What is Patellofemoral Pain Syndrome (Runner's Knee)?

Patellofemoral Maltracking Dynamics

The patella articulates with the femoral trochlear groove during knee flexion. Muscular imbalance—specifically weakness of the vastus medialis obliquus (VMO) combined with hip abductor deficiency or foot overpronation—causes the patella to track laterally. Elevated focal contact pressures induce retropatellar chondral irritation and subchondral nerve firing.

High-Incidence Populations

Highly prevalent among recreational runners, court athletes, and adolescents with elevated pelvic Q-angles, often categorized under anterior knee pain spectrums.

Primary Clinical Hallmarks

• Diffuse peripatellar and retropatellar aching during eccentric loading (descending stairs)
• Stiffness and discomfort following prolonged seated flexion ('movie theater sign')
• Retropatellar crepitus and grinding sensations during deep squats
• Mild occasional joint puffiness without marked gross effusion

Frequently Asked Questions

Is surgery routinely warranted for runner's knee?

Surgery is rarely necessary; comprehensive targeted physical therapy focusing on closed-chain VMO strengthening and hip abductor stabilization resolves over 90% of cases.

How does patellofemoral pain relate to chondromalacia?

Chondromalacia patellae describes histological softening and fibrillation of the retro-patellar cartilage, which frequently underlies patellofemoral pain syndrome.