List key features commonly seen with patellofemoral pain syndrome.

• A. Anterior knee pain worsened by squatting and stairs, theater sign, crepitus, lateral tracking of the patella
• B. Pain at the posterior knee with calf swelling
• C. Medial knee pain with valgus deformity
• D. Hip pain with groin radiation

Answer: (A)

Patellofemoral pain syndrome shows anterior knee pain that is triggered by knee-bending activities such as squatting and stairs, often described as a theater sign after sitting for a long time. You’ll commonly find crepitus around the patellofemoral joint and a sense that the patella tracks laterally. These features reflect stress and maltracking at the patellofemoral articulation, often from overuse or muscle imbalance, causing pain with bending the knee. The other patterns describe problems in different areas—posterior knee pain with calf swelling suggests vascular or calf issues, medial knee pain with valgus deformity points to medial knee structures such as the MCL or medial meniscus, and hip pain with groin radiation indicates hip pathology.