Progressive knee pain in a young football player

An 11-year-old male football player had a 3-month history of persistent right thigh pain. He had continued to play regularly despite intermittent pain and cramping, but symptoms had worsened significantly and he had lately had occasional flulike symptoms and mild fever. X-rays and an ultrasound vascular study were normal, but an MRI revealed a possible femoral sarcoma. A biopsy demonstrated osteomyelitis of the right femur with an adjacent abscess. After a course of parenteral antibiotics, he recovered fully and returned to competitive football. Osteomyelitis in adolescents can lead to a variety of nonspecific symptoms, and heightened awareness is important for accurate diagnosis and treatment.