A 13-year-old boy is brought to the clinic by his mother for evaluation of hip pain. For the past 3 weeks, he has had mild pain in his right hip with an associated limp, which he attributed to a muscle strain from skateboarding. The patient fell while skateboarding last night, which resulted in worsened pain. The patient has taken ibuprofen with some improvement in his pain. He has no chronic medical conditions but did have a runny nose and nasal congestion for a few days last week. Height and weight are in the 95th and 50th percentiles, respectively. Temperature is 37 C (98.6 F). The patient walks with a limp to the examination table, avoiding bearing weight on his right leg. Examination of the right hip shows limited range of motion with internal rotation. There is full range of motion on the left side. Frog-leg lateral x-ray of bilateral hips is shown below: Which of the following is the most likely diagnosis in this patient?

Question

A 13-year-old boy is brought to the clinic by his mother for evaluation of hip pain.  For the past 3 weeks, he has had mild pain in his right hip with an associated limp, which he attributed to a muscle strain from skateboarding.  The patient fell while skateboarding last night, which resulted in worsened pain.  The patient has taken ibuprofen with some improvement in his pain.  He has no chronic medical conditions but did have a runny nose and nasal congestion for a few days last week.  Height and weight are in the 95th and 50th percentiles, respectively.  Temperature is 37 C (98.6 F).  The patient walks with a limp to the examination table, avoiding bearing weight on his right leg.  Examination of the right hip shows limited range of motion with internal rotation.  There is full range of motion on the left side.  Frog-leg lateral x-ray of bilateral hips is shown below:  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_d2c8_1e94_bc81_1bbcc9b8ee51_MD0003_00 This patient has slipped capital femoral epiphysis (SCFE), characterized by anterolateral and superior displacement of the proximal femur along the physis (growth plate). During periods of accelerated growth (eg, early adolescence), the physis is relatively weak due to its cartilaginous composition and rapid expansion. Although obesity is a significant risk factor (due to increased mechanical strain on the physis), SCFE can also occur in tall, thin adolescents during a growth spurt (as seen in this patient). displacement of the proximal femur Classic presentation is an insidious onset of dull hip pain and limp. Minor trauma, as seen in this patient, can sometimes exacerbate the pain and prompt the patient to seek medical attention. On examination, patients hold the affected hip in passive external rotation and exhibit decreased internal rotation, abduction, and flexion. Hip radiographs (anteroposterior and frog-leg lateral views) are diagnostic. Bilateral hips should be imaged for comparison and assessed for contralateral displacement. Treatment is immediate stabilization of the physis with surgical fixation to avoid the risk of avascular necrosis. (Choice A) Femoral neck fracture most commonly occurs in elderly patients with osteopenia. In children, the fracture is usually secondary to high-impact trauma (eg, motor vehicle collision). Presentation includes hip pain and decreased range of motion; however, x-ray would show a fracture line, not seen in this case. Femoral neck fracture (Choice B) Legg-Calvé-Perthes disease, or idiopathic avascular necrosis of the hip, most commonly affects boys age 5-7 and presents with insidious onset of hip pain and limp. X-ray may be normal in early disease or show fragmentation of the femoral head, not displacement of the femoral head. Legg-Calvé-Perthes disease (Choice C) Osteomyelitis typically presents with fever, bony tenderness, and swelling. Initial x-ray may be normal, but evidence of bony destruction is usually present within 1-2 weeks of symptom onset. Osteomyelitis (Choice E) Transient synovitis involving the hip is an inflammatory condition that presents in children age 3-8 with hip pain and limp, often after a viral illness. Symptoms typically improve (not worsen) over weeks, and x-ray is normal or may show joint effusion. Educational objective: Slipped capital femoral epiphysis (SCFE), which causes hip pain and limp, is characterized by displacement of the proximal femur relative to the femoral head along the growth plate. Obesity is a risk factor, but SCFE may also be seen in tall, thin adolescents during periods of accelerated growth. References: Slipped capital femoral epiphysis: diagnosis and management. (http://www.ncbi.nlm.nih.gov/pubmed/28671425)

A 13-Year-Old Boy Is Brought to the Clinic by His