Which condition is characterized by anterior knee pain, especially when walking downstairs, in a 15-year-old girl?

The condition characterized by anterior knee pain, particularly when walking downstairs in a 15-year-old girl, is chondromalacia patellae. This condition involves the softening and deterioration of the cartilage on the underside of the kneecap (patella). It is commonly seen in adolescents and young adults who are physically active and can manifest as pain during activities that put stress on the knee, especially movements that involve bending the knee, such as descending stairs.

In this situation, the specific emphasis on pain during descending stairs points towards chondromalacia patellae, as it typically results in discomfort during activities that place increased pressure on the patellofemoral joint. The young female demographic is particularly susceptible to this condition due to anatomical and physiological factors, including greater Q-angle and hormonal influences on joint stability.

Other conditions listed, like Osgood-Schlatter disease, typically present with pain at the tibial tuberosity due to traction apophysitis and is more common in younger boys. Patellar tendinitis, commonly seen in athletes, refers to pain related to the patellar ligament rather than the cartilage. Runner's knee is a more general term that encompasses a variety of knee pain conditions but doesn’t point specifically to