A 7-year-old boy is brought to the emergency department due to right leg pain. His mother says that he was running around the house and fell on the carpet an hour ago. The patient has been crying and experiencing thigh pain since the fall. He did not hit his head or lose consciousness. Medical history is notable for 3 fractures after seemingly minor injuries. Temperature is 36.7 C (98 F), blood pressure is 100/60 mm Hg, pulse is 148/min, and respirations are 20/min. On physical examination, the patient is crying but is alert and cooperative. His teeth appear translucent and gray but he otherwise appears well-kept. There is hyperlaxity of the joints of the hands, and upper extremity strength is 5/5 bilaterally. The right thigh is markedly tender to palpation with obvious deformity. X-ray demonstrates fracture of the proximal femur and does not involve the growth plate, which appears normal. Which of the following is most likely diagnosis in this patient?

Question

A 7-year-old boy is brought to the emergency department due to right leg pain.  His mother says that he was running around the house and fell on the carpet an hour ago.  The patient has been crying and experiencing thigh pain since the fall.  He did not hit his head or lose consciousness.  Medical history is notable for 3 fractures after seemingly minor injuries.  Temperature is 36.7 C (98 F), blood pressure is 100/60 mm Hg, pulse is 148/min, and respirations are 20/min.  On physical examination, the patient is crying but is alert and cooperative.  His teeth appear translucent and gray but he otherwise appears well-kept.  There is hyperlaxity of the joints of the hands, and upper extremity strength is 5/5 bilaterally.  The right thigh is markedly tender to palpation with obvious deformity.  X-ray demonstrates fracture of the proximal femur and does not involve the growth plate, which appears normal.  Which of the following is most likely diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_d742_3598_bc81_234f0779d96c_MD0003_00 This patient has osteogenesis imperfecta (OI), an autosomal dominant connective tissue disorder commonly caused by a type I collagen mutation. Type I collagen is a critical structural component of tissues in the bone, sclerae, skin, and teeth. OI has a varying spectrum of severity, from mild (type I) to lethal (type II) disease. Due to defective collagen in osteoid (extracellular bone matrix), patients often begin having frequent fractures from minor trauma once they become mobile (around age 1). Many patients with OI also have dentinogenesis imperfecta, an opalescent blue-gray or yellow-brown discoloration of the teeth caused by discolored dentin shining through translucent and weak enamel. Joints are often hypermobile due to ligamentous laxity. Scleral thinning can lead to the appearance of blue sclerae; other manifestations depend on the severity of the disorder and may include hearing loss and short stature. dentinogenesis imperfecta blue sclerae (Choice A) Frequent fractures caused by minor trauma should raise suspicion for child abuse. In addition, poor dental hygiene can be a sign of neglect. However, poor dental hygiene typically presents with dental caries (ie, well-defined, painful areas of decay) rather than dentinogenesis imperfecta. In addition, this child is well-kept and has features (eg, joint hypermobility) suggestive of an underlying disorder. (Choice B) Duchenne muscular dystrophy causes proximal muscle weakness, which with the additional decreased bone density associated with glucocorticoid treatment, may predispose patients to falls and subsequent frequent fractures. This patient has no muscle weakness. (Choice C) Ehlers-Danlos syndrome is a connective tissue disorder caused by defective type V collagen. This defect causes patients to have joint hypermobility (eg, subluxation, dislocation) but not recurrent fractures. (Choice E) Paget disease of bone occurs due to accelerated bone remodeling. Symptomatic patients can have bone pain and recurrent fractures due to excessive remodeling; however, this disorder is more common in adults and has no associated dental abnormalities. (Choice F) Calcipenic rickets (ie, deficient bone mineralization) can present with fractures and dental enamel hypoplasia in severe cases. However, patients have widened epiphyseal plates on x-ray due to impaired mineralization. In addition, there is no associated joint hypermobility. Educational objective: Osteogenesis imperfecta is an autosomal dominant connective tissue disorder that presents with frequent fractures, joint hypermobility, and dentinogenesis imperfecta. Additional features include blue sclerae, hearing loss, and short stature. References: Osteogenesis imperfecta. (http://www.ncbi.nlm.nih.gov/pubmed/28820180)

A 7-Year-Old Boy Is Brought to the Emergency Department Due