A 17-year-old female distance runner has diffuse anterior knee pain that worsens when walking up or down stairs or squatting. There is no history of acute trauma and no knee effusion. What is the most likely diagnosis?

A 17-year-old female distance runner has diffuse anterior knee pain that worsens when walking up or down stairs or squatting. There is no history of acute trauma and no knee effusion. What is the most likely diagnosis?

• A. Anterior Cruciate Ligament Tear
• B. Osteoarthritis of the knee joint
• C. Medial meniscal tear
• D. Patellofemoral syndrome

Answer: (D)

Pain located at the front of the knee that worsens with bending activities like stairs or squatting in a young, active runner points to patellofemoral pain syndrome. This overuse or maltracking of the patella against the femur causes discomfort around the patellofemoral joint, especially when the knee is in deep flexion. The absence of swelling or a traumatic event fits this pattern, as there’s no acute effusion or instability. In contrast, an ACL tear typically follows a twisting injury with a sense of giving way and immediate swelling; osteoarthritis is unlikely in a 17-year-old and would usually present with stiffness, crepitus, and persistent joint changes; a medial meniscal tear often presents with joint line tenderness, locking, or catching after twisting, and may have swelling. The clinical picture here—anterior knee pain with stairs and squatting and no effusion or trauma history—fits patellofemoral pain syndrome best.

Pain located at the front of the knee that worsens with bending activities like stairs or squatting in a young, active runner points to patellofemoral pain syndrome. This overuse or maltracking of the patella against the femur causes discomfort around the patellofemoral joint, especially when the knee is in deep flexion. The absence of swelling or a traumatic event fits this pattern, as there’s no acute effusion or instability.

In contrast, an ACL tear typically follows a twisting injury with a sense of giving way and immediate swelling; osteoarthritis is unlikely in a 17-year-old and would usually present with stiffness, crepitus, and persistent joint changes; a medial meniscal tear often presents with joint line tenderness, locking, or catching after twisting, and may have swelling. The clinical picture here—anterior knee pain with stairs and squatting and no effusion or trauma history—fits patellofemoral pain syndrome best.