoms, impairments in quality of life (QOL) and do not return to competitive sport 5–20 years following anterior cruciate ligament reconstruction (ACLR). However, specific factors associated with QOL in these individuals are poorly understood. This study will be the first to (i) describe QOL in people with knee symptoms ≥5 years following ACLR, and (ii) identify factors associated with QOL in these individuals. Methods: We analysed baseline data from a longitudinal study of people who had undergone ACLR 5–20 years previously. All participants experienced knee pain, stiffness or activity limitations and were recruited from records of four experienced surgeons and community advertisements. Participants completed the ACLQOL questionnaire, Knee injury and Osteoarthritis Outcome Score (KOOS), the AQoL-8D and a demographics questionnaire. Multivariable linear regression was performed to identify factors explaining variability in QOL outcomes. Direct acyclic diagrams were used to select variables and covariates for use in regression analyses. Models were adjusted for potential confounders. Results: 162 participants with a mean age of 38 ± 9 years completed the questionnaires on average 9 ± 4 years following ACLR. Over half of participants were overweight (34%) or obese (22%), 32% did not return to sport after ACLR, 28% returned to a lower level and 39% returned to the same or higher level of sport. Of those who ceased sport, 79% reported that this was due to their knee. Average KOOS-QOL (55 ± 20) and ACL-QOL scores (57 ± 21) were considerably lower than population norms and data from previous ACLR studies. AQoL-8D values (0.80 ± 0.14) were slightly impaired compared to Australian population norms, exceeding the minimal important difference for people aged 49–55 years. Multivariate analyses revealed that returning to sport at the same or higher level compared with not returning to sport at all, explained the greatest amount of variability in QOL outcomes. Not returning to sport after ACLR was associated with poorer KOOS-QOL (ˇ = .27, p = 0.003), ACL-QOL (ˇ = .47, p < 0.001) and AQoL-8D (ˇ = .23, p = 0.01) scores. Variance in QOL scores was partially explained by subsequent surgery, BMI and bilateral ACLR. All variables were still associated with QOL scores after adjusting for potential confounders (KOOSpain, age and sex). Discussion: QOL is impaired in people with knee difficulties 5–20 years after ACLR. Individuals who do not return to sport after ACLR may be at heightened risk of poor long-term QOL, and could benefit from management strategies aimed at optimising QOL and facilitating a physically active lifestyle. http://dx.doi.org/10.1016/j.jsams.2015.12.444