The JBJS Quiz of the Month is a collection of 10 relevant questions from each orthopaedic subspecialty. The questions are drawn from JBJS Clinical Classroom, which houses over 4,500 questions and 3,100 learning resources. Take the Quiz to see how you score against your peers!

NOTE: This quiz does not earn users CME credits. The questions must be answered within Clinical Classroom to earn CME credits.

A 12-month-old child is referred for short stature. The child has a history of frequent respiratory tract infections. Examination reveals a short neck, coarse facies, and claw hands. Radiographs indicate flaring of the ribs and medial clavicle, anterior vertebral wedging, and odontoid hypoplasia. Which of the following is most likely to limit this child’s mobility?
  • Chronic knee dislocations
  • Chronic knee dislocations may be found in several conditions, including arthrogryposis and Larsen syndrome. Hurler syndrome has occasionally been associated with dislocations of the hips.

  • Decreased hip extension
  • Hurler syndrome is commonly associated with joint stiffness, notably of the hips, that mostly affects hip extension that is required for fluid gait.

  • Progressive neurological deterioration
  • While children with Hurler syndrome may have a deceleration in cognitive development, this disorder is not typified by neurological deterioration.

  • Developmental hip dysplasia
  • Hurler syndrome is characterized by hip stiffness but not hip dysplasia.