Comparison of Exercise Therapies for Patellofemoral Pain

Study Overview
=================
Brief Summary
-----------------
Patellofemoral Pain (PFP) is a common knee problem, primarily affecting adolescents and young adults. PFP is characterised by significant retropatellar and/or peripatellar pain and impairment of function and quality of daily life. Exercise therapy is unequivocally recommended as a core component of the management of PFP. Different exercise types (e.g. quadriceps strengthening, hip strengthening and functional/neuromuscular exercises) have been investigated, with knee and hip strengthening exercises as the most common and recommended types. These exercises approaches produce similar small to moderate effects on pain and physical function. However, the PFP population is very heterogeneous and one-size-fits-all-approaches presumably are sub-optimal because the heterogeneity is ignored. The heterogeneity probably explains the overall limited beneficial effects of exercise, and the lack of differences in direct comparisons of different exercise types. In that sense, it is not unlikely that certain patient characteristics may predict outcome success of either a hip training program or a training program that focus on the quadriceps but this remains to be shown. This study has two aims: To assess the comparative effectiveness of two different exercise programs (Quadricep Exercise [QE] vs. Hip Exercise [HE]) on self-reported pain and function in individuals with PFP. To explore candidate patient characteristics that predict differential responses to the two exercise programs (QE vs HE) on self-reported pain and physical function in individuals with PFP. According to the study aims we pursue the following hypothesis: - QE and HE have equivalent efficacy on self-reported pain after 12 weeks of treatment in patients with PFP. The second study aim is to explore possible candidate patient characteristics that may associate with differential outcomes. As this is exploratory, the pursuit of this aim is hypothesis-free.

Official Title
-----------------
Comparative Effectiveness of Therapeutic Hip and Knee Exercise for Atellofemoral Pain: A Pragmatic Randomised Trial

Conditions
-----------------
Patellofemoral Pain Syndrome

Intervention / Treatment
-----------------
* Other: Quadriceps Exercise program
* Other: Hip Exercise program


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: A clinical diagnosis of PFP in at least one knee Visual analogue score rating of pain during activities of daily living during the previous week at a minimum of 3 on a 10 cm scale. Insidious onset of symptoms unrelated to trauma and persistent for at least 4 weeks. Pain in the anterior knee associated with at least 3 of the following: During or after activity Prolonged sitting Stair ascent or descent Squatting Exclusion Criteria: Meniscal or other intra-articular injury Cruciate or collateral ligament laxity or tenderness Patellar tendon, iliotibial band, or pes anserine tenderness Osgood-Schlatter or Sinding-Larsen-Johansson syndrome History of recurrent patellar subluxation or dislocation History of surgery to the knee joint History of head injury or vestibular disorder within the last 6 months

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Eligible participants will be randomly assigned (1:1) to one of the two following groups: QE - quadriceps exercise program HE - hip exercise program
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Quadriceps Exercise program<br>The Quadricepts Exercise (QE) program runs for 12 weeks, with exercise sessions 3 times per week. Each training session is scheduled to last approximately 30 minutes. The exercise program is home based with monthly supervision visits at the clinic. | Other: Quadriceps Exercise program<br>* The exercise program is initiated at an individual clinical visit. An experienced physiotherapist introduces the participant to the exercise program and provides instructions to the individual exercises. An experienced physiotherapist provides the monthly supervision visits. The program details can be requested rom the responsible party. In brief the QE-program consists of: - A short warm-up and 3 specific exercises for the quadriceps muscle Progression of the exercise intensity is done by adding (additional) external loads, such as elastic rubber bands, free weights, etc.<br>|
| Active Comparator: Hip Exercise program<br>The Hip Exercise (HE) program runs for 12 weeks, with exercise sessions 3 times per week. Each training session is scheduled to last approximately 30 minutes. The exercise program is home based with monthly supervision visits at the clinic. | Other: Hip Exercise program<br>* The exercise program is initiated at an individual clinical visit. An experienced physiotherapist introduces the participant to the exercise program and provides instructions to the individual exercises. An experienced physiotherapist provides the monthly supervision visits. The program details be requested rom the responsible party. In brief the HE-program consists of: - A short warm-up and 3 specific exercises for the hip abductor and extensor muscles Progression of the exercise intensity is done by adding (additional) external loads, such as elastic rubber bands, body weight etc.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in the KUJALA scoring questionnaire | The Kujala Patellofemoral Scale - sometimes called the anterior knee pain scale - is disease specific validated disability scale ranging from 0 (complete disability) to 100 (fully functional). It is a 13-item self-report questionnaire that documents response to 6 activities (walking, running, jumping, climbing stairs, squatting, and sitting for prolonged periods with knees bent), as well as symptoms such as limp, inability to weight bear, swelling, abnormal patellar movement, muscle atrophy, and limitations in knee flexion. | week 12 and 26 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in the KOOS questionnaire | The Knee injury and Osteoarthritis Outcome Score (KOOS) is used to assess patient-reported knee-related symptoms. The KOOS is a patient-reported outcome measurement instrument developed to assess the patient's opinion about their knee and associated problems.KOOS comprises of 42 items in 5 separately scored subdomains: KOOS Pain (9 items), KOOS Symptoms (7 items), Function in daily living (KOOS Function; 17 items), Function in Sport and Recreation (5 items), and Knee-related Quality of Life (4 items). The previous week is the time period considered when answering the questions, and the questions relate to one knee (the target knee in this trial). | Week 12 and 26 | 
| Change fom baseline in isometric muscle strength of hip abductors, hip external rotators, hip extensors, and quadriceps | Isometric muscle strength of hip abductors, hip external rotators, quadriceps, and hamstrings is performed by using a handheld dynamometer following a previously published testing protocol. | Week 12 | 
| Change fom baseline in the Dynamic Assessment of Pain test | The Dynamic Assessment of Pain Test is a simple performance test with an integrated pain score, designed to provide useful information for monitoring treatment progress and evaluating treatment effects in clinical physiotherapy practice. The patient is asked to perform as many squatting movements (both legs) as possible within 30 seconds. The knees should reach approximately 90 degrees of flexion and full extension for each squat. This is supervised by the rater. There outcome of the test is the knee pain during the test on a 0-10 Numeric Rating Scale (NRS) rated immediately after the test. | Week 12 | 
| Change fom baseline in the Pain Self-Efficacy Questionnaire | The pain self-efficacy questionnaire is a 10-item questionnaire developed to assess the confidence people with pain have in performing activities while in pain. It is applicable to all persisting pain presentations, and covers a range of functions. Confidence in performing activities are rated on a 7-point (0-6) Likert scale with 0 representing not at all confident and 6 representing completely confident. A total score is calculated by summing the answers producing a score between 0 and 60. Higher scores reflect stronger self-efficacy beliefs. | Week 12 and 26 | 
| Change fom baseline in the EuroQoL Questionnaire | The EuroQoL questionnaire is a standardised patient-reported instrument for use as a measure of health related quality of life. | Week 12 and 26 | 
| Transition Questionnaire of global perceived effect on overall health, pain, and function | The Transition Questionnaire of global perceived effect is an adaptive questionnaire in which the participants initially answer if their current state is unchanged, worse or better compared to the baseline visit. An unchanged equals a transition score of 0. If the participant answers worse, he/she is asked to rate the degree of worsening on a 7 point Likert scale, and the corresponding scores range from -1 to -7. Correspondingly, if a participant answers better, he/she is asked to rate the degree of improvement on a 7 point Likert scale, and the corresponding scores range from 1 to 7. Thus the Transition score range from -7 (worsening) to 7 (improvement), with the mid-point - 0 - representing no change. The transition scale is used to assess overall knee related health status. | Week 12 and 26 |