Knee pain: It’s not always the knee—slipped capital femoral epiphysis

Case presentation

A 9-year-old female presents with 5 weeks of progressively worsening left knee pain. There has been no known trauma and the family denies fever, rash, knee swelling or erythema, weakness, numbness, or incontinence. She is able to ambulate but, due to her pain, has been excused from physical education classes at school. She has seen numerous physicians, and multiple plain radiographs of the left knee were reported as “normal” according to the family. Her primary care provider obtained bloodwork (a complete blood count, erythrocyte sedimentation rate, and C-reactive protein), and the family was told this also was “normal.”

The child is afebrile and has normal, age-appropriate vital signs; her weight is 60 kg, with a height of 142 cm (body mass index of 22.5). Her examination shows a child who is not in distress until you ask her to ambulate. She complies and you notice a demonstrable limp to her left side. Her pelvis is stable and unremarkable. Your examination does not show any signs of trauma and there is no edema, erythema, warmth, or tenderness of her left knee. You perform range-of-motion maneuvers of the knee, which are normal. You examine her left thigh, which also appears unremarkable. Range of motion of her left leg at the hip produces knee pain and mild left hip pain. Her lower leg examination, including her ankle and foot, is unremarkable, including distal pulses. She has no cervical, thoracic, or lumbar findings. Her neurologic examination is nonfocal; she has equal strength of her lower extremities.

Imaging considerations