A 13-month-old boy is brought to the emergency department by his aunt due to leg pain. He was dropped off at her house this morning by the mother and since then has cried whenever his left leg is touched, refuses to stand up, and has been irritable. Treatment with acetaminophen has not provided any relief. According to the aunt, the patient was born at home, and his mother received no prenatal care during her pregnancy. He was breastfed exclusively until age 6 months. The patient has had no routine health care and takes no daily medications or supplements. The toddler's father is unknown; his mother had a forearm and wrist fracture as a child. Weight is at the 5th percentile and height is at the 50th percentile. On physical examination, the left distal thigh has mild swelling and point tenderness. The skin has no bruising, but beefy erythematous plaques with satellite papules are present in the diaper area. X-ray of the left thigh reveals a medial metaphyseal corner fracture of the distal femur. Which of the following is the most likely cause of this patient's x-ray findings?

Question

A 13-month-old boy is brought to the emergency department by his aunt due to leg pain.  He was dropped off at her house this morning by the mother and since then has cried whenever his left leg is touched, refuses to stand up, and has been irritable.  Treatment with acetaminophen has not provided any relief.  According to the aunt, the patient was born at home, and his mother received no prenatal care during her pregnancy.  He was breastfed exclusively until age 6 months.  The patient has had no routine health care and takes no daily medications or supplements.  The toddler's father is unknown; his mother had a forearm and wrist fracture as a child.  Weight is at the 5th percentile and height is at the 50th percentile.  On physical examination, the left distal thigh has mild swelling and point tenderness.  The skin has no bruising, but beefy erythematous plaques with satellite papules are present in the diaper area.  X-ray of the left thigh reveals a medial metaphyseal corner fracture of the distal femur.  Which of the following is the most likely cause of this patient's x-ray findings?

Quizplus · Accepted Answer

11ec25c8_d737_ae34_bc81_7de041f1095c_MD0003_00 This patient has a metaphyseal corner fracture. Such fractures, which result from forcible pulling or twisting of an extremity, are rarely incidental and are a red flag for child abuse. metaphyseal corner fracture Children with chronic medical problems, as well as those in an unstable family situation (eg, single-parent home, domestic violence), are at increased risk for child abuse. In addition, caregivers who were abused or neglected themselves during childhood (as is possibly the case with this patient's mother, who herself had fractures as a child) are more likely to continue this behavior with their own children. Once child abuse is suspected, the next step in management is to perform a skeletal survey to look for additional occult fractures. Findings concerning for abuse include multiple fractures at various stages of healing, posterior rib fractures, skull fractures, and femur fractures in nonambulatory infants. Additional evaluation includes funduscopy to evaluate for retinal hemorrhages plus a CT scan of the head to assess for intracranial bleeding. (Choice B) Anterior tibial bowing (saber shin) is a finding of late congenital syphilis, which can develop due to persistent inflammation or scarring from untreated infection in a patient with no routine health care and whose mother had no prenatal care. Other manifestations include frontal bossing, saddle nose, gummas (granulomatous lesions), and others (not seen in this patient). Metaphyseal corner fractures are not a feature of congenital syphilis. (Choice C) Langerhans cell histiocytosis can present with a rash similar to candida diaper dermatitis (eg, beefy erythematous plaques with satellite papules in the diaper area, as seen in this patient) but causes lytic bone lesions, not a metaphyseal corner fracture. lytic bone lesions (Choice D) Children with osteogenesis imperfecta have a defect in type I collagen that predisposes them to multiple fractures following minimal trauma. Other characteristic findings include blue sclerae, excessive bruising, and short stature, none of which are seen in this patient. (Choice E) X-ray findings seen in rickets (vitamin D deficiency) include osteopenia, metaphyseal beaking and fraying, and epiphyseal widening, not present on this patient's x-ray. metaphyseal beaking and fraying Educational objective: Metaphyseal corner fractures occur when an extremity is pulled or twisted. These fractures are a red flag for child abuse and should prompt a skeletal survey to evaluate for additional occult fractures. References: Orthopaedic aspects of child abuse. (http://www.ncbi.nlm.nih.gov/pubmed/23395044)

A 13-Month-Old Boy Is Brought to the Emergency Department by His