Extracorporeal Shock Wave Therapy in Patellofemoral Pain Syndrome

Effectiveness of Extracorporeal Shock Wave Therapy in Patellofemoral Pain Syndrome: A Randomized Controlled Trial

Patellofemoral pain syndrome (PFPS) is a common cause of anterior knee pain and functional limitations in physically active individuals. Exercise-based rehabilitation is considered the primary treatment approach, yet a proportion of patients experience persistent symptoms. Extracorporeal shock wave therapy (ESWT) is a non-invasive modality that may reduce pain through neuromodulation and tissue-level biological responses.

This randomized controlled trial evaluated the effects of ESWT on knee pain and function in adults with PFPS. Thirty-six participants aged 18-45 years were randomly assigned to one of three groups: Exercise, Exercise plus ESWT, or ESWT alone. The exercise program consisted of home-based hip and knee strengthening performed at least three times per week for four weeks. ESWT was administered as five radial shock wave sessions at five-day intervals around the peripatellar soft tissues.

Outcomes included worst knee pain measured by the Visual Analogue Scale and functional status measured by the Kujala Patellofemoral Score at baseline, week 1, and week 8. All groups demonstrated significant improvements over time, with no significant differences between groups. The treatment was well tolerated.

This trial was retrospectively registered after patient enrollment was completed.

Inclusion Criteria:

• Age 18 to 45 years.
• Clinical diagnosis of patellofemoral pain syndrome (PFPS) characterized by anterior or retropatellar knee pain lasting at least 8 weeks.
• Pain provoked during at least two of the following activities: running, jumping, squatting, stair climbing, or prolonged sitting.
• Worst knee pain score of ≥3 on the Visual Analog Scale (0-10).
• Ability to understand and follow the exercise program and assessment procedures.
• Provided written informed consent.

Exclusion Criteria:

• Evidence of intra-articular knee pathology other than grade 1-2 meniscal changes or grade 1 chondromalacia patella on MRI.
• Clinical signs of patellar instability.
• Localized tenderness indicating alternative diagnoses (e.g., patellar tendinopathy, iliotibial band syndrome, pes anserine bursitis).
• History of knee surgery on the affected side.
• Intra-articular injections (e.g., corticosteroids, hyaluronic acid, PRP) within the past 6 months.
• Neurological or rheumatological disorders affecting the lower extremity.
• Active infection, open wound, tumor, or severe dermatological condition at or near the ESWT application site.
• Pregnancy.