A middle-aged patient undergoes CT of the chest. Which part of the sternum is most likely to remain as a separate unfused piece even into late adult life?
- A Xiphoid process relative to the body ✓
- B Manubrium relative to the body
- C Upper segments of the sternal body relative to each other
- D No part remains unfused after 30 years
Correct answer: A. Xiphoid process relative to the body
Explanation
The xiphoid process ossifies late and its union with the body of the sternum occurs very slowly, often remaining incomplete until well past middle age and occasionally throughout life. The manubriosternal joint usually fuses in elderly individuals but is typically intact as a joint through adulthood, and the sternebrae of the body fuse with each other during childhood and adolescence. Recognising an unfused xiphisternal junction prevents misreading it as a fracture on imaging.
Reference: Gray's Anatomy for Students, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.