Ossification of the upper end of the humerus involves three separate centres: one for the head, one for the greater tubercle, and one for the lesser tubercle. These three centres fuse with each other to form a single composite epiphysis, which then fuses with the diaphysis at what approximate age?

• A 6 to 8 years
• B 11 to 13 years
• C 19 to 21 years ✓
• D 24 to 26 years

Explanation

The centres for the head, greater tubercle and lesser tubercle appear at roughly 1, 3 and 5 years respectively, coalesce into a single composite epiphysis by about the seventh year, and that epiphysis unites with the shaft at approximately 19 to 21 years, earlier in females. The 6 to 8 year figure applies to fusion of the three centres with each other, not to the shaft, which is the distractor tested here. Late union matters in assessing adolescent shoulder radiographs.

Reference: BD Chaurasia's Human Anatomy, Volume 1: Upper Limb and Thorax, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.