A 3-arm Randomised Parallel Group Superiority Trial to Investigate the Efficacy of Graded Loading and Return to Sport or Pain Guided Activity, Versus Rest or on Symptom and Disease Severity in Patients With Osgood Schlatter

Osgood Schlatter disease (OSD) affects 10% of adolescents aged 9-15. This makes it the most common knee pain condition in this age group. OSD is considered an overuse injury, common in highly sports active adolescents. It is considered an apophyseal injury of the tibial tuberosity, the site of attachment of the patellar tendon onto the tibia. Repetitive forces exerted on tissues without allowing for recovery can cause pain and/or tissue damage at the site of attachment onto the weak developing apophyseal cartilage which is thought to be a susceptible injury before the apophysis is fully matured. Characteristics such as cartilage swelling, and associated tendon changes (including thickening of the patellar tendon and increased doppler activity) have been documented.

Despite narrative reviews recommending conservative management, there is a complete lack of clinical research evaluating the different recommendations, which range from passive interventions, such as rest/activity limitation, to more active approaches including strength exercises for the lower extremity. We have developed a new progressive return to sport intervention approach which has been piloted in adolescents with OSD. The targeted intervention aims to balance recovery, and graded loading in a guided return to sport paradigm The goal is to help support adolescents manage pain, and guide return to sport & function.

There is a need to test other potential conservative interventions which have yet to be examined in a randomised manner. Multi-arm trials allow more treatments to be assessed than a standard two arm trial. This makes this design simpler, quicker and cheaper than running multiple two arm trials, which will produce contemporaneous results for all treatments. This is relevant in the context of OSD, where none of the conservative recommendations have been evaluated. Despite rest being advocated, it may be possible to allow adolescents to participants to participate in sports to the extent that pain allows (pain guided activity). This may be beneficial, given the social and health consequences of complete withdrawal from sport. We therefore aim to evaluate both the progressive return to sport paradigm and pain guided activity in a 3-armed randomised trial, compared to advice to rest and withdrawal from sports.