ACTIVE KNEECAPs! tArgeted effeCTIVE treatments for adolescent KNEECAP pain

The aim of this RCT is to compare the effectiveness and cost-effectiveness of foot orthoses or targeted physiotherapy, combined with advice, with advice alone, in adolescents with patellofemoral pain (PFP). Participants will be randomised to one of three intervention arms: (1) Foot orthoses + advice (2) Targeted physiotherapy + advice; or (3) Advice (control). Arm 1: Foot orthoses + Advice The foot orthoses intervention aims to provide adolescents with a simple device that can be worn in their everyday shoes, with minimal additional time and effort required by them. Participants will receive prefabricated contoured foot orthoses from a commercially available range (Vasyli Medical, Vionic Group LLC, Novato CA, USA) that is acceptable to adolescents with PFP. The orthoses have inbuilt arch support and varus wedging, with a variety of lengths and shapes to fit different footwear. Foot orthoses will be fit for comfort using our established algorithm. Participants will be fit with 2-4 pairs of foot orthoses in enclosed shoes they most commonly wear (e.g. school shoes, sports shoes [including running shoes, boots, cleats], casual shoes). The study practitioner fitting the foot orthoses (registered podiatrist or physiotherapist) will ensure that the adolescent’s footwear is appropriate to accommodate the foot orthoses, and will provide recommendations on suitable footwear if the adolescents and their parents wish to purchase new footwear. The orthoses can be transferred to other shoes (e.g. between different sports shoes) as needed. Foot orthoses will be fit to shoes as a pair (i.e. one in each shoe), regardless of whether the participant has unilateral or bilateral patellofemoral pain (PFP). Participants will be offered up to 3 appointments with the study practitioner in the first 3 months to fit the orthoses and make adjustments for comfort or to address any issues (e.g. rubbing, blisters), with the first appointment scheduled within 1-2 weeks after randomisation. One additional appointment will be offered over the remaining 6 months to refit or replace orthoses as needed (e.g. due to growth spurts). Each appointment will be approximately 30 minutes duration. If in-person attendance is not feasible for follow-up appointments where no foot orthoses prescription or adjustment is needed (e.g. due to transport issues), participants will be offered telehealth appointments. Participants will also be offered a pair of contoured flip-flops, slides or sandals to wear as an alternative to enclosed shoes and foot orthoses in warmer weather (Tide II Toe Post Sandal or Rejuvenate Recovery Sandal; Vionic, Vionic Group LLC, Novato CA, USA). Participants will be provided with a guide for using and adapting to the orthoses and contoured footwear (printed and electronic resources). Participants in Arm 1 will also receive the Advice intervention. The advice intervention aims to give adolescents brief, credible information about their PFP, and simple strategies to manage it. Participants in all three trial arms will receive the same advice intervention. The resources will explain what PFP is and what it means, what causes PFP, and simple self-management strategies for their knee pain. The resources will include: (i) a 1-page written summary; (ii) a graphical summary of key points; and (iii) a video summary presented by a health professional (e.g. physiotherapist) and an adolescent. The advice intervention resources have been adapted from existing resources, in consultation with the trial Consumer and Stakeholder Advisory Groups. Participants will be given the resources at the baseline appointment, and asked to review them in their own time. A follow-up zoom or phone call will be scheduled within two weeks of the baseline appointment, with the same health professional who conducts the screening assessment and gives the adolescent a diagnosis of PFP. During the call, they will go through the resources with the participant and their parent/guardian (if applicable) and answer any questions. Arm 2: Targeted physiotherapy + Advice The targeted physiotherapy intervention aims to provide adolescents with the skills to self-manage their PFP in the short- and long-term and build self-efficacy, using strategies tailored to their needs and impairments. The program uses education, behaviour change techniques and tools, exercise and pain-management strategies, and is based on interventions that have been tested in previous RCTs and cohort studies in adolescents with PFP, and adapted to the Australian context in consultation with the trial Consumer and Stakeholder Advisory Groups. The program consists of: (i) activity modification and load management; (ii) knee taping; (iii) exercise (tailored to the adolescent’s sport and physical activity demands, strength and movement impairments, and preferences); and (iv) psychologically informed videos (explaining pain; addressing beliefs about kinesiophobia, fear avoidance and pain catastrophising; explaining how to stay active; reframing negative thoughts into positive thoughts). Study practitioners (registered physiotherapists) will undergo training in how to select, tailor and prescribe each component of the program, to deliver an intervention that is targeted to each adolescent in terms of factors contributing to their PFP, sport and physical activity goals and demands, and acceptability to them (e.g. time commitment). Participants will be offered six sessions with the study practitioner over the 9-month trial. Up to 5 appointments will be scheduled over the first 3 months (initial appointment within 1-2 weeks of randomisation, subsequent appointments at 2 weeks, 1 month, 2 months and 3 months), with an additional appointment scheduled at approximately 6 months for longer-term follow-up and progression. Each appointment will be approximately 30 minutes duration. If in-person attendance is not feasible (e.g. due to transport issues), participants will be offered telehealth appointments (for some or all appointments). Participants will be provided with printed and electronic resources to accompany the components of the intervention. Participants in Arm 2 will also receive the Advice intervention (detailed above). Treatment adherence and fidelity Treatment adherence will be monitored across all three trial arms (as described under secondary outcomes). The fidelity of each of the three interventions will be evaluated by reviewing trial-specific treatment case report forms for each participant, and by observing a sample of participant intervention sessions during the first six months of the trial (video recorded; evaluated using a checklist of adherence and competence criteria specific to the intervention). General feedback points will be provided to all study practitioners based on outcomes of fidelity checks. Further training of study practitioners will be provided if issues with fidelity are identified early in the trial. Fidelity checks and feedback will be repeated in the second half of the intervention period.