At 1 year of age, the number of carpal bones seen in skiagram of the hand is: COMEDK 08
**Core Concept:** Carpal bones are a group of 8 small bones that form the carpal or wrist bones in the human body. They are located between the radius and ulna bones, and help facilitate hand movement. In infants, there are fewer carpal bones compared to adults.
**Why the Correct Answer is Right:** At 1 year of age, the typical number of carpal bones seen in a skiagram of the hand is 7. This includes the scaphoid, lunate, triquetral, radio-carpal, and radioulnar joints. The correct answer is not mentioned directly in the options, but we can deduce it from the given choices.
**Why Each Wrong Option is Incorrect:**
A. 8: This is the correct number of carpal bones in adults, not infants.
B. 7: The number of carpal bones is not exactly 7 at 1-year-old, making this incorrect.
C. 6: Similar to option A, this is the number of carpal bones in adults, not infants.
D. 5: This is the number of carpal bones in some animals, not humans.
**Why the Correct Answer is Right:** In infants, the ossification of the carpal bones is incomplete, resulting in fewer bones compared to adults. The scaphoid bone begins ossification at around 6 months of age, while the lunate and triquetral bones fuse together after birth.
**Correct Answer:** 7 (The scaphoid, lunate, triquetral, radio-carpal, and radioulnar joints.)
**Clinical Pearl:** Understanding the developmental changes in the carpal bones is crucial for interpreting radiographs of infants and young children, as the presence of these bones can help differentiate between normal variants and pathological conditions. This knowledge is essential for diagnosing conditions like slipped capital femoral epiphysis (SCFE) and developmental dysplasia of the hip (DDH), where radiological findings may overlap with incomplete carpal bone development.