A 17-year-old male comes to the clinic because of a 2-month history of aching pain in the front of his right knee. He says the pain worsens when she sits for long periods, such as during car rides, and when she goes up or down stairs. The pain is also triggered during squatting, especially while powerlifting. He denies any trauma, instability, swelling, locking, or catching of the knee. On physical examination, there is no effusion, erythema, or deformity. The knee has full range of motion. There is mild peripatellar tenderness and pain with patellar compression, but no tenderness over the tibial tuberosity or medial knee. Strength and neurovascular exams are normal. Which of the following is the most likely diagnosis?
A) Osgood-Schlatter disease
B) Patellar tendonitis
C) Patellar tendon rupture
D) Patellofemoral pain syndrome
E) Pes anserine bursitis
