Kneecap pain (patellofemoral)

Kneecap pain (patellofemoral) syndrome (PFPS) — "runner's knee" — is diffuse anterior knee pain originating from the interface between the patella (kneecap) and the trochlear groove of the femur. It is among the most common knee conditions seen in active adolescents and young adults. When the patella tracks abnormally in the groove — due to muscle imbalances, hip weakness, or structural anatomy — excessive pressure on the cartilage causes pain.

Pain is characteristically worse with stairs, prolonged sitting (the "movie sign"), squatting, and running. It is not a single diagnosis but a symptom complex with multiple contributing factors.

Peripatellar or retropatellar pain, positive Clarke's sign (pain with patellar compression against the trochlear groove), and pain during a single-leg squat. Assessment of hip abductor strength and foot pronation is important for identifying contributing factors. MRI is obtained when cartilage damage (chondromalacia patella) or structural pathology is suspected.

1. Patellar taping / bracing

   McConnell taping or a patellar tracking brace provides symptom relief and biofeedback during rehabilitation.

2. NSAIDs

   Acute symptom control.

Surgery is rarely indicated for PFPS. When significant chondromalacia or structural malalignment (trochlear dysplasia, high TT-TG distance) is identified and symptoms persist after comprehensive conservative care, procedures to address the underlying anatomy are considered.

External patient-education references and related OSI pages for additional background:

• Britannica — Knee (anatomy)
• AAOS OrthoInfo — patient education library
• OSI glossary — orthopedic terminology in plain language