Getting Kids With Osgood Schlatter Back to Performing Without Pain

The goal of this trial is to compare graded return to sport, or pain guided activity to rest in youth with Osgood Schlatter. The main objectives are:

- to assess the graded return to sport, or pain guided activity on symptoms (pain and function) at six months compared to rest

The secondary objectives are to assess the impact of progressive return to sport or pain guided activity on:

* Muscle strength and performance
* Anterior knee pain provocation
* Sports participation
* Physical activity

The exploratory objectives are to assess the impact of progressive return to sport on ultrasound imaging characteristics of OSD.

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.

Eligibility Criteria:
Inclusion Criteria:

- Children/adolescents (male and female) aged 8-16 years

* Diagnosis of OSD based on clinical examination including localised pain at the tibial tuberosity (the insertion of the patellar tendon onto the shin) that increases by palpation, and pain during resisted isometric knee extension.
* Ability to understand and the willingness to provide consent

Exclusion Criteria:

* Any other diagnosable knee pathology, patellar instability, and patellofemoral instability.
* Previous knee surgery
* Habitual patella subluxation
* Clinical suspicion of meniscal lesion
* Previous neurologic, musculoskeletal or mental illnesses
* Other chronic conditions that may affect the involved musculoloskeletal/connective tissues and treatment (autoimmune, metabolic disorders, diabetes, etc.)
* Lack of ability to cooperate