|
Year |
2006 |
|---|---|
|
Question Number |
226 |
|
Category |
Orthopaedic Science |
Question
Achondroplasia results from abnormal chondrocyte functions due to FGF-3 receptor in the growth plate. What region is affected in the growth plate as shown in Figure 87?
1- A
2- B
3- C
4- D
5- E
Figures
Answer (click for answer)
The correct answer: 3
Figure 87 depicts a physis with a demarcation of the separate regions of the growth plate. Section C is the proliferative zone of the physis (just below the reserve zone (B) and above the hypertrophic zone (D). The fact that Achondroplasia affects the proliferative zone of the physis is a fact that needs to be memorized. This disruption in chondrocyte proliferation (column formation) affects long bone growth but has no affect on intramembranous bone growth (bone width is normal). (See page 13 in Miller for diagram of physis).
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