What are the characteristics of and risks factors for adolescents with patellofemoral pain?

One in 14 school-aged adolescents has patellofemoral pain (PFP) (Smith et al 2018), making it the most common non-traumatic knee pain in this age group.

PFP is more common in active adolescents and girls but can affect adolescents of all ages and genders as well as those with a sedentary lifestyle.

Factors contributing to the onset and persistence of PFP are unique for each adolescent and may include load, landing mechanics, strength and sports specialisation.

Physiotherapists should sensitively explore the psychosocial factors and life stressors of adolescence, which may also contribute to PFP.

We propose that adolescents with PFP fall on a continuum stretching from recent onset PFP to longstanding PFP.

Those with recent onset PFP are typically still active in sport, despite their knee pain, and may respond well to simple self-management strategies.

Adolescents with longstanding PFP (longer than 12 months) experience frequent knee pain (often bilaterally), report low quality of life, commonly use pain medication and may have features of nociplastic pain.

Seventy per cent of adolescents with longstanding PFP stop or reduce their sport participation (Rathleff et al 2016), while 40 per cent continue to have symptoms after five years (Rathleff et al 2019).

These adolescents need a more comprehensive approach to assessment and management, as outlined in our review.

What factors are predictive of a poor prognosis for adolescents with patellofemoral pain?

Several factors may increase the risk of a poorer prognosis, including frequent knee pain, bilateral PFP, longer duration of PFP, female sex, moderate to severe anxiety or depressive symptoms, lower health-related quality of life and worse fear behaviours (Rathleff et al 2016, Holden et al 2021).

However, we do not have well-established cut points to help clinicians identify adolescents with a poor prognosis.

At present, the strongest predictor of longer- term outcomes is being ‘improved’ or ‘much improved’ after four weeks of treatment (Rathleff et al 2024).

Which assessments are recommended to guide diagnosis?

There are no definitive physical or imaging tests for PFP; therefore, diagnosis is typically based on clinical history, symptom presentation and exclusion of other sources of adolescent anterior knee pain (eg, lumbar/hip referral, red flags).

The core criterion for diagnosing PFP is pain around or behind the patella, aggravated by at least one activity that loads the patellofemoral joint (ie, weight-bearing knee flexion), such as squatting, climbing stairs, running or jumping (Crossley et al 2016).

The Sorting non-trauMatIc adoLescent knEe pain tool is useful for guiding assessment of adolescents with anterior knee pain and improves diagnostic accuracy (Guldhammer et al 2021).

Which assessments are recommended to guide management?

The initial clinical encounter is a pivotal moment in managing adolescents with PFP.

Creating a therapeutic environment where adolescents feel empowered to describe their pain story and taking time to discuss and explore potential contributors to their PFP helps adolescents feel listened to, validates their pain experience (Djurtoft et al 2024) and highlights priorities for management.

Key topics to explore may include their beliefs about why they have knee pain; loading history; recovery, sleep and nutrition; physical and mental health; and social and life circumstances. Informed by interview findings, physiotherapists can perform a targeted physical examination to guide treatment, which also helps adolescents feel that they’ve been thoroughly examined (Guldhammer et al 2021).

Patient-reported outcome measures can capture pain, function, quality of life and global change and can identify psychosocial impairments.

What interventions appear to be beneficial?

All adolescents with PFP should receive tailored education covering:

• a credible explanation of PFP including its nature and possible contributing factors (Djurtoft et al 2024)
• advice on load management and activity modification (Rathleff et al 2019)
• self-management strategies to modify activities and manage flare- ups (eg, activity ladder, pain monitoring scale and pain story map).

Additional interventions can be used in conjunction with education, such as lower limb exercises, psychologically informed videos, foot orthoses and footwear, and patellar taping.

What are some priorities for future research in this area?

Refining our understanding of adolescents with PFP—from recent onset to chronic cases—is essential for developing individualised assessment plans and improving treatment outcomes.

This includes establishing why adolescents often delay seeking care for their knee pain until it becomes longstanding and identifying strategies to promote early intervention.

High-quality randomised controlled trials are urgently needed to inform clinical guidelines and there are currently no studies on preventing PFP in adolescents.

Fundamentally, adolescents with PFP should be involved as partners in all future research, particularly co-designing prevention and management strategies.

>>Associate Professor Natalie Collins MACP is an APA Titled Sports and Exercise Physiotherapist and an associate professor in physiotherapy at the University of Queensland. She leads a research program focused on preventing persistence and progression of knee pain across the life span.

>>Professor Michael Skovdal Rathleff is a physiotherapist and director of the PRIMA Research Center at Aalborg University in Denmark. His work focuses on patient-centred approaches to improve health, function and quality of life across the life span.
 

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