The effectiveness of neuroplastic interventions on accelerating return to play following anterior cruciate ligament reconstruction: A Systematic Review

Abstract

Introduction: Anterior Cruciate Ligament (ACL) tears are debilitating activity-related orthopaedic injuries that impose a significant burden on athletes and healthcare providers. Rehabilitation following anterior cruciate ligament reconstructions (ACLR) is extensive and challenging, often resulting in high rates of reinjury, contralateral injury, and graft rupture. Research suggests that delaying return-to-play (RTP) may contribute to reducing the risk of reinjury by allowing athletes to develop novel motor strategies. This study investigated whether the integration of motor learning principles into rehabilitation could expedite recovery by targeting neuroplastic adaptations that conventional therapy may not address. Objective: To compare the efficacy of neuroplasticity and motor learning-based interventions against traditional rehabilitation in athletes following ACLR. Inclusion Criteria: This review included studies involving athletes of diverse ages, sexes, and ethnicities, from both contact and non-contact sports, who had undergone ACLR. The interventions focused on neuroplasticity-targeted treatment to enhance knee function compared to traditional ACLR rehabilitation. Neuroplasticity-based interventions included aspects of motor learning, sensory reweighting, visuomotor training, exercises for movement variability, and neurocognitive exercises. Outcomes assessed comprised measures of functional performance, biomechanical parameters, self-reported function, balance, and kinesiophobia. This review included randomised controlled trials (RCT's) and analytical cross-sectional studies. Methods: A three-step search strategy identified relevant published and unpublished studies from 2013 to 2024. Reference lists of identified articles were examined for additional eligible studies. Each study underwent critical appraisal using standardised Joanna Briggs Institute (JBI) tools to ensure methodological rigour. Data on study characteristics and treatment outcomes were extracted using JBI's standardised tools. Due to substantial heterogeneity in study design, participant characteristics, intervention types, and outcome measures, results could not be statistically pooled. Instead, a narrative synthesis was performed to provide a comprehensive overview of findings. vi Results: Six studies reporting outcomes of interest were critically appraised and included: five RCTs and one analytical cross-sectional study. Reported outcomes included biomechanical testing (two studies), functional performance (four studies), static standing balance and dynamic postural sway (two studies), patient-reported function (three studies), and psychological kinesiophobia status (two studies). Findings indicate that neuromuscular training with external focus of attention (EF) cueing may not significantly affect dynamic postural control, but improved biomechanics. Continuous cognitive training (CCT) appeared more effective than EF in enhancing static standing balance and dynamic postural sway. Differential training showed superior functional outcomes compared to visuomotor training, though both improved biomechanics, dynamic balance, and reduced kinesiophobia. A combined plyometric and eccentric training approach demonstrated greater improvements in isokinetic strength and psychological well-being than single-mode training. SpeedCourt training device showed notable gains in jump height and reaction time relative to the control group. Perturbation training offered no additional benefit over traditional rehabilitation focused on strengthening, agility, and secondary prevention. All six included studies assessed outcomes related to return-to-play (RTP) readiness or timelines, using functional, biomechanical, or psychological measures as proxies. However, only one study explicitly reported reinjury incidence, limiting the strength of conclusions regarding the effectiveness of neuroplastic interventions in preventing reinjury. Conclusion: This review reveals a promising link between certain neuroplastic interventions and faster RTP timelines after ACLR. However, no study has directly measured the duration from ACLR to RTP, so conclusive evidence on neuroplastic- focused interventions' impact on RTP acceleration is limited. These findings suggest that rehabilitation programs addressing physical, neurocognitive, and psychological factors critical to safe RTP may yield better outcomes than conventional approaches. Evidence on reinjury prevention remains inconclusive due to the lack of comprehensive outcome measures capturing essential neurocognitive components for motor control. Despite high-quality evidence, the heterogeneity in study designs, intervention types, outcome measures, and population characteristics hinders definitive conclusions.